/ sh -- command interpreter
mov r5,shellarg / save orig sp in shellarg
cmpb *2(r5),$'- / was this sh calleZd by init or loginx~
sys intr; 0 / yes, turn off interrupts
movb $'#,at / yes, set new prompt symbol
ble newline / yes, call with '-(or with no command
mov 4(r5),0f / get new file name
sys open; 0:..; 0 / open it
bec 1f / branch if no error
jsr r5,error / error in file name
<Input not found\n\0>; .even
clr at / clear prompt character, if reading non-tty
tst at / is there a prompt symbol
sys write; at; 2. / print prompt
mov $parbuf,r3 / initialize command list area
mov $parp,r4 / initialize command list pointers
clr infile / initialize alternate input
clr outfile / initialize alternate output
clr glflag / initialize global flag
jsr pc,blank / squeeze out leading blanks
jsr r5,delim / is new character a ; \n or &
mov r3,-(sp) / no, push arg pointer onto stack
cmp r0,$'< / new input file?
mov (sp),infile / yes, save arg pointer
cmp r0,$'> / new output file?
mov (sp),outfile / yes, save arg pointer
cmp $' ,r0 / is character a blank
beq 1f / branch if it is (blank as arg separator)
cmp $'\n+200,r0 / treat \n preceded by \
jsr pc,putc / put this character in parbuf list
jsr pc,getc / get next character
jsr r5,delim / is char a ; \n or &,
br newchar / no, start new character tests
clrb (r3)+ / end name with \0 when read blank, or
mov (sp)+,(r4)+ / move arg ptr to parp location
bne 1f / if (sp)=0, in file or out file points to arg
tst -(r4) / so ignore dummy (0), in pointer list
jsr r5,delim / is char a ; \n or &.
br newarg / no, start newarg processing
clr (r4) / \n, &, or ; takes to here (end of arg list)
mov r0,-(sp) / save delimter in stack
jsr pc,docom / go to exec command in parbuf
cmpb (sp),$'& / get a new command without wait?
tst r1 / was chdir just executed or line ended with
sys wait / no, wait for new process to terminate
bcs 2f / no, children not previously waited for
cmp r0,r1 / is this my child
cmp (sp),$'\n / was delimiter a new line
br newcom / no, pick up next command
sub $parp,r4 / out arg count in r4
clr r1 / no, line ended with ampersand
rts pc / return from call
jsr r5,chcom; qchdir / is command chdir?
br 2f / command not chdir
cmp r4,$4 / prepare to exec chdir, 4=arg count x 2
jsr r5,error / go to print error
mov parp+2,0f / more directory name to sys coll
sys chdir; 0:0 / exec chdir
jsr r5,error / go to print error
<Bad directory\n\0>; .even / this diagnostic
clr r1 / set r1 to zero to dkip wait
jsr r5,chcom; glogin / is command login?
br 2f / not loqin, go to fork
sys exec; parbuf; parp / exec login
sys exec; binpb; parp / or /bin/login
sys fork / generate sh child process for command
br newproc / exec command with new process
bec 1f / no error exit, old orocess
jsr r5,error / go to print error
<Try again\n\0>; .even / this diaonostic
jmp newline / and return for next try
mov r0,r1 / save id of child sh
rts pc / return to "jsr pc, docom" call in parent sh
movb (r5)+,och / pick up diagnostic character
beq 1f / 0 is end of line
mov $1,r0 / set for tty output
sys write; och; 1 / print it
br error / continue to get characters
inc r5 / inc r5 to point to return
sys seek; 0; 2 / exit from runcom. skip to end of
chcom: / has no effect if tty input
mov (r5)+,r1 / glogin gchdir r1, bump r5
mov $parbuf,r2 / command address r2 'login'
movb (r1)+,r0 / is this command 'chdir'
cmpb (r2)+,r0 / compare command name byte with 'login'
tst (r5)+ / yes, bump r5 again to execute login
rts r5 / no, return to exec command
cmp r0,$'' / single quote?
cmp r0,$'" / double quote
bic $!177,r0 / no, remove 200, if present
movb r0,(r3)+ / store character in parbuf
mov r0,-(sp) / push quote mark onto stack
jsr pc,getc / get a quoted character
cmp r0,$'\n / is it end or line
jsr r5,error / yes, indicate missing quote mark
<"' imbalance\n\0>; .even
jmp newline / ask for new line
cmp r0,(sp) / is this closing quote mark
bic $!177,r0 / no, strip off 200 if present
movb r0,(r3)+ / store quoted character in parbuf
tst (sp)+ / pop quote mark off stack
mov infile,0f / move pointer to new file name
beq 1f / branch if no alternate read file given
beq 3f / branch if no file name miven
clr r0 / set tty input file name
sys open; 0:..; 0 / open new input file for reading
bcc 1f / branch if input file ok
jsr r5,error / file not ok, print error
<Input file\n\0>; .even / this diagnostic
sys exit / terminate this process and make parent sh
mov outfile,r2 / more pointer to new file name
beq 1f / branch if no alternate write file
cmpb (r2),$'> / is > at beqinninrg of file name?
bne 4f / branch if it isn't
inc r2 / yes, increment pointer
sys open; 0:..; 1 / open file for writing
sys creat; 0:..; 17 / create new file with this name
bec 3f / branch if no error
sys close / close the new write file
mov r2,0f / move new name to open
mov $1,r0 / set ttv file name
sys open; 0:..; 1 / open new output file, it now has
sys seek; 0; 2 / set pointer to current end of file
tst glflag / was *, ? or [ encountered?
sys exec; parbuf; parp / no, execute this commend
sys exec; binpb; parp / or /bin/this command
sys stat; binpb; inbuf / if can't execute does it
bes 2f / branch if it doesn't
mov $shell,parp-2 / does exist, not executable
mov $binpb,parp / so it must be
sys exec; shell; parp-2 / a command file, get it with
/ sh /bin/x (if x name of file)
jsr r5,error / a return for exec is the diagnostic
mov $glob,parp-2 / prepare to process *,?
sys exec; glob; parp-2 / execute modified command
cmp r0,$'\n / is character a newline
cmp r0,$'[ / is it beginning of character string
inc glflag / ? or * or [ set flag
tst (r5)+ / bump to process all except \n,;,&
jsr pc,getc / get next character
cmp $' ,r0 / leading blanks
beq blank / yes, 'squeeze out'
cmp r0,$200+'\n / new-line preceded by \ is translated
tst param / are we substituting for $n
mov inbufp,r1 / no, move normal input pointer to r1
cmp r1,einbuf / end of input line?
jsr pc,getbuf / yes, put next console line in buffer
movb (r1)+,r0 / move byte from input buffer to r0
mov r1,inbufp / increment routine
bis escap,r0 / if last character was \ this adds
/ 200 to current character
clr escap / clear, so escap normally zero
cmp r0,$'\\ / note that \\ is equal \ in as
mov $200,escap / mark presence of \ in command line
br getc / get next character
movb *param,r0 / pick up substitution character put in
beq 1f / if end of substitution arg, branch
inc param / if not end, set for next character
rts pc / return as though character in ro is normal
clr param / unset substitution pointer
br getc / get next char in normal input
jsr pc,getc / get digit after $
sub $'0,r0 / strip off zone bits
cmp r0,$9. / compare with digit 9
blos 1f / less than or equal 9
mov $9.,r0 / if larger than 9, force 9
mov shellarg,r1 / get pointer to stack for
cmp r0,(r1) / is it less than # of args in this call
bge getc / no, ignore it. so this $n is not replaced
asl r0 / yes, multiply by 2 (to skip words)
add r1,r0 / form pointer to arg pointer (-2)
mov 2(r0),param / move arg pointer to param
br getc / go to get substitution arg for $n
mov $inbuf,r0 / move input buffer address
mov r0,inbufp / to input buffer pointer
mov r0,einbuf / and initialize pointer to end of
dec r0 / decrement pointer so can utilize normal
mov r0,0f / initialize address for reading 1st char
inc 0f / this routine filles inbuf with line from
/ console - if there is cnc
clr r0 / set for tty input
sys read; 0:0; 1 / read next char into inbuf
tst r0 / a zero input is end of file
inc einbuf / eventually einbuf points to \n
cmp 0b,$inbuf+256. / have we exceeded input buffer size
bhis xit1 / if so, exit assume some sort of binary
cmpb *0b,$'\n / end of line?
bne 1b / no, go to get next char
projects / unix-history / blob