     1                                  ; ****************************************************************************
     2                                  ; sh386.s (sh3.s) - Retro Unix 386 v1 Shell - /bin/sh
     3                                  ; ----------------------------------------------------------------------------
     4                                  ;
     5                                  ; RETRO UNIX 386 (Retro Unix == Turkish Rational Unix)
     6                                  ; Operating System Project (v0.2) by ERDOGAN TAN (Beginning: 24/12/2013)
     7                                  ;
     8                                  ; Derived from 'Retro UNIX 8086 v1' source code by Erdogan Tan
     9                                  ; (v0.1 - Beginning: 11/07/2012)
    10                                  ;
    11                                  ; [ Last Modification: 29/05/2022 ]
    12                                  ;
    13                                  ; Derived from UNIX Operating System (v1.0 for PDP-11) 
    14                                  ; (Original) Source Code by Ken Thompson (Bell Laboratories, 1971-1972)
    15                                  ; ****************************************************************************
    16                                  ;
    17                                  ; <Preliminary Release of UNIX Implementation Document>
    18                                  ; <Isuse: D, Date: 17/3/1972, ID: IMO.1-1, Section: E.11> 
    19                                  ; <sh - command interpreter>
    20                                  ;
    21                                  ; ****************************************************************************
    22                                  
    23                                  ; Assembler: NASM v2.15
    24                                  ; ((nasm sh3.s -l sh3.txt -o sh3 -Z error.txt))
    25                                  
    26                                  ; sh3.s (29/05/2022, Retro UNIX 386 v1) -- (modified sh0.s) ---
    27                                  ; sh2.s (29/05/2022, Retro UNIX 386 v1.1 & v1.2) -- (modified sh1.s) --
    28                                  ; sh1.s (03/01/2016, Retro UNIX 386 v1.1)
    29                                  ; sh0.s (28/12/2015, Retro UNIX 386 v1, NASM 2.11, 32 bit version of 'sh.asm')
    30                                  ; SHELL03.ASM, 13/11/2013 - 27/06/2014 (sh.asm, Retro UNIX 8086 v1, MASM 6.11) 
    31                                  
    32                                  ; 12/01/2022 (Retro UNIX 386 v1.2)
    33                                  ; 13/10/2015
    34                                  ; 27/08/2015
    35                                  ; 24/08/2015
    36                                  ; 08/04/2014
    37                                  ; 13/11/2013
    38                                  
    39                                  ; UNIX v1 system calls
    40                                  _rele 	equ 0
    41                                  _exit 	equ 1
    42                                  _fork 	equ 2
    43                                  _read 	equ 3
    44                                  _write	equ 4
    45                                  _open	equ 5
    46                                  _close 	equ 6
    47                                  _wait 	equ 7
    48                                  _creat 	equ 8
    49                                  _link 	equ 9
    50                                  _unlink	equ 10
    51                                  _exec	equ 11
    52                                  _chdir	equ 12
    53                                  _time 	equ 13
    54                                  _mkdir 	equ 14
    55                                  _chmod	equ 15
    56                                  _chown	equ 16
    57                                  _break	equ 17
    58                                  _stat	equ 18
    59                                  _seek	equ 19
    60                                  _tell 	equ 20
    61                                  _mount	equ 21
    62                                  _umount	equ 22
    63                                  _setuid	equ 23
    64                                  _getuid	equ 24
    65                                  _stime	equ 25
    66                                  _quit	equ 26	
    67                                  _intr	equ 27
    68                                  _fstat	equ 28
    69                                  _emt 	equ 29
    70                                  _mdate 	equ 30
    71                                  _stty 	equ 31
    72                                  _gtty	equ 32
    73                                  _ilgins	equ 33
    74                                  _sleep	equ 34 ; Retro UNIX 8086 v1 feature only !
    75                                  _msg    equ 35 ; Retro UNIX 386 v1 feature only !
    76                                  _geterr	equ 36 ; Retro UNIX 386 v1 feature only !
    77                                  ; 12/01/2022 - Retro UNIX 386 v1.2
    78                                  ; Retro UNIX 386 v2 system calls
    79                                  _setgid	equ 37
    80                                  _getgid	equ 38
    81                                  _sysver	equ 39 ; (get) Retro Unix 386 version
    82                                  
    83                                  %macro sys 1-4
    84                                      ; 03/09/2015
    85                                      ; 13/04/2015
    86                                      ; Retro UNIX 386 v1 system call.
    87                                      %if %0 >= 2   
    88                                          mov ebx, %2
    89                                          %if %0 >= 3
    90                                              mov ecx, %3
    91                                              ;%if %0 = 4
    92                                              %if	%0 >= 4 ; 11/03/2022
    93                                  		mov edx, %4
    94                                              %endif
    95                                          %endif
    96                                      %endif
    97                                      mov eax, %1
    98                                      int 30h
    99                                  %endmacro
   100                                  
   101                                  ; Retro UNIX 386 v1 system call format:
   102                                  ; sys systemcall (eax) <arg1 (ebx)>, <arg2 (ecx)>, <arg3 (edx)>
   103                                  
   104                                  ;-----------------------------------------------------------------
   105                                  ;  text - code
   106                                  ;-----------------------------------------------------------------
   107                                  
   108                                  [BITS 32] ; 32-bit intructions (for 80386 protected mode)
   109                                  
   110                                  [ORG 0] 
   111                                  
   112                                  START_CODE:
   113                                  ;/ sh -- command interpreter
   114                                  
   115                                  	; 29/05/2022 - Erdogan Tan
   116                                  	; (Modified by using disassembled unix v2 'sh' code.)
   117                                  
   118                                  	;;27/12/2015
   119                                  	;;clear BSS
   120                                  	;mov	ecx, ((bss_end - bss_start) + 3) / 4
   121                                  	;sub	eax, eax
   122                                  	;mov	edi, bss_start
   123                                  	;rep	stosd
   124                                  s0:
   125 00000000 89E5                    	mov	ebp, esp
   126                                  		; mov sp,r5
   127 00000002 892D[FC0B0000]          	mov	[shellarg], ebp
   128                                  		; mov r5,shellarg / save orig sp in shellarg
   129 00000008 8B5D04                  	mov	ebx, [ebp+4]
   130 0000000B 803B2D                  	cmp	byte [ebx], '-'
   131                                  		; cmpb	*2(r5),$'- / was this sh called by init or loginx~
   132 0000000E 752E                    	jne	short s1
   133                                  		; bne 2f / no
   134                                  	sys	_intr, 0
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000010 BB00000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000015 B81B000000          <1>  mov eax, %1
    98 0000001A CD30                <1>  int 30h
   135                                  		; sys intr; 0 / yes, turn off interrupts
   136                                  	sys	_quit, 0
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 0000001C BB00000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000021 B81A000000          <1>  mov eax, %1
    98 00000026 CD30                <1>  int 30h
   137                                  		; sys quit; 0
   138                                  	sys	_write, 1, msg_unix_sh, msgsh_size
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000028 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 0000002D B9[78050000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 00000032 BA1B000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000037 B804000000          <1>  mov eax, %1
    98 0000003C CD30                <1>  int 30h
   139                                  s1: ;2:
   140                                  	sys	_getuid
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000003E B818000000          <1>  mov eax, %1
    98 00000043 CD30                <1>  int 30h
   141                                  		; sys	getuid / who is user
   142                                  	;and	eax, eax
   143 00000045 20C0                    	and	al, al
   144                                  		; tst r0 / is it superuser
   145 00000047 7507                    	jnz	short s2
   146                                  		; bne 2f / no
   147 00000049 C605[03060000]23        	mov	byte [_at], '#'
   148                                  		; movb $'#,at / yes, set new prompt symbol
   149                                  s2: ;2:
   150 00000050 837D0001                	cmp	dword [ebp], 1
   151                                  		; cmp (r5),$1 / tty input?
   152 00000054 7631                    	jna	short newline
   153                                  		; ble newline / yes, call with '-' (or with no command
   154                                  		      ; / file name)
   155 00000056 31DB                    	xor	ebx, ebx
   156                                  		; clr r0 / no, set tty
   157                                  	sys	_close
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000058 B806000000          <1>  mov eax, %1
    98 0000005D CD30                <1>  int 30h
   158                                  		; sys close / close it
   159 0000005F 8B5D08                  	mov	ebx, [ebp+8] ; arg 1
   160                                  		; mov 4(r5),0f / get new file name
   161 00000062 31C9                    	xor	ecx, ecx ; arg 2
   162                                  	sys	_open
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000064 B805000000          <1>  mov eax, %1
    98 00000069 CD30                <1>  int 30h
   163                                  		; sys open; 0:..; 0 / open it
   164 0000006B 7311                    	jnc	short s3
   165                                  		; bec 1f / branch if no error
   166 0000006D BE[A0050000]            	mov	esi, msgNotFound
   167 00000072 E8CC010000              	call	error
   168                                  		; jsr r5,error / error in file name
   169                                  		; <Input not found\n\0>; .even
   170                                  	sys	_exit
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000077 B801000000          <1>  mov eax, %1
    98 0000007C CD30                <1>  int 30h
   171                                  		; sys exit
   172                                  s3: ;1:
   173 0000007E C605[03060000]00        	mov	byte [_at], 0
   174                                  		; clr at / clear prompt character, if reading non-tty
   175                                  		   ; / input file
   176 00000085 EB1F                    	jmp	short newcom
   177                                  newline:
   178 00000087 803D[03060000]00        	cmp	byte [_at], 0
   179                                  		; tst at / is there a prompt symbol
   180 0000008E 7616                    	jna	short newcom
   181                                  		; beq newcom / no
   182                                  		; mov $1,r0 / yes
   183                                  nl:
   184                                  	sys	_write, 1, prompt, p_size
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000090 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000095 B9[01060000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 0000009A BA04000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000009F B804000000          <1>  mov eax, %1
    98 000000A4 CD30                <1>  int 30h
   185                                  	;sys	_write, 1, _at, 2
   186                                  		; sys write; at; 2. / print prompt
   187                                  newcom:
   188 000000A6 8B25[FC0B0000]          	mov	esp, [shellarg]
   189                                  		; mov shellarg,sp /
   190 000000AC BE[30060000]            	mov	esi, parbuf 
   191                                  		; mov $parbuf,r3 / initialize command list area
   192 000000B1 BF[2A0A0000]            	mov	edi, parp
   193                                  		; mov $parp,r4 / initialize command list pointers
   194 000000B6 31C0                    	xor	eax, eax
   195 000000B8 A3[1E0A0000]            	mov	[infile], eax ; 0	
   196                                  		; clr infile / initialize alternate input
   197 000000BD A3[220A0000]            	mov	[outfile], eax ; 0
   198                                  		; clr outfile / initialize alternate output
   199 000000C2 A2[1C0A0000]            	mov	[glflag], al ; 0
   200                                  	;mov	[glflag], ax ; 0
   201                                  		; clr glflag / initialize global flag
   202                                  newarg:
   203 000000C7 E838030000              	call	blank
   204                                  		; jsr pc,blank / squeeze out leading blanks
   205 000000CC E814030000              	call	delim
   206 000000D1 744E                    	je	short nch4 ; '\n', ';', '&'
   207                                  		; jsr r5,delim / is new character a ; \n or &
   208                                  		;     br 2f / yes
   209 000000D3 56                      	push	esi
   210                                  		; mov r3,-(sp) / no, push arg pointer onto stack
   211 000000D4 3C3C                    	cmp	al, '<'
   212                                  		; cmp r0,$'< / new input file?
   213 000000D6 7508                    	jne	short na1
   214                                  		; bne 1f / no
   215 000000D8 8935[1E0A0000]          	mov	[infile], esi
   216                                  		; mov (sp),infile / yes, save arg pointer
   217 000000DE EB0A                    	jmp	short na2
   218                                  	;mov	dword [esp], 0
   219                                  		; clr (sp) / clear pointer
   220                                  	;jmp	short nch1
   221                                  		; br 3f
   222                                  na1: ;1:
   223 000000E0 3C3E                    	cmp	al, '>'
   224                                  		; cmp r0,$'> / new output file?
   225 000000E2 7517                    	jne	short nch0
   226                                  	;jne	short newchar
   227                                  		; bne newchar / no
   228 000000E4 8935[220A0000]          	mov	[outfile], esi
   229                                  		; mov (sp),outfile / yes, save arg pointer
   230                                  na2:	
   231 000000EA C7042400000000          	mov	dword [esp], 0
   232                                  		; clr (sp) / clear pointer
   233 000000F1 EB0D                    	jmp	short nch1
   234                                  		; br 3f
   235                                  newchar:
   236 000000F3 3C20                    	cmp	al, 20h
   237                                  		; cmp $' ,r0 / is character a blank
   238 000000F5 7415                    	je	short nch2
   239                                  		; beq 1f / branch if it is (blank as arg separator)
   240 000000F7 3C8D                            cmp     al, 8Dh ; 128 + 13
   241 000000F9 7411                    	je	short nch2
   242                                  		; cmp $'\n+200,r0 / treat \n preceded by 		; beq 1f / as blank
   244                                  nch0:
   245 000000FB E8A0010000              	call	putc
   246                                  		; jsr pc,putc / put this character in parbuf list
   247                                  nch1: ;3:
   248 00000100 E811030000              	call	getc
   249                                  		; jsr pc,getc / get next character
   250 00000105 E8DB020000              	call	delim
   251 0000010A 75E7                    	jne	short newchar
   252                                  	;jz	short nch2 ; '\n', ';', '&'
   253                                  		; jsr	r5,delim / is char a ; \n or &,
   254                                  		;	br 1f / yes
   255                                  	;jmp	short newchar
   256                                  		; br newchar / no, start new character tests
   257                                  nch2: ;1:
   258 0000010C C60600                  	mov	byte [esi], 0
   259 0000010F 46                      	inc	esi
   260                                  		; clrb (r3)+ / end name with \0 when read blank, 
   261                                  			  ; or delim
   262 00000110 5B                      	pop	ebx
   263 00000111 891F                    	mov	[edi], ebx
   264                                  		; mov (sp)+,(r4)+ / move arg ptr to parp location
   265 00000113 09DB                    	or	ebx, ebx
   266 00000115 7403                    	jz	short nch3
   267                                  	;jnz	short nch3
   268                                  		; bne 1f / if (sp)=0, in file or out file points
   269                                  				; to arg
   270 00000117 83C704                  	add	edi, 4
   271                                  		; tst -(r4) / so ignore dummy (0), in pointer list
   272                                  nch3: ;1:
   273 0000011A E8C6020000              	call	delim
   274 0000011F 75A6                    	jne	short newarg
   275                                  	;jz	short nch4 ; '\n', ';', '&'
   276                                  		; jsr r5,delim / is char a ; \n or &.
   277                                  		;     br 2f / yes
   278                                  	;jmp	short newarg
   279                                  		; br newarg / no, start newarg processing
   280                                  nch4: ;2:
   281 00000121 C70700000000            	mov	dword [edi], 0
   282                                  		; clr (r4) / \n, &, or ; takes to here 
   283                                  			 ; / (end of arg list) after 'delim' call
   284 00000127 50                      	push	eax
   285                                  		; mov r0,-(sp) / save delimiter in stack
   286 00000128 E827000000              	call	docom
   287                                  		; jsr pc,docom / go to exec command in parbuf
   288 0000012D 803C2426                	cmp	byte [esp], '&'
   289                                  		; cmpb (sp),$'& / get a new command without wait?
   290                                          ;je	newcom
   291                                  	;	; beq newcom / yes
   292                                  	; 29/05/2022
   293 00000131 7505                    	jne	short nch8
   294                                  nch7:
   295 00000133 E96EFFFFFF              	jmp	newcom
   296                                  nch8:
   297 00000138 21D2                    	and	edx, edx
   298                                  		; tst r1 / was chdir just executed or line ended
   299                                  			; / with ampersand?
   300 0000013A 740D                    	jz	short nch6
   301                                  		; beq 2f / yes
   302                                  nch5: ;1:
   303                                  	sys	_wait
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000013C B807000000          <1>  mov eax, %1
    98 00000141 CD30                <1>  int 30h
   304                                  		; sys wait / no, wait for new process to terminate
   305                                                          ; / command executed)
   306 00000143 7204                    	jc	short nch6
   307                                  		; bcs 2f / no, children not previously waited for
   308 00000145 39D0                    	cmp	eax, edx
   309                                  		; cmp r0,r1 / is this my child
   310 00000147 75F3                    	jne	short nch5
   311                                  		; bne 1b
   312                                  nch6: ;2:
   313 00000149 803C240D                	cmp	byte [esp], 0Dh
   314                                  	;cmp	byte [esp], 0Ah
   315                                  		; cmp (sp),$'\n / was delimiter a new line
   316                                          ;je	newline
   317                                  	;	; beq newline / yes
   318                                  	; 29/05/2022
   319                                  	;jmp	newcom
   320                                  	;	; br newcom / no, pick up next command
   321 0000014D 75E4                    	jne	short nch7 ; jne newcom
   322 0000014F E933FFFFFF              	jmp	newline  ; je newline
   323                                  docom:
   324 00000154 81EF[2A0A0000]          	sub	edi, parp
   325                                  		; sub $parp,r4 / out arg count in r4
   326 0000015A 7503                    	jne	short dcom1
   327                                  		; bne 1f / any arguments?
   328                                  dcom0:
   329 0000015C 29D2                    	sub 	edx, edx ; 0
   330                                  		; clr r1 / no, line ended with ampersand
   331 0000015E C3                      	retn
   332                                  		; rts pc / return from call
   333                                  dcom1: ;1:
   334 0000015F 89FB                    	mov	ebx, edi
   335                                  	; 06/12/2013
   336 00000161 BE[05060000]            	mov	esi, qecho 
   337 00000166 E827010000              	call	chcom
   338 0000016B 7543                    	jnz	short dcom7
   339                                  	; 28/12/2015
   340 0000016D 89DD                    	mov	ebp, ebx
   341 0000016F BF[2A0A0000]            	mov	edi, parp
   342                                  dcom9:  ; CRLF
   343                                  	sys	_write, 1, nextline, 2
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000174 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000179 B9[9D050000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 0000017E BA02000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000183 B804000000          <1>  mov eax, %1
    98 00000188 CD30                <1>  int 30h
   344                                  	;
   345 0000018A 83ED04                  	sub	ebp, 4 ; remain arg count x 4
   346 0000018D 76CD                    	jna	short dcom0
   347 0000018F 83C704                  	add	edi, 4
   348 00000192 8B37                    	mov	esi, [edi]
   349                                  	;or 	esi, esi
   350                                  	;jz	short dcom0
   351 00000194 89F2                    	mov	edx, esi ; string address
   352                                  dcom10:
   353 00000196 AC                      	lodsb
   354 00000197 08C0                    	or 	al, al
   355 00000199 75FB                    	jnz	short dcom10
   356 0000019B 87D6                    	xchg 	edx, esi
   357 0000019D 29F2                    	sub	edx, esi  ; byte count
   358 0000019F 4A                      	dec	edx
   359                                  	;jz	short dcom0
   360                                  	; write string
   361                                  	sys	_write, 1, esi ; edx = byte count
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000001A0 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 000001A5 89F1                <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000001A7 B804000000          <1>  mov eax, %1
    98 000001AC CD30                <1>  int 30h
   362 000001AE EBC4                    	jmp	short dcom9
   363                                  dcom7:
   364 000001B0 BE[0D060000]            	mov	esi, qchdir
   365 000001B5 E8D8000000              	call	chcom
   366 000001BA 752D                    	jnz	short dcom4
   367                                  		; jsr r5,chcom; qchdir / is command chdir?
   368                                  		;     br 2f / command not chdir
   369                                  dcom12:
   370 000001BC 80FB08                  	cmp	bl, 8 ; 8 = arg count x 4 (24/08/2015)
   371                                  	;cmp	bx, 8
   372                                  		; cmp r4,$4 / prepare to exec chdir, 
   373                                  			  ; 4 = arg count x 2
   374 000001BF 740C                    	je	short dcom2
   375                                  		; beq 3f
   376                                  dcom8:
   377 000001C1 BE[B0050000]            	mov	esi, msgArgCount
   378 000001C6 E878000000              	call	error
   379                                  		; jsr r5,error / go to print error
   380                                  		;  	<Arg count\n\0>; .even
   381                                  	;jmp	short dcom3
   382                                  		; br 4f
   383 000001CB EB8F                    	jmp	short dcom0
   384                                  dcom2: ;3:
   385 000001CD 8B1D[2E0A0000]          	mov	ebx, [parp+4]
   386                                  		;mov parp+2,0f / move directory name to sys call
   387                                  	sys	_chdir
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000001D3 B80C000000          <1>  mov eax, %1
    98 000001D8 CD30                <1>  int 30h
   388                                  		; sys chdir; 0:0 / exec chdir
   389 000001DA 730A                    	jnc	short dcom3
   390                                  		; bec 4f / no error exit
   391 000001DC BE[BA050000]            	mov	esi, msgBadDir
   392 000001E1 E85D000000              	call	error
   393                                  		; jsr r5,error / go to print error
   394                                  		; 	<Bad directory\n\0>; .even
   395                                  				; / this diagnostic
   396                                  dcom3: ;4:
   397 000001E6 31D2                    	xor	edx, edx ; 0
   398                                  		; clr r1 / set r1 to zero to skip wait
   399 000001E8 C3                      	retn
   400                                  		; rts pc / and return
   401                                  dcom4: ;2:
   402                                  	; 06/12/2013
   403 000001E9 BE[0A060000]            	mov	esi, qcd
   404 000001EE E89F000000              	call	chcom
   405 000001F3 74C7                    	jz	short dcom12
   406                                  dcom11:
   407 000001F5 BE[13060000]            	mov	esi, glogin
   408 000001FA E893000000              	call	chcom
   409 000001FF 7522                    	jnz	short dcom5
   410                                  		; jsr r5,chcom; glogin / is command login?
   411                                  		;     br 2f / not loqin, go to fork
   412                                  	sys	_exec, parbuf, parp
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000201 BB[30060000]        <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000206 B9[2A0A0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000020B B80B000000          <1>  mov eax, %1
    98 00000210 CD30                <1>  int 30h
   413                                  		; sys exec; parbuf; parp / exec login
   414                                  	sys	_exec, binpb, parp
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000212 BB[2B060000]        <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000217 B9[2A0A0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000021C B80B000000          <1>  mov eax, %1
    98 00000221 CD30                <1>  int 30h
   415                                  		; sys exec; binpb; parp / or /bin/login
   416                                  dcom5: ;2: / no error return??
   417 00000223 BB[D5020000]            	mov	ebx, newproc
   418                                  	; child process will return to 'newproc' address
   419                                  	sys	_fork
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000228 B802000000          <1>  mov eax, %1
    98 0000022D CD30                <1>  int 30h
   420                                  		; sys fork / generate sh child process
   421                                  			 ; for command
   422                                                  ;     br newproc / exec command with 
   423                                  			 ; new process
   424                                  	; parent process will return here
   425 0000022F 730F                    	jnc	short dcom6
   426                                  		; bec 1f / no error exit, old process
   427 00000231 BE[C8050000]            	mov	esi, msgTryAgain
   428 00000236 E808000000              	call	error
   429                                  		; jsr r5,error / go to print error
   430                                  		;     <Try again\n\0>; .even / this diagnostic
   431 0000023B E947FEFFFF                      jmp     newline
   432                                  		; jmp newline / and return for next try
   433                                  dcom6: ;1:
   434 00000240 89C2                    	mov	edx, eax ; child process ID
   435                                  		; mov r0,r1 / save id of child sh
   436 00000242 C3                      	retn
   437                                  		; rts pc / return to "jsr pc, docom" call
   438                                  			; in parent sh
   439                                  error:
   440                                  	sys	_write, 1, nextline, 2
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000243 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000248 B9[9D050000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 0000024D BA02000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000252 B804000000          <1>  mov eax, %1
    98 00000257 CD30                <1>  int 30h
   441                                  s4:
   442 00000259 AC                      	lodsb
   443 0000025A A2[FA0B0000]            	mov	[och], al
   444                                                  ; movb (r5)+,och / pick up diagnostic character
   445 0000025F 20C0                    	and	al, al
   446 00000261 7418                    	jz	short s5
   447                                  		; beq 1f / 0 is end of line
   448                                  	sys	_write, 1, och, 1
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000263 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000268 B9[FA0B0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 0000026D BA01000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000272 B804000000          <1>  mov eax, %1
    98 00000277 CD30                <1>  int 30h
   449                                  		; mov $1,r0 / set for tty output
   450                                  		; sys write; och; 1 / print it
   451 00000279 EBDE                    	jmp	short s4
   452                                  	;jmp	short error
   453                                  		; br error / continue to get characters
   454                                  s5: ;1:
   455                                  	;inc	esi
   456                                  		; inc r5 / inc r5 to point to return
   457                                  	;;and	si, 0FFFEh
   458                                  	;shr	esi, 1
   459                                  	;shl	esi, 1
   460                                  		; bic $1,r5 / make it even
   461                                  	sys	_seek, 0, 0, 2	
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 0000027B BB00000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000280 B900000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 00000285 BA02000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000028A B813000000          <1>  mov eax, %1
    98 0000028F CD30                <1>  int 30h
   462                                  		; clr r0 / set for input
   463                                  		; sys seek; 0; 2 / exit from runcom. skip to
   464                                  			       ; / end of input file
   465 00000291 C3                      	retn
   466                                  		;; rts r5 ; unix v2 shell ; 29/05/2022
   467                                  		;; (not in original unix v1 'sh.s')
   468                                  
   469                                  chcom: ; / has no effect if tty input
   470                                  		; mov (r5)+,r1 / glogin gchdir r1, bump r5
   471 00000292 BF[30060000]            	mov	edi, parbuf
   472                                  		; mov $parbuf,r2 / command address  r2 'login'
   473                                  s6: ;1:
   474 00000297 AC                      	lodsb
   475                                  		; movb (r1)+,r0 / is this command 'chdir'
   476 00000298 AE                      	scasb
   477                                                  ; cmpb (r2)+,r0 / compare command name byte
   478                                                                ; / with 'login' or 'chdir'
   479 00000299 7504                    	jne	short s7
   480                                  		; bne 1f / doesn't compare
   481 0000029B 08C0                    	or	al, al
   482                                  		; tst r0 / is this
   483 0000029D 75F8                    	jnz	short s6
   484                                  		; bne 1b / end of names
   485                                  		; tst (r5)+ / yes, bump r5 again to execute 
   486                                  			; / login or chdir
   487                                  s7: ;1:
   488 0000029F C3                      	retn
   489                                  		; rts r5 / no, return to exec command
   490                                  
   491                                  putc:
   492 000002A0 3C27                    	cmp	al, 27h ; '
   493                                  		; cmp r0,$'' / single quote?
   494 000002A2 740A                    	je	short pch1	
   495                                  		; beq 1f / yes
   496 000002A4 3C22                    	cmp	al, 22h ; "
   497                                  		; cmp r0,$'" / double quote
   498 000002A6 7406                    	je	short pch1
   499                                  		; beq 1f / yes
   500 000002A8 247F                    	and	al, 7Fh
   501                                  		; bic $!177,r0 / no, remove 200, if present
   502 000002AA 8806                    	mov	[esi], al
   503 000002AC 46                      	inc	esi
   504                                  		; movb r0,(r3)+ / store character in parbuf
   505 000002AD C3                      	retn
   506                                  		; rts pc
   507                                  pch1: ;1:
   508 000002AE 50                      	push	eax
   509                                  		; mov r0,-(sp) / push quote mark onto stack
   510                                  pch2: ;1:
   511 000002AF E862010000              	call	getc
   512                                  		; jsr pc,getc / get a quoted character
   513 000002B4 3C0D                    	cmp	al, 0Dh
   514                                  	;cmp	al, 0Ah ; \n
   515                                  		; cmp r0,$'\n / is it end or line
   516 000002B6 750F                    	jne	short pch3
   517                                  		; bne 2f / no
   518 000002B8 BE[D2050000]            	mov	esi, msgImbalance
   519 000002BD E881FFFFFF              	call	error
   520                                  		; jsr r5,error / yes, indicate missing
   521                                  			      ; quote mark
   522                                  		;     <"' imbalance\n\0>; .even
   523 000002C2 E9C0FDFFFF                      jmp     newline
   524                                  		; jmp newline / ask for new line
   525                                  pch3: ;2:
   526 000002C7 380424                  	cmp	[esp], al
   527                                  		; cmp r0,(sp) / is this closing quote mark
   528 000002CA 7407                    	je	short pch4
   529                                  		; beq 1f / yes
   530 000002CC 247F                    	and	al, 7Fh
   531                                  		; bic $!177,r0 / no, strip off 200
   532                                  			      ; if present
   533 000002CE 8806                    	mov	[esi], al
   534 000002D0 46                      	inc	esi
   535                                  		; movb r0,(r3)+ / store quoted character
   536                                  			      ; in parbuf
   537 000002D1 EBDC                    	jmp	short pch2
   538                                  		; br 1b / continue
   539                                  pch4: ;1:
   540 000002D3 58                      	pop	eax
   541                                  		; tst (sp)+ / pop quote mark off stack
   542 000002D4 C3                      	retn
   543                                  		; rts pc / return
   544                                  
   545                                  ; / thp`e new process
   546                                  
   547                                  newproc:
   548 000002D5 8B35[1E0A0000]          	mov	esi, [infile]
   549 000002DB 09F6                    	or	esi, esi
   550 000002DD 7432                    	jz	short np2
   551                                  		; mov infile,0f / move pointer to new file name
   552                                  		; beq 1f / branch if no alternate read file given
   553 000002DF 803E00                  	cmp 	byte [esi], 0
   554                                  		; tstb *0f
   555 000002E2 761C                    	jna	short np1
   556                                  		; beq 3f / branch if no file name given
   557                                  	sys	_close, 0
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000002E4 BB00000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000002E9 B806000000          <1>  mov eax, %1
    98 000002EE CD30                <1>  int 30h
   558                                  		; clr r0 / set tty input file name
   559                                  		; sys close / close it
   560                                  	sys	_open, esi, 0  
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000002F0 89F3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 000002F2 B900000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000002F7 B805000000          <1>  mov eax, %1
    98 000002FC CD30                <1>  int 30h
   561                                  		; sys open; 0:..; 0 / open new input file 
   562                                  				  ; for reading
   563 000002FE 7311                    	jnc	short np2
   564                                  		; bcc 1f / branch if input file ok
   565                                  np1: ;3:
   566 00000300 BE[DF050000]            	mov	esi, msgInputFile
   567 00000305 E839FFFFFF              	call	error
   568                                  		; jsr r5,error / file not ok, print error
   569                                  		;     <Input file\n\0>; .even / this diagnostic
   570                                  	sys	_exit
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000030A B801000000          <1>  mov eax, %1
    98 0000030F CD30                <1>  int 30h
   571                                  		; sys exit / terminate this process 
   572                                  			  ; and make parent sh
   573                                  np2: ;1:
   574 00000311 8B35[220A0000]          	mov	esi, [outfile]
   575                                  		; mov outfile,r2 / more pointer to new file name
   576 00000317 21F6                    	and	esi, esi
   577 00000319 746D                    	jz	short np6
   578                                  		; beq 1f / branch if no alternate write file
   579 0000031B 803E3E                  	cmp	byte [esi], '>'
   580                                  		; cmpb (r2),$'> / is > at beqinning of file name?
   581 0000031E 7511                    	jne	short np3
   582                                  		; bne 4f / branch if it isn't
   583 00000320 46                      	inc	esi
   584                                  		; inc r2 / yes, increment pointer
   585                                  	sys	_open, esi, 1
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000321 89F3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000323 B901000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000328 B805000000          <1>  mov eax, %1
    98 0000032D CD30                <1>  int 30h
   586                                  		; mov r2,0f
   587                                  		; sys open; 0:..; 1 / open file for writing
   588 0000032F 7321                    	jnc	short np5
   589                                  		; bec 3f / if no error
   590                                  np3: ;4:
   591                                  	sys	_creat, esi, 15 ; Decimal 15 = Octal 17
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000331 89F3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000333 B90F000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000338 B808000000          <1>  mov eax, %1
    98 0000033D CD30                <1>  int 30h
   592                                  		; mov r2,0f
   593                                  		; sys creat; 0:..; 17 / create new file 
   594                                  				    ; with this name
   595 0000033F 7311                    	jnc	short np5
   596                                  		; bec 3f / branch if no error
   597                                  np4: ;2:
   598 00000341 BE[EA050000]            	mov	esi, msgOutputFile
   599 00000346 E8F8FEFFFF              	call	error
   600                                  		; jsr r5,error
   601                                  		;     <Output file\n\0>; .even
   602                                  	sys	_exit
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000034B B801000000          <1>  mov eax, %1
    98 00000350 CD30                <1>  int 30h
   603                                  		; sys exit
   604                                  np5: ;3:
   605                                  	sys	_close, eax
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000352 89C3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000354 B806000000          <1>  mov eax, %1
    98 00000359 CD30                <1>  int 30h
   606                                  		; sys close / close the new write file
   607                                  		; mov	r2,0f / move new name to open
   608                                  	sys	_close, 1
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 0000035B BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000360 B806000000          <1>  mov eax, %1
    98 00000365 CD30                <1>  int 30h
   609                                  		; mov $1,r0 / set tty file name
   610                                  		; sys close / close it
   611                                  	sys	_open, esi, 1
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000367 89F3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000369 B901000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000036E B805000000          <1>  mov eax, %1
    98 00000373 CD30                <1>  int 30h
   612                                  		; sys open; 0:..; 1 / open new output file,
   613                                  			      ; /it now has file descriptor 1
   614                                  	sys	_seek, eax, 0, 2
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000375 89C3                <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000377 B900000000          <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93 0000037C BA02000000          <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000381 B813000000          <1>  mov eax, %1
    98 00000386 CD30                <1>  int 30h
   615                                  		; sys seek; 0; 2 / set pointer to 
   616                                  				; current end of file
   617                                  np6: ;1:
   618 00000388 803D[1C0A0000]00        	cmp	byte [glflag], 0
   619                                  		; tst glflag / was *, ? or [ encountered?
   620 0000038F 7739                    	ja	short np9
   621                                  		; bne 1f / yes
   622                                  	sys	_exec, parbuf, parp
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000391 BB[30060000]        <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 00000396 B9[2A0A0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000039B B80B000000          <1>  mov eax, %1
    98 000003A0 CD30                <1>  int 30h
   623                                  		; sys exec; parbuf; parp / no, execute
   624                                  					;  this command
   625                                  	sys	_exec, binpb, parp
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000003A2 BB[2B060000]        <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 000003A7 B9[2A0A0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000003AC B80B000000          <1>  mov eax, %1
    98 000003B1 CD30                <1>  int 30h
   626                                  		; sys exec; binpb; parp / or /bin/this command
   627                                  
   628                                  ;------ 29/05/2022 - unix v2 shell
   629                                  ;	 (source code from disassembled /bin/sh binary)
   630                                  ;	following part is not existing in v2 shell
   631                                  ;
   632                                  ;np7: ;2:
   633                                  ;	sys	_stat, binpb, inbuf
   634                                  ;		; sys stat; binpb; inbuf / if can't execute
   635                                  ;					; / does it exist?
   636                                  ;	jc	short np8
   637                                  ;		; bes 2f / branch if it doesn't
   638                                  ;	mov	esi, parp-4
   639                                  ;	mov	dword [esi], shell
   640                                  ;		; mov $shell,parp-2 / does exist,
   641                                  ;				   ;  not executable
   642                                  ;	mov	eax, binpb
   643                                  ;	mov	[parp], eax
   644                                  ;		; mov $binpb,parp / so it must be
   645                                  ;	sys	_exec, shell, esi 
   646                                  ;		; sys exec; shell; parp-2 / a command file,
   647                                  ;		; / get it with sh /bin/x (if x name of file)
   648                                  ;------
   649                                  
   650                                  np8: ;2:
   651 000003B3 BE[F6050000]            	mov	esi, msgNoCmd
   652 000003B8 E886FEFFFF              	call	error
   653                                  		; jsr r5,error / a return for exec 
   654                                  			       ; is the diagnostic
   655                                  		;     <No command\n\0>; .even
   656 000003BD 8B25[FC0B0000]          	mov	esp, [shellarg]
   657                                  	sys 	_exit
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000003C3 B801000000          <1>  mov eax, %1
    98 000003C8 CD30                <1>  int 30h
   658                                  		; sys exit
   659                                  np9: ;1:
   660 000003CA BE[260A0000]            	mov	esi, parp-4
   661 000003CF C706[21060000]          	mov	dword [esi], glob
   662                                  		; mov $glob,parp-2 / prepare to process *,?
   663                                  	sys	_exec, glob, esi
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000003D5 BB[21060000]        <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 000003DA 89F1                <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000003DC B80B000000          <1>  mov eax, %1
    98 000003E1 CD30                <1>  int 30h
   664                                  		; sys exec; glob; parp-2
   665                                  			    ; / execute modified command
   666 000003E3 EBCE                    	jmp	short np8
   667                                  		; br 2b
   668                                  
   669                                  delim:
   670 000003E5 3C0D                            cmp     al, 0Dh ; carriage return
   671 000003E7 741A                    	je	short dlim2
   672                                  	;cmp	al, 0Ah
   673                                  		; cmp r0,$'\n / is character a newline
   674                                  	;je	short dlim2
   675                                  		; beq 1f
   676 000003E9 3C26                    	cmp	al, '&'
   677                                  		;cmp r0,$'& / is it &
   678 000003EB 7416                    	je	short dlim2
   679                                  		; beq 1f / yes
   680 000003ED 3C3B                    	cmp	al, ';'
   681                                  		; cmp r0,$'; / is it ;
   682 000003EF 7412                    	je	short dlim2
   683                                  		; beq 1f / yes
   684 000003F1 3C3F                    	cmp	al, '?'
   685                                  		; cmp r0,$'? / is it ?
   686 000003F3 7408                    	je	short dlim1
   687                                  		; beq 3f
   688                                  ;
   689                                  ;------ 29/05/2022 - unix v2 shell
   690                                  ;	 (source code from disassembled /bin/sh binary)
   691 000003F5 3C2A                    	cmp	al, '*'
   692                                  		; cmp r0,$'* / is it *
   693 000003F7 7404                    	je	short dlim1
   694                                  		; beq 3f
   695                                  
   696 000003F9 3C5B                    	cmp	al, '['
   697                                  		; cmp r0,$'[ / is it beginning of character string
   698                                  		      ; / (for glob)
   699 000003FB 7506                    	jne	short dlim2
   700                                  		; bne 2f
   701                                  dlim1: ;3:
   702 000003FD FE05[1C0A0000]          	inc	byte [glflag]
   703                                  		; inc glflag / ? or * or [ set flag
   704                                  ;2:
   705                                  	;tst	(r5)+ / bump to process all except \n,;,&
   706                                  dlim2: ;1:
   707                                  	; zf = 1 if the char is '\n' or ';' or '&'
   708 00000403 C3                      	retn
   709                                  		; rts r5
   710                                  blank:
   711 00000404 E80D000000              	call	getc
   712                                  		; jsr pc,getc / get next character
   713 00000409 3C20                    	cmp	al, 20h
   714                                  		; cmp $' ,r0 / leading blanks
   715 0000040B 74F7                    	je	short blank
   716                                  		; beq blank / yes, 'squeeze out'
   717 0000040D 3C8D                    	cmp	al, 8Dh ; 80h + 0Dh
   718                                          ;cmp     al, 8Ah ; 80h + 0Ah
   719 0000040F 74F3                    	je	short blank
   720                                  	        ; cmp r0,$200+'\n / new-line preceded by 				 ;  is translated
   722                                  		; beq blank / into blank
   723                                  	; 28/12/2015
   724 00000411 3C0A                    	cmp	al, 0Ah
   725 00000413 74EF                    	je	short blank
   726                                  	;
   727 00000415 C3                      	retn
   728                                  		; rts pc
   729                                  getc:
   730 00000416 833D[180A0000]00        	cmp	dword [param], 0
   731                                  		; tst param / are we substituting for $n
   732 0000041D 773D                    	ja	short gch3
   733                                  		; bne 2f/ yes
   734                                  gch0:
   735 0000041F 8B1D[F20B0000]                  mov     ebx, [inbufp]
   736                                  		; mov inbufp,r1 / no, move normal input pointer to r1
   737                                  s8:
   738 00000425 3B1D[F60B0000]          	cmp	ebx, [einbuf]
   739                                  		; cmp r1,einbuf / end of input line?
   740 0000042B 7207                    	jb	short gch1
   741                                  		; bne 1f / no
   742 0000042D E877000000              	call	getbuf	
   743                                  		; jsr pc,getbuf / yes, put next console line
   744                                  				;  in buffer
   745 00000432 EBEB                    	jmp	short gch0
   746                                  		; br getc
   747                                  gch1: ;1:
   748 00000434 8A03                    	mov	al, [ebx]
   749 00000436 43                      	inc	ebx
   750                                  		; movb (r1)+,r0 / move byte from input buffer to r0
   751 00000437 891D[F20B0000]          	mov	[inbufp], ebx
   752                                  		; mov r1,inbufp / increment routine
   753 0000043D 0A05[000C0000]          	or	al, [escap]
   754                                  	;or	ax, escap
   755                                  		; bis escap,r0 / if last character was \ this adds
   756                                  		        	; / 200 to current character
   757                                  	;mov	byte [escap], 0
   758                                  	;mov	word [escap], 0
   759                                  		; clr escap / clear, so escap normally zero
   760 00000443 3C5C                    	cmp	al, '\'
   761                                  		; cmp r0,$'\\ / note that \\ is equal \ in as
   762 00000445 740C                    	je	short gch2
   763                                  		; beq 1f
   764 00000447 C605[000C0000]00        	mov	byte [escap], 0
   765 0000044E 3C24                    	cmp	al, '$'
   766                                  		; cmp r0,$'$ / is it $
   767 00000450 7429                    	je	short gch5
   768                                  		; beq 3f / yes
   769 00000452 C3                      	retn
   770                                  		; rts pc / no
   771                                  gch2: ;1:
   772 00000453 C605[000C0000]80                mov     byte [escap], 80h
   773                                  	;mov	word [escap], 128
   774                                  		; mov $200,escap / mark presence of \ in command line
   775 0000045A EBC9                    	jmp	short s8
   776                                  	;jmp	short gch0
   777                                  		; br getc / get next character
   778                                  gch3: ;2:
   779 0000045C 8B1D[180A0000]          	mov	ebx, [param]
   780 00000462 8A03                    	mov	al, [ebx]
   781                                  		; movb *param,r0 / pick up substitution character
   782                                  				; / put in r0
   783 00000464 08C0                    	or	al, al
   784 00000466 7407                    	jz	short gch4
   785                                  		; beq	1f / if end of substitution arg, branch
   786 00000468 FF05[180A0000]          	inc	dword [param]
   787                                  		; inc param / if not end, set for next character
   788 0000046E C3                      	retn
   789                                  		; rts pc / return as though character in ro is normal
   790                                  		       ; / input
   791                                  gch4: ;1:
   792 0000046F C705[180A0000]0000-     	mov	dword [param], 0
   792 00000477 0000               
   793                                  		; clr param / unset substitution pointer
   794 00000479 EBA4                    	jmp	short gch0
   795                                  		; br getc / get next char in normal input
   796                                  gch5: ;3:
   797 0000047B E89FFFFFFF              	call	gch0
   798                                  	;call	getc
   799                                  		; jsr pc,getc / get digit after $
   800 00000480 2C30                    	sub	al, '0'
   801                                  		; sub $'0,r0 / strip off zone bits
   802 00000482 3C09                    	cmp	al, 9
   803                                  		; cmp r0,$9. / compare with digit 9
   804 00000484 7602                    	jna	short gch6 
   805                                  		; blos 1f / less than or equal 9
   806 00000486 B009                    	mov	al, 9
   807                                  		; mov $9.,r0 / if larger than 9, force 9
   808                                  gch6: ;1:
   809 00000488 8B1D[FC0B0000]          	mov	ebx, [shellarg]
   810                                  		; mov shellarg,r1 / get pointer to stack for
   811                                  		           ; / this call of shell
   812 0000048E 0FB6C0                  	movzx 	eax, al	; al->eax
   813 00000491 FEC0                    	inc	al
   814                                  	;inc	eax
   815                                  		; inc r0 / digit +1
   816 00000493 3B03                    	cmp	eax, [ebx]
   817                                  		; cmp r0,(r1) / is it less than # of args 
   818                                  			      ;	in this call
   819 00000495 7388                    	jnb	short gch0
   820                                  		; bge getc / no, ignore it. so this $n is not replaced
   821 00000497 C0E002                  	shl	al, 2 ; multiply by 4 (24/08/2015)
   822                                  	;shl	al, 1
   823                                  	;;shl	ax, 1
   824                                  		; asl r0 / yes, multiply by 2 (to skip words)
   825 0000049A 01C3                    	add	ebx, eax
   826                                  		; add r1,r0 / form pointer to arg pointer (-2)
   827 0000049C 8B4304                  	mov	eax, [ebx+4]
   828 0000049F A3[180A0000]            	mov	[param], eax
   829                                  		; mov 2(r0),param / move arg pointer to param
   830 000004A4 E96DFFFFFF                      jmp     getc
   831                                  		; br getc / go to get substitution arg for $n
   832                                  getbuf:
   833 000004A9 B9[F20A0000]            	mov	ecx, inbuf
   834                                  		; mov $inbuf,r0 / move input buffer address
   835 000004AE 890D[F20B0000]                  mov     [inbufp], ecx
   836                                  		; mov r0,inbufp / to input buffer pointer
   837 000004B4 890D[F60B0000]          	mov	[einbuf], ecx
   838                                  		; mov r0,einbuf / and initialize pointer to end of
   839                                  		         ; / character string
   840 000004BA 49                      	dec	ecx
   841                                  		; dec r0 / decrement pointer so can utilize normal
   842                                  		       ; / 100p starting at 1f
   843                                  		; mov r0,0f / initialize address for reading 1st char
   844 000004BB BA01000000              	mov	edx, 1
   845                                  gbuf0: ;1:
   846 000004C0 41                      	inc	ecx
   847                                  		; inc 0f / this routine filles inbuf with line from
   848                                  		       ; / console - if there is cnc
   849 000004C1 51                      	push	ecx
   850                                  	; edx = 1
   851                                  	sys	_read, 0, och
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 000004C2 BB00000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 000004C7 B9[FA0B0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 000004CC B803000000          <1>  mov eax, %1
    98 000004D1 CD30                <1>  int 30h
   852 000004D3 59                      	pop	ecx
   853                                  	;xor	ebx, ebx ; 0
   854                                  	;sys	_read ; sys _read, ebx, ecx, edx ; ebx = 0, edx = 1
   855                                  		; sys read; 0:0; 1 / read next char into inbuf
   856 000004D4 7254                            jc      xit1
   857                                  		; bcs xit1 / error exit
   858 000004D6 21C0                    	and	eax, eax
   859                                  		; tst r0 / a zero input is end of file
   860 000004D8 7450                            jz      xit1
   861                                  		; beq xit1 / exit
   862 000004DA FF05[F60B0000]          	inc	dword [einbuf]  ; 08/04/2014 (24/08/2015, 32 bit)
   863 000004E0 A0[FA0B0000]            	mov	al, [och]
   864 000004E5 803D[03060000]00        	cmp	byte [_at], 0
   865 000004EC 7608                    	jna	short gbuf1
   866 000004EE 3C08                    	cmp	al, 8 ; backspace
   867 000004F0 746B                    	je	short gbuf3
   868 000004F2 3C7F                    	cmp	al, 127 ; delete
   869 000004F4 7460                    	je	short gbuf6 ; 06/12/2013
   870                                  gbuf1:
   871                                  	;mov	ebx, ecx
   872                                  	;inc	dword [einbuf]
   873                                  		; inc einbuf / eventually einbuf points to \n
   874                                  		       ; / (+1) of this line
   875 000004F6 81F9[F20B0000]          	cmp	ecx, inbuf + 256
   876                                  		; cmp 0b,$inbuf+256. / have we exceeded 
   877                                  				   ; input buffer size
   878 000004FC 732C                            jnb     xit1
   879                                  		; bhis xit1 / if so, exit assume some sort of binary
   880                                  	; 08/04/2014
   881 000004FE 3C0D                    	cmp	al, 0Dh
   882 00000500 752F                    	jne	short gbuf8
   883 00000502 8B1D[F60B0000]          	mov	ebx, [einbuf]
   884 00000508 4B                      	dec	ebx
   885 00000509 8803                    	mov	[ebx], al
   886 0000050B C3                      	retn
   887                                  
   888                                  gbuf2:
   889                                          ; 28/12/2015
   890 0000050C 803D[03060000]00        	cmp	byte [_at], 0
   891 00000513 76AB                            jna     short gbuf0 ; 29/05/2022
   892                                  gbuf7:
   893 00000515 51                      	push	ecx
   894                                  	;mov	[och], al
   895                                  	; edx = 1
   896                                  	sys	_write, 1, och
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88 00000516 BB01000000          <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90 0000051B B9[FA0B0000]        <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 00000520 B804000000          <1>  mov eax, %1
    98 00000525 CD30                <1>  int 30h
   897                                  	;sys	_write, 1, och, 1  ; echo (write char on tty)
   898 00000527 59                      	pop	ecx
   899 00000528 EB96                            jmp     short gbuf0 ; 29/05/2022
   900                                  
   901                                  xit1:	; 29/05/2022
   902                                  	sys	_exit
    84                              <1> 
    85                              <1> 
    86                              <1> 
    87                              <1>  %if %0 >= 2
    88                              <1>  mov ebx, %2
    89                              <1>  %if %0 >= 3
    90                              <1>  mov ecx, %3
    91                              <1> 
    92                              <1>  %if %0 >= 4
    93                              <1>  mov edx, %4
    94                              <1>  %endif
    95                              <1>  %endif
    96                              <1>  %endif
    97 0000052A B801000000          <1>  mov eax, %1
    98 0000052F CD30                <1>  int 30h
   903                                  		; sys exit
   904                                  
   905                                  gbuf8:
   906 00000531 89CB                    	mov	ebx, ecx
   907 00000533 8803                    	mov	[ebx], al
   908                                  	;cmp	al, 0Ah ; \n
   909                                  		; cmpb	*0b,$'\n / end of line?
   910                                  	;je	short  gbuf5
   911                                  	;jne	short gbuf1
   912                                  		; bne 1b / no, go to get next char
   913                                  	;cmp	al, 0Dh ; ENTER
   914                                  	;je	short gbuf5
   915 00000535 803D[03060000]00        	cmp	byte [_at], 0 ; at > 0 --> tty input
   916 0000053C 7682                    	jna	short gbuf0
   917 0000053E 3C1B                    	cmp	al, 1Bh	; ESC
   918 00000540 75CA                    	jne	short gbuf2
   919 00000542 B8[F20A0000]            	mov	eax, inbuf
   920 00000547 A3[F20B0000]            	mov	[inbufp], eax
   921 0000054C A3[F60B0000]            	mov	[einbuf], eax
   922 00000551 E93AFBFFFF                      jmp     nl  ; cancel current command, new line
   923                                  
   924                                  ;gbuf2:
   925                                  ;       ; 28/12/2015
   926                                  ;	cmp	byte [_at], 0
   927                                  ;       jna     gbuf0
   928                                  ;gbuf7:
   929                                  ;	push	ecx
   930                                  ;	;mov	[och], al
   931                                  ;	; edx = 1
   932                                  ;	sys	_write, 1, och
   933                                  ;	;sys	_write, 1, och, 1  ; echo (write char on tty)
   934                                  ;	pop	ecx
   935                                  ;       jmp     gbuf0
   936                                  
   937                                  gbuf6: ; DELETE key -> BACKSPACE key
   938                                  	; mov 	al, 8
   939 00000556 C605[FA0B0000]08        	mov	byte [och], 8 ; 06/12/2013
   940                                  gbuf3:
   941                                  	; 08/04/2014
   942 0000055D FF0D[F60B0000]          	dec	dword [einbuf] ; (24/08/2015, 32 bit code)
   943                                  	; 12/12/2013
   944 00000563 49                      	dec	ecx
   945 00000564 81F9[F20A0000]          	cmp	ecx, inbuf
   946 0000056A 7203                    	jb	short gbuf4
   947 0000056C 49                      	dec 	ecx
   948                                  	; 08/04/2014
   949                                  	;jmp	short gbuf2
   950 0000056D EBA6                    	jmp 	short gbuf7
   951                                  gbuf4:
   952                                  	;mov 	al, 7
   953 0000056F C605[FA0B0000]07        	mov	byte [och], 07h ; beep
   954                                  	; 08/04/2014
   955                                  	;jmp	short gbuf2
   956 00000576 EB9D                    	jmp 	short gbuf7
   957                                  ;gbuf5:
   958                                  ;	retn
   959                                  		; rts pc / yes, return
   960                                  
   961                                  	; 29/05/2022
   962                                  ;xit1:
   963                                  ;	sys	_exit
   964                                  ;		; sys exit
   965                                  
   966                                  ;-----------------------------------------------------------------
   967                                  ;  data - initialized data
   968                                  ;-----------------------------------------------------------------
   969                                  
   970                                  ;  /// Messages
   971                                  
   972 00000578 0D0A                    msg_unix_sh:	db 0Dh, 0Ah
   973 0000057A 526574726F20556E69-     		db 'Retro Unix 386 v1 - shell'
   973 00000583 782033383620763120-
   973 0000058C 2D207368656C6C     
   974                                  		;db 0Dh, 0Ah
   975                                  msgsh_size equ  $ - msg_unix_sh
   976                                  		;db 0
   977 00000593 32392F30352F323032-     		db '29/05/2022'
   977 0000059C 32                 
   978 0000059D 0D0A00                  nextline:	db 0Dh, 0Ah, 0
   979                                  ;Error messages:
   980 000005A0 496E707574206E6F74-     msgNotFound: 	db 'Input not found', 0
   980 000005A9 20666F756E6400     
   981 000005B0 41726720636F756E74-     msgArgCount: 	db 'Arg count',  0
   981 000005B9 00                 
   982 000005BA 426164206469726563-     msgBadDir: 	db 'Bad directory', 0
   982 000005C3 746F727900         
   983 000005C8 54727920616761696E-     msgTryAgain: 	db 'Try again', 0
   983 000005D1 00                 
   984 000005D2 222720696D62616C61-     msgImbalance:   db 22h, 27h, 20h, 'imbalance',  0
   984 000005DB 6E636500           
   985 000005DF 496E7075742066696C-     msgInputFile: 	db 'Input file', 0
   985 000005E8 6500               
   986 000005EA 4F7574707574206669-     msgOutputFile: 	db 'Output file', 0
   986 000005F3 6C6500             
   987 000005F6 4E6F20636F6D6D616E-     msgNoCmd: 	db 'No command',  0
   987 000005FF 6400               
   988                                  
   989                                  ; /// Commands, files, parameters
   990                                  
   991                                  ;quest:
   992                                  	;db '?', 0Dh, 0Ah
   993                                  	;<?\n>
   994                                  
   995                                  prompt:
   996 00000601 0D0A                    	db 0Dh, 0Ah
   997                                  _at:
   998 00000603 4020                    	db '@ '
   999                                  	;<@ >
  1000                                  p_size  equ $ - prompt
  1001                                  
  1002 00000605 6563686F00              qecho: 	db 'echo', 0
  1003                                  ;
  1004 0000060A 636400                  qcd:	db 'cd', 0
  1005                                  ;
  1006                                  qchdir:
  1007 0000060D 636864697200            	db 'chdir', 0
  1008                                  	;<chdir\0>
  1009                                  glogin:
  1010 00000613 6C6F67696E00            	db 'login', 0
  1011                                  	;<login\0>
  1012                                  shell:
  1013 00000619 2F62696E2F736800        	db '/bin/sh', 0
  1014                                  	;</bin/sh\0>
  1015                                  glob:
  1016 00000621 2F6574632F676C6F62-     	db '/etc/glob', 0
  1016 0000062A 00                 
  1017                                  	;</etc/glob\0>
  1018                                  binpb:
  1019 0000062B 2F62696E2F              	db '/bin/'
  1020                                  	;</bin/>
  1021                                  
  1022                                  ;-----------------------------------------------------------------
  1023                                  ;  bss - uninitialized data
  1024                                  ;-----------------------------------------------------------------
  1025                                  
  1026                                  bss_start:
  1027                                  
  1028                                  ABSOLUTE bss_start
  1029                                  
  1030                                  parbuf:
  1031 00000630 <res 3E8h>                      resb 1000
  1032                                   	; .=.+1000.
  1033                                  alignb 2
  1034                                  	;.even
  1035                                  param:
  1036 00000A18 ????????                	resd 1
  1037                                  	;.=.+2
  1038                                  glflag:
  1039 00000A1C ??                      	resb 1
  1040 00000A1D ??                      	resb 1
  1041                                  	;.=.+2
  1042                                  infile:
  1043 00000A1E ????????                	resd 1
  1044                                  	; .=.+2 
  1045                                  outfile:
  1046 00000A22 ????????                	resd 1
  1047                                  	;.=.+2
  1048                                  ; parp-4
  1049 00000A26 ????????                	resd 1
  1050                                  	;.=.+2 / room for glob
  1051                                  parp:
  1052 00000A2A <res C8h>                       resb 200
  1053                                  	;.=.+200.
  1054                                  inbuf:
  1055 00000AF2 <res 100h>                      resb 256
  1056                                  	;.=.+256.
  1057                                  ;escap:
  1058                                  	;resw 1
  1059                                  	;.=.+2
  1060                                  inbufp:
  1061 00000BF2 ????????                	resd 1
  1062                                  	;.=.+2
  1063                                  einbuf:
  1064 00000BF6 ????????                	resd 1
  1065                                  	;.=.+2
  1066                                  och:
  1067 00000BFA ??                      	resb 1
  1068 00000BFB ??                      	resb 1
  1069                                  	;.=.+2
  1070                                  shellarg:
  1071 00000BFC ????????                	resd 1
  1072                                  	;.=.+2
  1073                                  escap:
  1074 00000C00 ??                      	resb 1
  1075                                  	;
  1076 00000C01 ??                      	resb 1
  1077                                  
  1078                                  bss_end:
  1079                                  
  1080                                  ; 29/05/2022
  1081                                  ;-----------------------------------------------------------------
  1082                                  ; Original UNIX v2 - shell - PDP-11 assembly source code (sh.s)
  1083                                  ;-----------------------------------------------------------------
  1084                                  ; UNIX V2 source code: see www.tuhs.org for details.
  1085                                  ;-----------------------------------------------------------------
  1086                                  ; /// Modified unix v1 shell (sh.s) source code by Erdogan Tan /// 
  1087                                  ;-----------------------------------------------------------------
  1088                                  ; s2.tar.gz - \bin\sh 
  1089                                  ;
  1090                                  ; Source code modified via disassembled unix v2 /bin/sh binary file
  1091                                  ; Dissasembler: Hex-Rays Interactive Disassembler (IDA)
  1092                                  ;
  1093                                  ;/ sh -- command interpreter
  1094                                  ;	mov	sp,r5
  1095                                  ;	mov	r5,shellarg / save orig sp in shellarg
  1096                                  ;	cmpb	*2(r5),$'- / was this sh called by init or login
  1097                                  ;	bne	2f / no
  1098                                  ;	sys	intr; 0 / yes, turn off interrupts
  1099                                  ;	sys	quit; 0
  1100                                  ;2:
  1101                                  ;	sys	getuid / who is user
  1102                                  ;	tst	r0 / is it superuser
  1103                                  ;	bne	2f / no
  1104                                  ;	movb	$'#,at / yes, set new prompt symbol
  1105                                  ;2:
  1106                                  ;	cmp	(r5),$1 / tty input?
  1107                                  ;	ble	newline / yes, call with '-(or with no command
  1108                                  ;		        / file name)
  1109                                  ;	clr	r0 / no, set ttv
  1110                                  ;	sys	close / close it
  1111                                  ;	mov	4(r5),0f / get new file name
  1112                                  ;	sys	open; 0:..; 0 / open it
  1113                                  ;	bec	1f / branch if no error
  1114                                  ;	jsr	r5,error / error in file name
  1115                                  ;		<Input not found\n\0>; .even
  1116                                  ;	sys	exit
  1117                                  ;1:
  1118                                  ;	clr	at / clear prompt character, if reading non-tty
  1119                                  ;		   / input file
  1120                                  ;newline:
  1121                                  ;	tst	at / is there a prompt symbol
  1122                                  ;	beq	newcom / no
  1123                                  ;	mov	$1,r0 / yes
  1124                                  ;	sys	write; at; 2. / print prompt
  1125                                  ;newcom:
  1126                                  ;	mov	shellarg,sp /
  1127                                  ;	mov	$parbuf,r3 / initialize command list area
  1128                                  ;	mov	$parp,r4 / initialize command list pointers
  1129                                  ;	clr	infile / initialize alternate input
  1130                                  ;	clr	outfile / initialize alternate output
  1131                                  ;	clr	glflag / initialize global flag
  1132                                  ;newarg:
  1133                                  ;	jsr	pc,blank / squeeze out leading blanks
  1134                                  ;	jsr	r5,delim / is new character a ; \n or &
  1135                                  ;		br 2f / yes
  1136                                  ;	mov	r3,-(sp) / no, push arg pointer onto stack
  1137                                  ;	cmp	r0,$'< / new input file?
  1138                                  ;	bne	1f / no
  1139                                  ;	mov	(sp),infile / yes, save arg pointer
  1140                                  ;	clr	(sp) / clear pointer
  1141                                  ;	br	3f
  1142                                  ;1:
  1143                                  ;	cmp	r0,$'> / new output file?
  1144                                  ;	bne	newchar / no
  1145                                  ;	mov	(sp),outfile / yes, save arg pointer
  1146                                  ;	clr	(sp) / clear pointer
  1147                                  ;	br	3f
  1148                                  ;newchar:
  1149                                  ;	cmp	$' ,r0 / is character a blank
  1150                                  ;	beq	1f / branch if it is (blank as arg separator)
  1151                                  ;	cmp	$'\n+200,r0 / treat \n preceded by ;	beq	1f / as blank
  1153                                  ;	jsr	pc,putc / put this character in parbuf list
  1154                                  ;3:
  1155                                  ;	jsr	pc,getc / get next character
  1156                                  ;	jsr	r5,delim / is char a ; \n or &,
  1157                                  ;		br 1f / yes
  1158                                  ;	br	newchar / no, start new character tests
  1159                                  ;1:
  1160                                  ;	clrb	(r3)+ / end name with \0 when read blank, or
  1161                                  ;		      / delim
  1162                                  ;	mov	(sp)+,(r4)+ / move arg ptr to parp location
  1163                                  ;	bne	1f / if (sp)=0, in file or out file points to arg
  1164                                  ;	tst	-(r4) / so ignore dummy (0), in pointer list
  1165                                  ;1:
  1166                                  ;	jsr	r5,delim / is char a ; \n or &.
  1167                                  ;		br 2f / yes
  1168                                  ;	br	newarg / no, start newarg processing
  1169                                  ;2:
  1170                                  ;	clr	(r4) / \n, &, or ; takes to here (end of arg list)
  1171                                  ;		     / after 'delim' call
  1172                                  ;	mov	r0,-(sp) / save delimiter in stack
  1173                                  ;	jsr	pc,docom / go to exec command in parbuf
  1174                                  ;	cmpb	(sp),$'& / get a new command without wait?
  1175                                  ;	beq	newcom / yes
  1176                                  ;	tst	r1 / was chdir just executed or line ended with
  1177                                  ;		   / ampersand?
  1178                                  ;	beq	2f / yes
  1179                                  ;1:
  1180                                  ;	sys	wait / no, wait for new process to terminate
  1181                                  ;		     / command executed)
  1182                                  ;	bcs	2f / no, children not previously waited for
  1183                                  ;	cmp	r0,r1 / is this my child
  1184                                  ;	bne	1b
  1185                                  ;2:
  1186                                  ;	cmp	(sp),$'\n / was delimiter a new line
  1187                                  ;	beq	newline / yes
  1188                                  ;	br	newcom / no, pick up next command
  1189                                  ;docom:
  1190                                  ;	sub	$parp,r4 / out arg count in r4
  1191                                  ;	bne	1f / any arguments?
  1192                                  ;	clr	r1 / no, line ended with ampersand
  1193                                  ;	rts	pc / return from call
  1194                                  ;1:
  1195                                  ;	jsr	r5,chcom; qchdir / is command chdir?
  1196                                  ;		br 2f / command not chdir
  1197                                  ;	cmp	r4,$4 / prepare to exec chdir, 4=arg count x 2
  1198                                  ;	beq	3f
  1199                                  ;	jsr	r5,error / go to print error
  1200                                  ;		<Arg count\n\0>; .even
  1201                                  ;	br	4f
  1202                                  ;3:
  1203                                  ;	mov	parp+2,0f / more directory name to sys coll
  1204                                  ;	sys	chdir; 0:0 / exec chdir
  1205                                  ;	bec	4f / no error exit
  1206                                  ;	jsr	r5,error / go to print error
  1207                                  ;		<Bad directory\n\0>; .even / this diagnostic
  1208                                  ;4:
  1209                                  ;	clr	r1 / set r1 to zero to dkip wait
  1210                                  ;	rts	pc / and return
  1211                                  ;2:
  1212                                  ;	jsr	r5,chcom; glogin / is command login?
  1213                                  ;		br 2f / not loqin, go to fork
  1214                                  ;	sys	exec; parbuf; parp / exec login
  1215                                  ;	sys	exec; binpb; parp / or /bin/login
  1216                                  ;2: / no error return??
  1217                                  ;	sys	fork / generate sh child process for command
  1218                                  ;		br newproc / exec command with new process
  1219                                  ;	bec	1f / no error exit, old orocess
  1220                                  ;	jsr	r5,error / go to print error
  1221                                  ;		<Try again\n\0>; .even / this diaonostic
  1222                                  ;	jmp	newline / and return for next try
  1223                                  ;1:
  1224                                  ;	mov	r0,r1 / save id of child sh
  1225                                  ;	rts	pc / return to "jsr pc, docom" call in parent sh
  1226                                  ;
  1227                                  ;error:
  1228                                  ;	movb	(r5)+,och / pick up diagnostic character
  1229                                  ;	beq	1f / 0 is end of line
  1230                                  ;	mov	$1,r0 / set for tty output
  1231                                  ;	sys	write; och; 1 / print it
  1232                                  ;	br	error / continue to get characters
  1233                                  ;1:
  1234                                  ;	inc	r5 / inc r5 to point to return
  1235                                  ;	bic	$1,r5 / make it even
  1236                                  ;	clr	r0 / set for input
  1237                                  ;	sys	seek; 0; 2 / exit from runcom. skip to end of
  1238                                  ;		           / input file
  1239                                  ;
  1240                                  ;/------ 29/05/2022 - unix v2 shell
  1241                                  ;/	 (source code from disassembled /bin/sh binary)
  1242                                  ;	rts	r5
  1243                                  ;
  1244                                  ;chcom: / has no effect if tty input
  1245                                  ;	mov	(r5)+,r1 / glogin gchdir r1, bump r5
  1246                                  ;	mov	$parbuf,r2 / command address  r2 'login'
  1247                                  ;1:
  1248                                  ;	movb	 (r1)+,r0 / is this command 'chdir'
  1249                                  ;	cmpb	(r2)+,r0 / compare command name byte with 'login'
  1250                                  ;		         / or 'chdir'
  1251                                  ;	bne	1f / doesn't compare
  1252                                  ;	tst	r0 / is this
  1253                                  ;	bne	1b / end of names
  1254                                  ;	tst	(r5)+ / yes, bump r5 again to execute login
  1255                                  ;		      / chdir
  1256                                  ;1:
  1257                                  ;	rts	r5 / no, return to exec command
  1258                                  ;
  1259                                  ;putc:
  1260                                  ;	cmp	r0,$'' / single quote?
  1261                                  ;	beq	1f / yes
  1262                                  ;	cmp	r0,$'" / double quote
  1263                                  ;	beq	1f / yes
  1264                                  ;	bic	$!177,r0 / no, remove 200, if present
  1265                                  ;	movb	r0,(r3)+ / store character in parbuf
  1266                                  ;	rts	pc
  1267                                  ;1:
  1268                                  ;	mov	r0,-(sp) / push quote mark onto stack
  1269                                  ;1:
  1270                                  ;	jsr	pc,getc / get a quoted character
  1271                                  ;	cmp	r0,$'\n / is it end or line
  1272                                  ;	bne	2f / no
  1273                                  ;	jsr	r5,error / yes, indicate missing quote mark
  1274                                  ;		<"' imbalance\n\0>; .even
  1275                                  ;	jmp	newline / ask for new line
  1276                                  ;2:
  1277                                  ;	cmp	r0,(sp) / is this closing quote mark
  1278                                  ;	beq	1f / yes
  1279                                  ;	bic	$!177,r0 / no, strip off 200 if present
  1280                                  ;	movb	r0,(r3)+ / store quoted character in parbuf
  1281                                  ;	br	1b / continue
  1282                                  ;1:
  1283                                  ;	tst	(sp)+ / pop quote mark off stack
  1284                                  ;	rts	pc / return
  1285                                  ;
  1286                                  ;/ thp`e new process
  1287                                  ;
  1288                                  ;newproc:
  1289                                  ;	mov	infile,0f / move pointer to new file name
  1290                                  ;	beq	1f / branch if no alternate read file given
  1291                                  ;	tstb	*0f
  1292                                  ;	beq	3f / branch if no file name miven
  1293                                  ;	clr	r0 / set tty input file name
  1294                                  ;	sys	close / close it
  1295                                  ;	sys	open; 0:..; 0 / open new input file for reading
  1296                                  ;	bcc	1f / branch if input file ok
  1297                                  ;3:
  1298                                  ;	jsr	r5,error / file not ok, print error
  1299                                  ;		<Input file\n\0>; .even / this diagnostic
  1300                                  ;	sys	exit / terminate this process and make parent sh
  1301                                  ;1:
  1302                                  ;	mov	outfile,r2 / more pointer to new file name
  1303                                  ;	beq	1f / branch if no alternate write file
  1304                                  ;	cmpb	(r2),$'> / is > at beqinning of file name?
  1305                                  ;	bne	4f / branch if it isn't
  1306                                  ;	inc	r2 / yes, increment pointer
  1307                                  ;	mov	r2,0f
  1308                                  ;	sys	open; 0:..; 1 / open file for writing
  1309                                  ;	bec	3f / if no error
  1310                                  ;4:
  1311                                  ;	mov	r2,0f
  1312                                  ;	sys	creat; 0:..; 17 / create new file with this name
  1313                                  ;	bec	3f / branch if no error
  1314                                  ;2:
  1315                                  ;	jsr	r5,error
  1316                                  ;		<Output file\n\0>; .even
  1317                                  ;	sys	exit
  1318                                  ;3:
  1319                                  ;	sys	close / close the new write file
  1320                                  ;	mov	r2,0f / move new name to open
  1321                                  ;	mov	$1,r0 / set ttv file name
  1322                                  ;	sys	close / close it
  1323                                  ;	sys	open; 0:..; 1 / open new output file, it now has
  1324                                  ;		              / file descriptor 1
  1325                                  ;	sys	seek; 0; 2 / set pointer to current end of file
  1326                                  ;1:
  1327                                  ;	tst	glflag / was *, ? or [ encountered?
  1328                                  ;	bne	1f / yes
  1329                                  ;	sys	exec; parbuf; parp / no, execute this commend
  1330                                  ;	sys	exec; binpb; parp / or /bin/this command
  1331                                  ;
  1332                                  ;/------ 29/05/2022 - unix v2 shell
  1333                                  ;/	 (source code from disassembled /bin/sh binary)
  1334                                  ;/	following part is not existing in v2 shell
  1335                                  ;
  1336                                  ;/2:
  1337                                  ;/	sys	stat; binpb; inbuf / if can't execute does it
  1338                                  ;/		                   / exist?
  1339                                  ;/	bes	2f / branch if it doesn't
  1340                                  ;/	mov	$shell,parp-2 / does exist, not executable
  1341                                  ;/	mov	$binpb,parp / so it must be
  1342                                  ;/	sys	exec; shell; parp-2 / a command file, get it with
  1343                                  ;/		                    / sh /bin/x (if x name of file)
  1344                                  ;/------
  1345                                  ;2:
  1346                                  ;	jsr	r5,error / a return for exec is the diagnostic
  1347                                  ;		<No command\n\0>; .even
  1348                                  ;	sys	exit
  1349                                  ;1:
  1350                                  ;	mov	$glob,parp-2 / prepare to process *,?
  1351                                  ;	sys	exec; glob; parp-2 / execute modified command
  1352                                  ;	br	2b
  1353                                  ;
  1354                                  ;delim:
  1355                                  ;	cmp	r0,$'\n / is character a newline
  1356                                  ;	beq	1f
  1357                                  ;	cmp	r0,$'& / is it &
  1358                                  ;	beq	1f / yes
  1359                                  ;	cmp	r0,$'; / is it ;
  1360                                  ;	beq	1f / yes
  1361                                  ;	cmp	r0,$'? / is it ?
  1362                                  ;	beq	3f
  1363                                  ;
  1364                                  ;/------ 29/05/2022 - unix v2 shell
  1365                                  ;/	 (source code from disassembled /bin/sh binary)
  1366                                  ;	cmp	r0,$'* / is it *
  1367                                  ;	beq	3f
  1368                                  ;
  1369                                  ;	cmp	r0,$'[ / is it beginning of character string
  1370                                  ;		       / (for glob)
  1371                                  ;	bne	2f
  1372                                  ;3:
  1373                                  ;	inc	glflag / ? or * or [ set flag
  1374                                  ;2:
  1375                                  ;	tst	(r5)+ / bump to process all except \n,;,&
  1376                                  ;1:
  1377                                  ;	rts	r5
  1378                                  ;
  1379                                  ;blank:
  1380                                  ;	jsr	pc,getc / get next character
  1381                                  ;	cmp	$' ,r0 / leading blanks
  1382                                  ;	beq	blank / yes, 'squeeze out'
  1383                                  ;	cmp	r0,$200+'\n / new-line preceded by \ is translated
  1384                                  ;	beq	blank / into blank
  1385                                  ;	rts	pc
  1386                                  ;getc:
  1387                                  ;	tst	param / are we substituting for $n
  1388                                  ;	bne	2f/ yes
  1389                                  ;	mov	inbufp,r1 / no, move normal input pointer to r1
  1390                                  ;	cmp	r1,einbuf / end of input line?
  1391                                  ;	bne	1f / no
  1392                                  ;	jsr	pc,getbuf / yes, put next console line in buffer
  1393                                  ;	br	getc
  1394                                  ;1:
  1395                                  ;	movb	(r1)+,r0 / move byte from input buffer to r0
  1396                                  ;	mov	r1,inbufp / increment routine
  1397                                  ;	bis	escap,r0 / if last character was \ this adds
  1398                                  ;		         / 200 to current character
  1399                                  ;	clr	escap / clear, so escap normally zero
  1400                                  ;	cmp	r0,$'\\ / note that \\ is equal \ in as
  1401                                  ;	beq	1f
  1402                                  ;	cmp	r0,$'$ / is it $
  1403                                  ;	beq	3f / yes
  1404                                  ;	rts	pc / no
  1405                                  ;1:
  1406                                  ;	mov	$200,escap / mark presence of \ in command line
  1407                                  ;	br	getc / get next character
  1408                                  ;2:
  1409                                  ;	movb	*param,r0 / pick up substitution character put in
  1410                                  ;		          / r0
  1411                                  ;	beq	1f / if end of substitution arg, branch
  1412                                  ;	inc	param / if not end, set for next character
  1413                                  ;	rts	pc / return as though character in ro is normal
  1414                                  ;		   / input
  1415                                  ;1:
  1416                                  ;	clr	param / unset substitution pointer
  1417                                  ;	br	getc / get next char in normal input
  1418                                  ;3:
  1419                                  ;	jsr	pc,getc / get digit after $
  1420                                  ;	sub	$'0,r0 / strip off zone bits
  1421                                  ;	cmp	r0,$9. / compare with digit 9 
  1422                                  ;	blos	1f / less than or equal 9
  1423                                  ;	mov	$9.,r0 / if larger than 9, force 9
  1424                                  ;1:
  1425                                  ;	mov	shellarg,r1 / get pointer to stack for
  1426                                  ;		            / this call of shell
  1427                                  ;	inc	r0 / digit +1
  1428                                  ;	cmp	r0,(r1) / is it less than # of args in this call
  1429                                  ;	bge	getc / no, ignore it. so this $n is not replaced
  1430                                  ;	asl	r0 / yes, multiply by 2 (to skip words)
  1431                                  ;	add	r1,r0 / form pointer to arg pointer (-2)
  1432                                  ;	mov	2(r0),param / move arg pointer to param
  1433                                  ;	br	getc / go to get substitution arg for $n
  1434                                  ;getbuf:
  1435                                  ;	mov	$inbuf,r0 / move input buffer address
  1436                                  ;	mov	r0,inbufp / to input buffer pointer
  1437                                  ;	mov	r0,einbuf / and initialize pointer to end of
  1438                                  ;		          / character string
  1439                                  ;	dec	r0 / decrement pointer so can utilize normal
  1440                                  ;		   / 100p starting at 1f
  1441                                  ;	mov	r0,0f / initialize address for reading 1st char
  1442                                  ;1:
  1443                                  ;	inc	0f / this routine filles inbuf with line from
  1444                                  ;		   / console - if there is cnc
  1445                                  ;	clr	r0 / set for tty input
  1446                                  ;	sys	read; 0:0; 1 / read next char into inbuf
  1447                                  ;	bcs	xit1 / error exit
  1448                                  ;	tst	r0 / a zero input is end of file
  1449                                  ;	beq	xit1 / exit
  1450                                  ;	inc	einbuf / eventually einbuf points to \n
  1451                                  ;		       / (+1) of this line
  1452                                  ;	cmp	0b,$inbuf+256. / have we exceeded input buffer size
  1453                                  ;	bhis	xit1 / if so, exit assume some sort of binary
  1454                                  ;	cmpb	*0b,$'\n / end of line?
  1455                                  ;	bne	1b / no, go to get next char
  1456                                  ;	rts	pc / yes, return
  1457                                  ;
  1458                                  ;xit1:
  1459                                  ;	sys	exit
  1460                                  ;
  1461                                  ;quest:
  1462                                  ;	<?\n>
  1463                                  ;
  1464                                  ;at:
  1465                                  ;	<@ >
  1466                                  ;
  1467                                  ;qchdir:
  1468                                  ;	<chdir\0>
  1469                                  ;glogin:
  1470                                  ;	<login\0>
  1471                                  ;shell:
  1472                                  ;	</bin/sh\0>
  1473                                  ;glob:
  1474                                  ;	</etc/glob\0>
  1475                                  ;binpb:
  1476                                  ;	</bin/>
  1477                                  ;parbuf: .=.+1000.
  1478                                  ;	.even
  1479                                  ;param:	.=.+2
  1480                                  ;glflag: .=.+2
  1481                                  ;infile: .=.+2 
  1482                                  ;outfile:.=.+2
  1483                                  ;	.=.+2 / room for glob
  1484                                  ;parp:	.=.+200.
  1485                                  ;inbuf:	.=.+256.
  1486                                  ;escap:	.=.+2
  1487                                  ;inbufp: .=.+2
  1488                                  ;einbuf: .=.+2
  1489                                  ;och:	.=.+2
  1490                                  ;shellarg:.=.+2
  1491                                  
  1492                                  ; 29/05/2022
  1493                                  ;-----------------------------------------------------------------
  1494                                  ; Original UNIX v1 - shell - PDP-11 assembly source code (sh.s)
  1495                                  ;-----------------------------------------------------------------
  1496                                  ; UNIX V1 source code: see www.tuhs.org for details.
  1497                                  ;-----------------------------------------------------------------
  1498                                  ; PreliminaryUnixImplementationDocument_Jun72.pdf - Section: E11
  1499                                  ;-----------------------------------------------------------------
  1500                                  ; https://minnie.tuhs.org/cgi-bin/utree.pl?file=V1/sh.s
  1501                                  ;
  1502                                  ;/ sh -- command interpreter
  1503                                  ;	mov	sp,r5
  1504                                  ;	mov	r5,shellarg / save orig sp in shellarg
  1505                                  ;	cmpb	*2(r5),$'- / was this sh called by init or login
  1506                                  ;	bne	2f / no
  1507                                  ;	sys	intr; 0 / yes, turn off interrupts
  1508                                  ;	sys	quit; 0
  1509                                  ;2:
  1510                                  ;	sys	getuid / who is user
  1511                                  ;	tst	r0 / is it superuser
  1512                                  ;	bne	2f / no
  1513                                  ;	movb	$'#,at / yes, set new prompt symbol
  1514                                  ;2:
  1515                                  ;	cmp	(r5),$1 / tty input?
  1516                                  ;	ble	newline / yes, call with '-(or with no command
  1517                                  ;		        / file name)
  1518                                  ;	clr	r0 / no, set ttv
  1519                                  ;	sys	close / close it
  1520                                  ;	mov	4(r5),0f / get new file name
  1521                                  ;	sys	open; 0:..; 0 / open it
  1522                                  ;	bec	1f / branch if no error
  1523                                  ;	jsr	r5,error / error in file name
  1524                                  ;		<Input not found\n\0>; .even
  1525                                  ;	sys	exit
  1526                                  ;1:
  1527                                  ;	clr	at / clear prompt character, if reading non-tty
  1528                                  ;		   / input file
  1529                                  ;newline:
  1530                                  ;	tst	at / is there a prompt symbol
  1531                                  ;	beq	newcom / no
  1532                                  ;	mov	$1,r0 / yes
  1533                                  ;	sys	write; at; 2. / print prompt
  1534                                  ;newcom:
  1535                                  ;	mov	shellarg,sp /
  1536                                  ;	mov	$parbuf,r3 / initialize command list area
  1537                                  ;	mov	$parp,r4 / initialize command list pointers
  1538                                  ;	clr	infile / initialize alternate input
  1539                                  ;	clr	outfile / initialize alternate output
  1540                                  ;	clr	glflag / initialize global flag
  1541                                  ;newarg:
  1542                                  ;	jsr	pc,blank / squeeze out leading blanks
  1543                                  ;	jsr	r5,delim / is new character a ; \n or &
  1544                                  ;		br 2f / yes
  1545                                  ;	mov	r3,-(sp) / no, push arg pointer onto stack
  1546                                  ;	cmp	r0,$'< / new input file?
  1547                                  ;	bne	1f / no
  1548                                  ;	mov	(sp),infile / yes, save arg pointer
  1549                                  ;	clr	(sp) / clear pointer
  1550                                  ;	br	3f
  1551                                  ;1:
  1552                                  ;	cmp	r0,$'> / new output file?
  1553                                  ;	bne	newchar / no
  1554                                  ;	mov	(sp),outfile / yes, save arg pointer
  1555                                  ;	clr	(sp) / clear pointer
  1556                                  ;	br	3f
  1557                                  ;newchar:
  1558                                  ;	cmp	$' ,r0 / is character a blank
  1559                                  ;	beq	1f / branch if it is (blank as arg separator)
  1560                                  ;	cmp	$'\n+200,r0 / treat \n preceded by ;	beq	1f / as blank
  1562                                  ;	jsr	pc,putc / put this character in parbuf list
  1563                                  ;3:
  1564                                  ;	jsr	pc,getc / get next character
  1565                                  ;	jsr	r5,delim / is char a ; \n or &,
  1566                                  ;		br 1f / yes
  1567                                  ;	br	newchar / no, start new character tests
  1568                                  ;1:
  1569                                  ;	clrb	(r3)+ / end name with \0 when read blank, or
  1570                                  ;		      / delim
  1571                                  ;	mov	(sp)+,(r4)+ / move arg ptr to parp location
  1572                                  ;	bne	1f / if (sp)=0, in file or out file points to arg
  1573                                  ;	tst	-(r4) / so ignore dummy (0), in pointer list
  1574                                  ;1:
  1575                                  ;	jsr	r5,delim / is char a ; \n or &.
  1576                                  ;		br 2f / yes
  1577                                  ;	br	newarg / no, start newarg processing
  1578                                  ;2:
  1579                                  ;	clr	(r4) / \n, &, or ; takes to here (end of arg list)
  1580                                  ;		     / after 'delim' call
  1581                                  ;	mov	r0,-(sp) / save delimiter in stack
  1582                                  ;	jsr	pc,docom / go to exec command in parbuf
  1583                                  ;	cmpb	(sp),$'& / get a new command without wait?
  1584                                  ;	beq	newcom / yes
  1585                                  ;	tst	r1 / was chdir just executed or line ended with
  1586                                  ;		   / ampersand?
  1587                                  ;	beq	2f / yes
  1588                                  ;1:
  1589                                  ;	sys	wait / no, wait for new process to terminate
  1590                                  ;		     / command executed)
  1591                                  ;	bcs	2f / no, children not previously waited for
  1592                                  ;	cmp	r0,r1 / is this my child
  1593                                  ;	bne	1b
  1594                                  ;2:
  1595                                  ;	cmp	(sp),$'\n / was delimiter a new line
  1596                                  ;	beq	newline / yes
  1597                                  ;	br	newcom / no, pick up next command
  1598                                  ;docom:
  1599                                  ;	sub	$parp,r4 / out arg count in r4
  1600                                  ;	bne	1f / any arguments?
  1601                                  ;	clr	r1 / no, line ended with ampersand
  1602                                  ;	rts	pc / return from call
  1603                                  ;1:
  1604                                  ;	jsr	r5,chcom; qchdir / is command chdir?
  1605                                  ;		br 2f / command not chdir
  1606                                  ;	cmp	r4,$4 / prepare to exec chdir, 4=arg count x 2
  1607                                  ;	beq	3f
  1608                                  ;	jsr	r5,error / go to print error
  1609                                  ;		<Arg count\n\0>; .even
  1610                                  ;	br	4f
  1611                                  ;3:
  1612                                  ;	mov	parp+2,0f / more directory name to sys coll
  1613                                  ;	sys	chdir; 0:0 / exec chdir
  1614                                  ;	bec	4f / no error exit
  1615                                  ;	jsr	r5,error / go to print error
  1616                                  ;		<Bad directory\n\0>; .even / this diagnostic
  1617                                  ;4:
  1618                                  ;	clr	r1 / set r1 to zero to dkip wait
  1619                                  ;	rts	pc / and return
  1620                                  ;2:
  1621                                  ;	jsr	r5,chcom; glogin / is command login?
  1622                                  ;		br 2f / not loqin, go to fork
  1623                                  ;	sys	exec; parbuf; parp / exec login
  1624                                  ;	sys	exec; binpb; parp / or /bin/login
  1625                                  ;2: / no error return??
  1626                                  ;	sys	fork / generate sh child process for command
  1627                                  ;		br newproc / exec command with new process
  1628                                  ;	bec	1f / no error exit, old orocess
  1629                                  ;	jsr	r5,error / go to print error
  1630                                  ;		<Try again\n\0>; .even / this diaonostic
  1631                                  ;	jmp	newline / and return for next try
  1632                                  ;1:
  1633                                  ;	mov	r0,r1 / save id of child sh
  1634                                  ;	rts	pc / return to "jsr pc, docom" call in parent sh
  1635                                  ;
  1636                                  ;error:
  1637                                  ;	movb	(r5)+,och / pick up diagnostic character
  1638                                  ;	beq	1f / 0 is end of line
  1639                                  ;	mov	$1,r0 / set for tty output
  1640                                  ;	sys	write; och; 1 / print it
  1641                                  ;	br	error / continue to get characters
  1642                                  ;1:
  1643                                  ;	inc	r5 / inc r5 to point to return
  1644                                  ;	bic	$1,r5 / make it even
  1645                                  ;	clr	r0 / set for input
  1646                                  ;	sys	seek; 0; 2 / exit from runcom. skip to end of
  1647                                  ;		           / input file
  1648                                  ;chcom: / has no effect if tty input
  1649                                  ;	mov	(r5)+,r1 / glogin gchdir r1, bump r5
  1650                                  ;	mov	$parbuf,r2 / command address  r2 'login'
  1651                                  ;1:
  1652                                  ;	movb	 (r1)+,r0 / is this command 'chdir'
  1653                                  ;	cmpb	(r2)+,r0 / compare command name byte with 'login'
  1654                                  ;		         / or 'chdir'
  1655                                  ;	bne	1f / doesn't compare
  1656                                  ;	tst	r0 / is this
  1657                                  ;	bne	1b / end of names
  1658                                  ;	tst	(r5)+ / yes, bump r5 again to execute login
  1659                                  ;		      / chdir
  1660                                  ;1:
  1661                                  ;	rts	r5 / no, return to exec command
  1662                                  ;
  1663                                  ;putc:
  1664                                  ;	cmp	r0,$'' / single quote?
  1665                                  ;	beq	1f / yes
  1666                                  ;	cmp	r0,$'" / double quote
  1667                                  ;	beq	1f / yes
  1668                                  ;	bic	$!177,r0 / no, remove 200, if present
  1669                                  ;	movb	r0,(r3)+ / store character in parbuf
  1670                                  ;	rts	pc
  1671                                  ;1:
  1672                                  ;	mov	r0,-(sp) / push quote mark onto stack
  1673                                  ;1:
  1674                                  ;	jsr	pc,getc / get a quoted character
  1675                                  ;	cmp	r0,$'\n / is it end or line
  1676                                  ;	bne	2f / no
  1677                                  ;	jsr	r5,error / yes, indicate missing quote mark
  1678                                  ;		<"' imbalance\n\0>; .even
  1679                                  ;	jmp	newline / ask for new line
  1680                                  ;2:
  1681                                  ;	cmp	r0,(sp) / is this closing quote mark
  1682                                  ;	beq	1f / yes
  1683                                  ;	bic	$!177,r0 / no, strip off 200 if present
  1684                                  ;	movb	r0,(r3)+ / store quoted character in parbuf
  1685                                  ;	br	1b / continue
  1686                                  ;1:
  1687                                  ;	tst	(sp)+ / pop quote mark off stack
  1688                                  ;	rts	pc / return
  1689                                  ;
  1690                                  ;/ thp`e new process
  1691                                  ;
  1692                                  ;newproc:
  1693                                  ;	mov	infile,0f / move pointer to new file name
  1694                                  ;	beq	1f / branch if no alternate read file given
  1695                                  ;	tstb	*0f
  1696                                  ;	beq	3f / branch if no file name miven
  1697                                  ;	clr	r0 / set tty input file name
  1698                                  ;	sys	close / close it
  1699                                  ;	sys	open; 0:..; 0 / open new input file for reading
  1700                                  ;	bcc	1f / branch if input file ok
  1701                                  ;3:
  1702                                  ;	jsr	r5,error / file not ok, print error
  1703                                  ;		<Input file\n\0>; .even / this diagnostic
  1704                                  ;	sys	exit / terminate this process and make parent sh
  1705                                  ;1:
  1706                                  ;	mov	outfile,r2 / more pointer to new file name
  1707                                  ;	beq	1f / branch if no alternate write file
  1708                                  ;	cmpb	(r2),$'> / is > at beqinning of file name?
  1709                                  ;	bne	4f / branch if it isn't
  1710                                  ;	inc	r2 / yes, increment pointer
  1711                                  ;	mov	r2,0f
  1712                                  ;	sys	open; 0:..; 1 / open file for writing
  1713                                  ;	bec	3f / if no error
  1714                                  ;4:
  1715                                  ;	mov	r2,0f
  1716                                  ;	sys	creat; 0:..; 17 / create new file with this name
  1717                                  ;	bec	3f / branch if no error
  1718                                  ;2:
  1719                                  ;	jsr	r5,error
  1720                                  ;		<Output file\n\0>; .even
  1721                                  ;	sys	exit
  1722                                  ;3:
  1723                                  ;	sys	close / close the new write file
  1724                                  ;	mov	r2,0f / move new name to open
  1725                                  ;	mov	$1,r0 / set ttv file name
  1726                                  ;	sys	close / close it
  1727                                  ;	sys	open; 0:..; 1 / open new output file, it now has
  1728                                  ;		              / file descriptor 1
  1729                                  ;	sys	seek; 0; 2 / set pointer to current end of file
  1730                                  ;1:
  1731                                  ;	tst	glflag / was *, ? or [ encountered?
  1732                                  ;	bne	1f / yes
  1733                                  ;	sys	exec; parbuf; parp / no, execute this commend
  1734                                  ;	sys	exec; binpb; parp / or /bin/this command
  1735                                  ;2:
  1736                                  ;	sys	stat; binpb; inbuf / if can't execute does it
  1737                                  ;		                   / exist?
  1738                                  ;	bes	2f / branch if it doesn't
  1739                                  ;	mov	$shell,parp-2 / does exist, not executable
  1740                                  ;	mov	$binpb,parp / so it must be
  1741                                  ;	sys	exec; shell; parp-2 / a command file, get it with
  1742                                  ;		                    / sh /bin/x (if x name of file)
  1743                                  ;2:
  1744                                  ;	jsr	r5,error / a return for exec is the diagnostic
  1745                                  ;		<No command\n\0>; .even
  1746                                  ;	sys	exit
  1747                                  ;1:
  1748                                  ;	mov	$glob,parp-2 / prepare to process *,?
  1749                                  ;	sys	exec; glob; parp-2 / execute modified command
  1750                                  ;	br	2b
  1751                                  ;
  1752                                  ;delim:
  1753                                  ;	cmp	r0,$'\n / is character a newline
  1754                                  ;	beq	1f
  1755                                  ;	cmp	r0,$'& / is it &
  1756                                  ;	beq	1f / yes
  1757                                  ;	cmp	r0,$'; / is it ;
  1758                                  ;	beq	1f / yes
  1759                                  ;	cmp	r0,$'? / is it ?
  1760                                  ;	beq	3f
  1761                                  ;	cmp	r0,$'[ / is it beginning of character string
  1762                                  ;		       / (for glob)
  1763                                  ;	bne	2f
  1764                                  ;3:
  1765                                  ;	inc	glflag / ? or * or [ set flag
  1766                                  ;2:
  1767                                  ;	tst	(r5)+ / bump to process all except \n,;,&
  1768                                  ;1:
  1769                                  ;	rts	r5
  1770                                  ;
  1771                                  ;blank:
  1772                                  ;	jsr	pc,getc / get next character
  1773                                  ;	cmp	$' ,r0 / leading blanks
  1774                                  ;	beq	blank / yes, 'squeeze out'
  1775                                  ;	cmp	r0,$200+'\n / new-line preceded by \ is translated
  1776                                  ;	beq	blank / into blank
  1777                                  ;	rts	pc
  1778                                  ;getc:
  1779                                  ;	tst	param / are we substituting for $n
  1780                                  ;	bne	2f/ yes
  1781                                  ;	mov	inbufp,r1 / no, move normal input pointer to r1
  1782                                  ;	cmp	r1,einbuf / end of input line?
  1783                                  ;	bne	1f / no
  1784                                  ;	jsr	pc,getbuf / yes, put next console line in buffer
  1785                                  ;	br	getc
  1786                                  ;1:
  1787                                  ;	movb	(r1)+,r0 / move byte from input buffer to r0
  1788                                  ;	mov	r1,inbufp / increment routine
  1789                                  ;	bis	escap,r0 / if last character was \ this adds
  1790                                  ;		         / 200 to current character
  1791                                  ;	clr	escap / clear, so escap normally zero
  1792                                  ;	cmp	r0,$'\\ / note that \\ is equal \ in as
  1793                                  ;	beq	1f
  1794                                  ;	cmp	r0,$'$ / is it $
  1795                                  ;	beq	3f / yes
  1796                                  ;	rts	pc / no
  1797                                  ;1:
  1798                                  ;	mov	$200,escap / mark presence of \ in command line
  1799                                  ;	br	getc / get next character
  1800                                  ;2:
  1801                                  ;	movb	*param,r0 / pick up substitution character put in
  1802                                  ;		          / r0
  1803                                  ;	beq	1f / if end of substitution arg, branch
  1804                                  ;	inc	param / if not end, set for next character
  1805                                  ;	rts	pc / return as though character in ro is normal
  1806                                  ;		   / input
  1807                                  ;1:
  1808                                  ;	clr	param / unset substitution pointer
  1809                                  ;	br	getc / get next char in normal input
  1810                                  ;3:
  1811                                  ;	jsr	pc,getc / get digit after $
  1812                                  ;	sub	$'0,r0 / strip off zone bits
  1813                                  ;	cmp	r0,$9. / compare with digit 9 
  1814                                  ;	blos	1f / less than or equal 9
  1815                                  ;	mov	$9.,r0 / if larger than 9, force 9
  1816                                  ;1:
  1817                                  ;	mov	shellarg,r1 / get pointer to stack for
  1818                                  ;		            / this call of shell
  1819                                  ;	inc	r0 / digit +1
  1820                                  ;	cmp	r0,(r1) / is it less than # of args in this call
  1821                                  ;	bge	getc / no, ignore it. so this $n is not replaced
  1822                                  ;	asl	r0 / yes, multiply by 2 (to skip words)
  1823                                  ;	add	r1,r0 / form pointer to arg pointer (-2)
  1824                                  ;	mov	2(r0),param / move arg pointer to param
  1825                                  ;	br	getc / go to get substitution arg for $n
  1826                                  ;getbuf:
  1827                                  ;	mov	$inbuf,r0 / move input buffer address
  1828                                  ;	mov	r0,inbufp / to input buffer pointer
  1829                                  ;	mov	r0,einbuf / and initialize pointer to end of
  1830                                  ;		          / character string
  1831                                  ;	dec	r0 / decrement pointer so can utilize normal
  1832                                  ;		   / 100p starting at 1f
  1833                                  ;	mov	r0,0f / initialize address for reading 1st char
  1834                                  ;1:
  1835                                  ;	inc	0f / this routine filles inbuf with line from
  1836                                  ;		   / console - if there is cnc
  1837                                  ;	clr	r0 / set for tty input
  1838                                  ;	sys	read; 0:0; 1 / read next char into inbuf
  1839                                  ;	bcs	xit1 / error exit
  1840                                  ;	tst	r0 / a zero input is end of file
  1841                                  ;	beq	xit1 / exit
  1842                                  ;	inc	einbuf / eventually einbuf points to \n
  1843                                  ;		       / (+1) of this line
  1844                                  ;	cmp	0b,$inbuf+256. / have we exceeded input buffer size
  1845                                  ;	bhis	xit1 / if so, exit assume some sort of binary
  1846                                  ;	cmpb	*0b,$'\n / end of line?
  1847                                  ;	bne	1b / no, go to get next char
  1848                                  ;	rts	pc / yes, return
  1849                                  ;
  1850                                  ;xit1:
  1851                                  ;	sys	exit
  1852                                  ;
  1853                                  ;quest:
  1854                                  ;	<?\n>
  1855                                  ;
  1856                                  ;at:
  1857                                  ;	<@ >
  1858                                  ;
  1859                                  ;qchdir:
  1860                                  ;	<chdir\0>
  1861                                  ;glogin:
  1862                                  ;	<login\0>
  1863                                  ;shell:
  1864                                  ;	</bin/sh\0>
  1865                                  ;glob:
  1866                                  ;	</etc/glob\0>
  1867                                  ;binpb:
  1868                                  ;	</bin/>
  1869                                  ;parbuf: .=.+1000.
  1870                                  ;	.even
  1871                                  ;param:	.=.+2
  1872                                  ;glflag: .=.+2
  1873                                  ;infile: .=.+2 
  1874                                  ;outfile:.=.+2
  1875                                  ;	.=.+2 / room for glob
  1876                                  ;parp:	.=.+200.
  1877                                  ;inbuf:	.=.+256.
  1878                                  ;escap:	.=.+2
  1879                                  ;inbufp: .=.+2
  1880                                  ;einbuf: .=.+2
  1881                                  ;och:	.=.+2
  1882                                  ;shellarg:.=.+2
