gno/bin/gsh/main.asm

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**************************************************************************
*
* The GNO Shell Project
*
* Developed by:
* Jawaid Bazyar
* Tim Meekins
*
* $Id: main.asm,v 1.8 1999/01/14 17:44:25 tribby Exp $
*
**************************************************************************
*
* MAIN.ASM
* By Tim Meekins
* Modified by Dave Tribby for GNO 2.0.6
*
* Startup portion of shell
*
* Note: text set up for tabs at col 16, 22, 41, 49, 57, 65
* | | | | | |
* ^ ^ ^ ^ ^ ^
**************************************************************************
mcopy /obj/gno/bin/gsh/main.mac
setcom 60
**************************************************************************
; Segment for direct-page and stack
stack data STACK ; ends up in main.root
kind $12
; Define direct-page/stack and fill it with question marks it can be
; examined for how much is used.
dc 128c'??' ; 256 bytes
dc 128c'??' ; 512 bytes total
dc 128c'????' ; 1024 bytes total
dc 128c'????????' ; 2048 bytes total
end
**************************************************************************
init START
; Call the code to emulate C program startup:
; store Accumulator in ~USER_ID, X- and Y- registers as ~COMMANDLINE
; start up memory manager (~MM_INIT)
; parse commandline (via ~GNO_PARSEARG) and push argc and arvg on stack
jml ~GNO_COMMAND
; Control continues with the entry point "MAIN". When MAIN returns to
; ~GNO_COMMAND via rtl, it frees argv and argc before doing its own rtl.
END
MAIN START
using global
p equ 0
arg equ p+4
space equ arg+4
subroutine (2:argc,4:argv),space
kernStatus @a
bcc ok
ErrWriteCString #str
jmp done
ok stz FastFlag
stz CmdFlag
stz ExecFlag
; Parse gsh's command-line arguments.
argloop dec argc Decrement argument count.
jeq go_start If none left, ready to start working.
clc
lda argv Point to next
adc #4 argument pointer.
sta argv
ldy #2
lda [argv] Set arg to point to
sta arg the argument text.
lda [argv],y
sta arg+2
lda [arg] Get first character
and #$FF of argument.
cmp #'-' If it's a "-",
beq intoption handle as an option.
; Parse remaining args as a command to run (in ExecCmd)
inc ExecFlag
inc FastFlag
ph4 #1024
~NEW
sta ExecCmd
sta p
stx ExecCmd+2
stx p+2
cmd3 ldy #0
cmd0 lda [arg],y
and #$ff
beq cmd1
sta [p],y
iny
bra cmd0
cmd1 lda #' '
sta [p],y
sec ;inc a
tya
adc p
sta p
dec argc
beq cmd2
clc
lda argv
adc #4
sta argv
ldy #2
lda [argv]
sta arg
lda [argv],y
sta arg+2
bra cmd3
cmd2 lda #0
sta [p]
go_start bra start
; Parse an argument as an option (first character is "-")
intoption ldy #1
optloop lda [arg],y
and #$FF
beq nextarg
cmp #'f'
beq optf
cmp #'c'
beq parsec
; Option is not recognized.
showusage ErrWriteCString #usage
bra done
; Option = "-f": Skip history, gshrc
optf inc FastFlag
nextopt iny
bra optloop
nextarg cpy #1
beq showusage
jmp argloop
; Option = "-c": execute shell commands found in file named by next argument
parsec clc
lda argv
adc #4
sta argv
dec argc
beq showusage
inc CmdFlag
inc FastFlag
mv4 argv,CmdArgV
mv2 argc,CmdArgC
;
; When preliminary setup is complete, control transfers to here!
;
start case on
jsl shell
case off
done return
str dc h'0d0a0a'
dc c'Before gsh may be run, the GNO/ME system, or kernel, must be running.'
dc h'0d0a0a00'
usage dc c'Usage: gsh [-cf] [argument...]',h'0d0a00'
END