X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=builtin-grep.c;h=53de8a883607157c88d02a30f0320aa9e5c0581a;hb=47df096f254ccac5a81da615b3fd25f3cf466bbf;hp=fead35662944070f8502ed0484fe6b6085d7ac86;hpb=07ea91d84f3c7bb075d4716ee40096e3b12a4c86;p=git.git

diff --git a/builtin-grep.c b/builtin-grep.c
index fead3566..53de8a88 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -12,6 +12,7 @@
 #include "builtin.h"
 #include <regex.h>
 #include <fnmatch.h>
+#include <sys/wait.h>
 
 /*
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
@@ -409,12 +410,156 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 	return i;
 }
 
+static int exec_grep(int argc, const char **argv)
+{
+	pid_t pid;
+	int status;
+
+	argv[argc] = NULL;
+	pid = fork();
+	if (pid < 0)
+		return pid;
+	if (!pid) {
+		execvp("grep", (char **) argv);
+		exit(255);
+	}
+	while (waitpid(pid, &status, 0) < 0) {
+		if (errno == EINTR)
+			continue;
+		return -1;
+	}
+	if (WIFEXITED(status)) {
+		if (!WEXITSTATUS(status))
+			return 1;
+		return 0;
+	}
+	return -1;
+}
+
+#define MAXARGS 1000
+#define ARGBUF 4096
+#define push_arg(a) do { \
+	if (nr < MAXARGS) argv[nr++] = (a); \
+	else die("maximum number of args exceeded"); \
+	} while (0)
+
+static int external_grep(struct grep_opt *opt, const char **paths, int cached)
+{
+	int i, nr, argc, hit, len;
+	const char *argv[MAXARGS+1];
+	char randarg[ARGBUF];
+	char *argptr = randarg;
+	struct grep_pat *p;
+
+	len = nr = 0;
+	push_arg("grep");
+	if (opt->fixed)
+		push_arg("-F");
+	if (opt->linenum)
+		push_arg("-n");
+	if (opt->regflags & REG_EXTENDED)
+		push_arg("-E");
+	if (opt->word_regexp)
+		push_arg("-w");
+	if (opt->name_only)
+		push_arg("-l");
+	if (opt->unmatch_name_only)
+		push_arg("-L");
+	if (opt->count)
+		push_arg("-c");
+	if (opt->post_context || opt->pre_context) {
+		if (opt->post_context != opt->pre_context) {
+			if (opt->pre_context) {
+				push_arg("-B");
+				len += snprintf(argptr, sizeof(randarg)-len,
+						"%u", opt->pre_context);
+				if (sizeof(randarg) <= len)
+					die("maximum length of args exceeded");
+				push_arg(argptr);
+				argptr += len;
+			}
+			if (opt->post_context) {
+				push_arg("-A");
+				len += snprintf(argptr, sizeof(randarg)-len,
+						"%u", opt->post_context);
+				if (sizeof(randarg) <= len)
+					die("maximum length of args exceeded");
+				push_arg(argptr);
+				argptr += len;
+			}
+		}
+		else {
+			push_arg("-C");
+			len += snprintf(argptr, sizeof(randarg)-len,
+					"%u", opt->post_context);
+			if (sizeof(randarg) <= len)
+				die("maximum length of args exceeded");
+			push_arg(argptr);
+			argptr += len;
+		}
+	}
+	for (p = opt->pattern_list; p; p = p->next) {
+		push_arg("-e");
+		push_arg(p->pattern);
+	}
+
+	/*
+	 * To make sure we get the header printed out when we want it,
+	 * add /dev/null to the paths to grep.  This is unnecessary
+	 * (and wrong) with "-l" or "-L", which always print out the
+	 * name anyway.
+	 *
+	 * GNU grep has "-H", but this is portable.
+	 */
+	if (!opt->name_only && !opt->unmatch_name_only)
+		push_arg("/dev/null");
+
+	hit = 0;
+	argc = nr;
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		char *name;
+		if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))
+			continue;
+		if (!pathspec_matches(paths, ce->name))
+			continue;
+		name = ce->name;
+		if (name[0] == '-') {
+			int len = ce_namelen(ce);
+			name = xmalloc(len + 3);
+			memcpy(name, "./", 2);
+			memcpy(name + 2, ce->name, len + 1);
+		}
+		argv[argc++] = name;
+		if (argc < MAXARGS)
+			continue;
+		hit += exec_grep(argc, argv);
+		argc = nr;
+	}
+	if (argc > nr)
+		hit += exec_grep(argc, argv);
+	return 0;
+}
+
 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 {
 	int hit = 0;
 	int nr;
 	read_cache();
 
+#ifdef __unix__
+	/*
+	 * Use the external "grep" command for the case where
+	 * we grep through the checked-out files. It tends to
+	 * be a lot more optimized
+	 */
+	if (!cached) {
+		hit = external_grep(opt, paths, cached);
+		if (hit >= 0)
+			return hit;
+	}
+#endif
+
 	for (nr = 0; nr < active_nr; nr++) {
 		struct cache_entry *ce = active_cache[nr];
 		if (ce_stage(ce) || !S_ISREG(ntohl(ce->ce_mode)))