.title	HELP	Help module for IAF
	.ident	/V1.02/
	.sbttl	Documentation
;
;	This is the IAF subroutine that implements the
;	HELP command
;
;	Eric F. Richards
;	2-Apr-87
;	Gould OSD VAXcluster VAX/VMS V4.5
;
;
	.sbttl	Macros, constants, and other rot

	.enable	suppression		; clean up the listing file
	.disable traceback, debug	; hands off with the debugger

	.macro	clrsp space, fill=#0	; macro for clearing space
	subl	space, sp		; on stack for a data area.
	movc5	#0, (sp), fill, -	; data area is init'd to
		  space, (sp)		; nulls by this macro
	.endm	clrsp			; that's it!

	bufsiz	= 132			; size of internal character buffer

	.psect	$code, long, exe, pic, shr, nowrt
	.sbttl	HELP code
	.page
;
;	This subroutine looks up the HELP information
;
	.entry	help, ^m<r2, r3, r4, r5>
	clrsp	#bufsiz			; clear buffer for commadn line
	pushl	sp			; build descriptor for it
	pushl	#bufsiz			; ...length for descriptor
	movl	sp, r5			; save a pointer to the descr
	pushal	topic			; build a descriptor for the
	pushl	s^#topic_len		; ...topic label
	movl	sp, r4			; save a pointer to that one, too
	pushal	libname			; build a descriptor for the lib name
	pushl	#libname_len		; ...for the help to reference
	movl	sp, r3			; save a pointer to that desc, too!

	pushl	r5			; get the help topic to look up
	pushl	r5			; ...and write it (truncated) here
	pushl	r4			; ...label is TOPIC
	calls	#3, g^cli$get_value	; get the value
	blbs	r0, 10$			; on success skip the error handler
	clrl	(r5)			; set the descr length to 0

10$:	pushal	w^get_input		; call the help routine -- input here
	pushl	#0			; use default flags, too
	pushl	r3			; help library name
	pushl	r5			; parameter line to give it
	pushl	#0			; use default terminal width
	pushal	w^put_output		; write the output with this
	calls	#6, g^lbr$output_help	; go into help
	ret				; go back to caller

	.sbttl	Data areas for HELP code
	.page
	.psect	$pdata, long, noexe, nowrt, pic, shr
topic:	.ascii	/TOPIC/			; label for HELP topics
	topic_len = . - topic		; length
	.end				; that's it!