Thompson MSH(mini-shell) Post: 302952164

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Top Forums Shell Programming and Scripting Thompson MSH(mini-shell) Post 302952164 by GLbS on Friday 14th of August 2015 10:48:54 AM

08-14-2015

Registered User

Thompson MSH(mini-shell)

Hi Guys!

Recently, I disassemble the MSH. And reconstructed. I thought maybe somebody wants to see looked like a second shell. In practice, the most ancient shell. It is written in assembler (AT&T). Owner Ken Thompson, Dennis Ritchie.

Code:

	mov	$parbuf,r1
	mov	$parp,r2
	clr	r3
	jsr	pc,blank
	cmp	r0,$'\n  /
	bne	1f
	sys	exit
1:
	mov	r1,(r2)+
2:
	movb	r0,(r1)+
	jsr	pc,getchar
	cmp	r0,$' / space
	beq	3f
	cmp	r0,$'\n  /
	beq	1f
	br	2b
3:
	clrb	(r1)+
	jsr	pc,blank
	cmp	r0,$'\n  /
	beq	1f
	br	1b
1:
	clr	(r2)+
	tst	r3
	bne	1f
	sys	exec; parbuf; parp /
	sys	exec; binpb; parp /
	br	2f
1:
	mov	$glob,parp
	sys	exec; glob; parp /
2:
	mov	$1,r0	
	sys	write; quest; 2. 
	sys	exit
quest:
	<? >
blank:
	jsr	pc,getchar
	cmp	r0,$' / space
	beq	blank
	rts	pc
getchar:
	clr	r0
	sys	read; chr; 1 / read char
	bcs	xit1
	tst	r0
	beq	xit1
	movb	chr,r0
	cmp	r0,$'? /
	beq	1f
	cmp	r0,$'* /
	beq	1f
	cmp	r0,$'[ /
	bne	2f
1:
	inc	r3
2:
	rts	pc
xit1:
	sys	exit

chr:	.=.+1
glob:
	</etc/glob\0> / globbing
binpb:
	</bin/>
parbuf:	.=.+1000.
parp:		.=.+200.     / real size unknown

Full description in Unix Programmer's Manual, First Edition.
Or here(see below): login(7) - Unix First Edition Manual Page

Last edited by GLbS; 08-14-2015 at 01:08 PM..

GLbS

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ZDIFF(1)						      General Commands Manual							  ZDIFF(1)

NAME

       zcmp, zdiff - compare compressed files

SYNOPSIS

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       zdiff [ diff_options ] file1 [ file2 ]

DESCRIPTION

       Zcmp  and  zdiff are used to invoke the cmp or the diff program on files compressed via gzip.  All options specified are passed directly to
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SEE ALSO

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BUGS

       Messages from the cmp or diff programs may refer to file names such as "-" instead of to the file names specified.

																	  ZDIFF(1)