ved_grep.p

/* --- Copyright University of Sussex 2005. All rights reserved. ----------
 > File:            C.unix/lib/ved/ved_grep.p
 > Purpose:         Run grep and read output into a VED file
 > Author:          Aaron Sloman, Oct 14 1990 (see revisions)
 > Documentation:	HELP * VED_GREP
 > Related Files:
 */

/*
  <ENTER> grep [<flags>] <search-string> file1, file2 ...
  <ENTER> grep [<flags>] <search-string> <file-pattern>
  <ENTER> grep [<flags>] <file-pattern>
  <ENTER> grep [<flags>]
*/

section;

uses-by_name vedgenshell;

/*USER-MODIFIABLE DEFAULTS*/

global vars
		grep_search_command = 'grep',
		grep_leave_colons;

global vars show_output_on_status;	;;; used by vedgenshell


/* UTILITIES */

define lconstant explode_substring(i1, i2, string);
	;;; Put the characters between i1 and i2 on the stack.
	;;; If i2 is false, put all characters to end of string on stack
	lvars x, i1, i2, string, len = datalength(string);


	check_string(string);
	checkinteger(i1, 1, len);

	if i2 then
		checkinteger(i2, 1, len);
	else
		len -> i2;
	endif;

	fast_for x from i1 to i2 do
		fast_subscrs(x, string)
	endfor;
enddefine;

define lconstant trim_flags(args) -> args;
	;;; If there are any flags (indicated by `-`) put the characters
	;;; of the leading substring on the stack.
	;;; Return a string with remaining args

	lvars args,
		flags = false,
		n = 1,
		nextspace = false;

	;;; Put all 'flag' arguments on stack as characters.
	while subscrs(n, args) == `-` do
		true -> flags;	;;; indicate flag found
		;;; found `-` so search for space after flag
		locchar(`\s`, n, args) -> nextspace;
	quitunless(nextspace);
		;;; Find start of next arg, i.e. after space
		skipchar(`\s`, nextspace, args) -> n;
	quitunless(n);
	endwhile;

	if nextspace then
		;;; found a space after the last flag arg
		;;; dump all characters up to that point on the stack.
		explode_substring(1, nextspace, args);
		`\s`;
		if n then
			allbutfirst(n - 1, args) -> args;
		else
			;;; only following spaces. (Should not be possible)
			nullstring -> args;
		endif
	elseif flags then
		;;; no following space, so it is all flags
		explode(args), `\s`;
		nullstring-> args;
	else
		;;; no flags found, args unchanged
	endif;

enddefine;

define lconstant quotify(arg, index);
	;;; Arg is a string with at least one space, at location index.
	;;; Put the first space-bounded text between quotes (').
	;;; Put all remaining characters on the stack
	lvars arg, index;

		`'`,	;;; opening string quote
		explode_substring(1, index - 1, arg);
		`'`;		;;; closing string quote

		explode_substring(index, false, arg);
enddefine;

define lconstant next_string_in_line() -> string;
	;;; get space/tab delimited string to right of cursor,
	;;; excluding trailing . or ,.
	;;; Uses the mechanism employed by vedexpandchar, in SRC * vdprocess.p
	lvars string;
	pdpart(vedexpandchars(`f`))('\s\t\n();,[]{}|><~&*?`\'"', '.,') -> string;
enddefine;

define global vars procedure ved_grep;
	lvars index, oldfile = vedcurrentfile;

	dlocal show_output_on_status = false, vedargument;

	;;; Save vedsearch state
	dlocal ved_search_state;

	unless isboolean(grep_leave_colons) then
		false -> grep_leave_colons
	endunless;

	;;; now create second argument for vedgenshell

	consstring(#|
		explode(grep_search_command), `\s`,
		if vedargument = nullstring then
			;;; use the whole of the current VED line
			explode(vedthisline())
		else
			;;; get any grep" flags" from vedargument
			trim_flags(vedargument) -> vedargument;

            if vedargument = nullstring then
				;;; use the whole of the current VED line
				explode(vedthisline())
			elseif (strmember(`\s`, vedargument) ->> index) then
				;;; There is a search string. Put it between "'" quotes
				;;; to be safe, unless already there.
				if fast_subscrs(1,vedargument) == `'` then
					explode(vedargument)
				else
					;;; insert quotes around initial arg
					quotify(vedargument, index)
				endif
			else
				;;; DODGY !!!
				;;; no searchstring argument. So get it from current line.
				;;; remainder of vedargument is the file spec.
				explode(next_string_in_line()), `\s`, explode(vedargument)
			endif

		endif
		|#) -> vedargument;

	valof("vedgenshell") (systranslate('SHELL') or '/bin/sh', vedargument);

	;;; Now prepare file so that filenames are delimited by spaces

	unless oldfile == vedcurrentfile or grep_leave_colons then
		;;; get rid of first colon in each line
		dlocal vedstatic = true;
		lblock lvars line, loc;
			for line from 1 to vvedbuffersize do
				if locchar(`:`, 1, subscrv(line,vedbuffer)) ->> loc then
					vedjumpto(line, loc);
					veddotdelete();
				endif
			endfor
		endlblock;

		vedjumpto(1,1)

	endunless;
enddefine;

endsection;

/* --- Revision History ---------------------------------------------------
--- Aaron Sloman, Jan 12 2005
		Imported some improvements from Bham version, including
		wrapping search arg in quotes.
--- Aaron Sloman, Jan 30 1999
	Got rid of test for ngrep
--- Aaron Sloman, 29 Dec 1997
	Changed so as not to insert quotes if already there.
--- John Williams, Jan  7 1997
		Now uses $SHELL if set (/bin/sh otherwise), as per BR joew.12.
--- Aaron Sloman, Oct 15 1995
		Fixed bug to do with indexing into strings.
--- Aaron Sloman, Oct 14 1995
		Changed default command back to egrep, since it offers more
		flexibility
		Renamed analyse_argument as trim_flags, and introduced
		explode_substring.
--- Aaron Sloman, Sep 3 1995
		Changed to use 'grep' if 'ngrep' is not available, since egrep
		can be slower
--- John Gibson, Aug  2 1995
		Made initialisation of grep_search_command be done at runtime
--- Jonathan Meyer, Sep 29 1993
		Changed vvedsr*ch vars to ved_search_state
--- John Williams, Aug  4 1992
		Made -ved_grep- global (cf BR isl-fr.4461)
--- Aaron Sloman, Aug 18 1992
	changed to use ngrep for local birmingham version
--- Aaron Sloman, Oct 21 1990
	Restricted test for 'ggrep' to sussex
--- Aaron Sloman, Oct 16 1990
	Completely replaced and generalised previous version. Provided
	HELP file
 */