Merge branch 'jc/grep' into next

* jc/grep:
  builtin-grep: documentation
  Teach -f <file> option to builtin-grep.

Documentation/git-grep.txt

@@ -8,43 +8,82 @@ git-grep - Print lines matching a pattern
 
 SYNOPSIS
 --------
-'git-grep' [<option>...] [-e] <pattern> [--] [<path>...]
+[verse]
+'git-grep' [--cached]
+	   [-a | --text] [-I] [-i | --ignore-case] [-w | --word-regexp]
+	   [-v | --invert-match]
+	   [-E | --extended-regexp]  [-G | --basic-regexp]
+	   [-n] [-l | --files-with-matches] [-L | --files-without-match]
+	   [-c | --count]
+	   [-A <post-context>] [-B <pre-context>] [-C <context>]
+	   [-f <file>] [-e <pattern>]
+	   [<tree>...]
+	   [--] [<path>...]
 
 DESCRIPTION
 -----------
-Searches list of files `git-ls-files` produces for lines
+Look for specified patterns in the working tree files, blobs
-containing a match to the given pattern.
+registered in the index file, or given tree objects.
 
 
 OPTIONS
 -------
+--cached::
+	Instead of searching in the working tree files, check
+	the blobs registerd in the index file.
+
+-a | --text::
+	Process binary files as if they were text.
+
+-i | --ignore-case::
+	Ignore case differences between the patterns and the
+	files.
+
+-w | --word-regexp::
+	Match the pattern only at word boundary (either begin at the
+	beginning of a line, or preceded by a non-word character; end at
+	the end of a line or followed by a non-word character).
+
+-v | --invert-match::
+	Select non-matching lines.
+
+-E | --extended-regexp | -G | --basic-regexp::
+	Use POSIX extended/basic regexp for patterns.  Default
+	is to use basic regexp.
+
+-n::
+	Prefix the line number to matching lines.
+
+-l | --files-with-matches | -L | --files-without-match::
+	Instead of showing every matched line, show only the
+	names of files that contain (or do not contain) matches.
+
+-c | --count::
+	Instead of showing every matched line, show the number of
+	lines that match.
+
+-[ABC] <context>::
+	Show `context` trailing (`A` -- after), or leading (`B`
+	-- before), or both (`C` -- context) lines, and place a
+	line containing `--` between continguous groups of
+	matches.
+
+-f <file>::
+	Read patterns from <file>, one per line.
+
+`<tree>...`::
+	Search blobs in the trees for specified patterns.
+
 `--`::
 	Signals the end of options; the rest of the parameters
 	are <path> limiters.
 
-<option>...::
-	Either an option to pass to `grep` or `git-ls-files`.
-+
-The following are the specific `git-ls-files` options
-that may be given: `-o`, `--cached`, `--deleted`, `--others`,
-`--killed`, `--ignored`, `--modified`, `--exclude=\*`,
-`--exclude-from=\*`, and `--exclude-per-directory=\*`.
-+
-All other options will be passed to `grep`.
-
-<pattern>::
-	The pattern to look for.  The first non option is taken
-	as the pattern; if your pattern begins with a dash, use
-	`-e <pattern>`.
-
-<path>...::
-	Optional paths to limit the set of files to be searched;
-	passed to `git-ls-files`.
-
 
 Author
 ------
-Written by Linus Torvalds <torvalds@osdl.org>
+Originally written by Linus Torvalds <torvalds@osdl.org>, later
+revamped by Junio C Hamano.
+
 
 Documentation
 --------------

builtin-grep.c

@@ -82,6 +82,8 @@ static int pathspec_matches(const char **paths, const char *name)
 
 struct grep_pat {
 	struct grep_pat *next;
+	const char *origin;
+	int no;
 	const char *pattern;
 	regex_t regexp;
 };
@@ -105,10 +107,13 @@ struct grep_opt {
 	unsigned post_context;
 };
 
-static void add_pattern(struct grep_opt *opt, const char *pat)
+static void add_pattern(struct grep_opt *opt, const char *pat,
+			const char *origin, int no)
 {
 	struct grep_pat *p = xcalloc(1, sizeof(*p));
 	p->pattern = pat;
+	p->origin = origin;
+	p->no = no;
 	*opt->pattern_tail = p;
 	opt->pattern_tail = &p->next;
 	p->next = NULL;
@@ -121,9 +126,17 @@ static void compile_patterns(struct grep_opt *opt)
 		int err = regcomp(&p->regexp, p->pattern, opt->regflags);
 		if (err) {
 			char errbuf[1024];
+			char where[1024];
+			if (p->no)
+				sprintf(where, "In '%s' at %d, ",
+					p->origin, p->no);
+			else if (p->origin)
+				sprintf(where, "%s, ", p->origin);
+			else
+				where[0] = 0;
 			regerror(err, &p->regexp, errbuf, 1024);
 			regfree(&p->regexp);
-			die("'%s': %s", p->pattern, errbuf);
+			die("%s'%s': %s", where, p->pattern, errbuf);
 		}
 	}
 }
@@ -482,7 +495,6 @@ int cmd_grep(int argc, const char **argv, char **envp)
 {
 	int hit = 0;
 	int no_more_flags = 0;
-	int seen_noncommit = 0;
 	int cached = 0;
 	struct grep_opt opt;
 	struct object_list *list, **tail, *object_list = NULL;
@@ -598,9 +610,32 @@ int cmd_grep(int argc, const char **argv, char **envp)
 			}
 			continue;
 		}
+		if (!strcmp("-f", arg)) {
+			FILE *patterns;
+			int lno = 0;
+			char buf[1024];
+			if (argc <= 1)
+				usage(builtin_grep_usage);
+			patterns = fopen(argv[1], "r");
+			if (!patterns)
+				die("'%s': %s", strerror(errno));
+			while (fgets(buf, sizeof(buf), patterns)) {
+				int len = strlen(buf);
+				if (buf[len-1] == '\n')
+					buf[len-1] = 0;
+				/* ignore empty line like grep does */
+				if (!buf[0])
+					continue;
+				add_pattern(&opt, strdup(buf), argv[1], ++lno);
+			}
+			fclose(patterns);
+			argv++;
+			argc--;
+			continue;
+		}
 		if (!strcmp("-e", arg)) {
 			if (1 < argc) {
-				add_pattern(&opt, argv[1]);
+				add_pattern(&opt, argv[1], "-e option", 0);
 				argv++;
 				argc--;
 				continue;
@@ -615,7 +650,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
 		if (!no_more_flags && *arg == '-')
 			usage(builtin_grep_usage);
 		if (!opt.pattern_list) {
-			add_pattern(&opt, arg);
+			add_pattern(&opt, arg, "command line", 0);
 			break;
 		}
 		else {
@@ -656,21 +691,9 @@ int cmd_grep(int argc, const char **argv, char **envp)
 
 	if (!object_list)
 		return !grep_cache(&opt, paths, cached);
-	/*
+
-	 * Do not walk "grep -e foo master next pu -- Documentation/"
-	 * but do walk "grep -e foo master..next -- Documentation/".
-	 * Ranged request mixed with a blob or tree object, like
-	 * "grep -e foo v1.0.0:Documentation/ master..next"
-	 * so detect that and complain.
-	 */
-	for (list = object_list; list; list = list->next) {
-		struct object *real_obj;
-		real_obj = deref_tag(list->item, NULL, 0);
-		if (strcmp(real_obj->type, commit_type))
-			seen_noncommit = 1;
-	}
 	if (cached)
-		die("both --cached and revisions given.");
+		die("both --cached and trees are given.");
 
 	for (list = object_list; list; list = list->next) {
 		struct object *real_obj;