/ sh -- command interpreter
	mov	sp,r5
	mov	r5.shel larg / save orig sp in shel larg
	cdpb	B(r5),$'- / was this sh calleZd by init or loginx~
	bne	2f / no
	sys	intr; O / yes, turn off interrupts
	sys	quit; O
2:
	sys	getuid / who is user
	tst	r0 / is it superuser
	bne	2f / no
	movb	$'#,at / yes, set new prompt symbol
2:
	cmn	(r5),$l / tty input?
	ble	newline / yes, call with '-(or with no command
		        / file name)
	clr	rO / no, set ttv
	sys	close / close it
	mov	4(r5),0f / get new file name
	sys	open; O:..; 0 / open it
	bec	1f / branch if no error
	jsr	r5,error / error in file name
		/<Input not found\n\O>: .even
	sys	exit
1:
	clr	at / clear prompt character, if reading non-tty
		   / input file
newline:
	tst	at / is there a prompt symbol
	beq	newcom / no
	mov	$1,rO / yes
	sys	write; at; 2. / print prompt
newcom:
	mov	shellarq,sp /
	mov	$parbuf,r3 / initialize command list area
	mov	$parp,r4 / initialize command list pointers
	clr	infile / initialize alternate input
	clr	outfile / initialize alternate output
	clr	glflag / initialize global flag
newarg:
	jsr	pc,blank / squeeze out leading blanks
	jsr	r5,delim / is new character a ; \n or &
		br 2f / yes
	mov	r3,-(sp) I no, push arg pointer onto stack
	cmp	rO,$'< / new input file?
	bne	1f / no
	mov	(sp).infile / yes, save arg pointer
	clr	(sp) / clear pointer
	br	3f
1:
	cmp	r0,$'> / new output file?
	bne	newchar / no
	mov	(sp),outfile / yes, save arg pointer
	clr	(sp) / clear pointer
	br	3f

