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diff --git a/builtin-grep.c b/builtin-grep.c
index e13cb31f2b9dd63d335437fb5b1c9b0b06fbf188..0d6cc7361f6e1a70e4d3d9e24913d60e8ceb9e58 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
else die("maximum number of args exceeded"); \
} while (0)
+/*
+ * If you send a singleton filename to grep, it does not give
+ * the name of the file. GNU grep has "-H" but we would want
+ * that behaviour in a portable way.
+ *
+ * So we keep two pathnames in argv buffer unsent to grep in
+ * the main loop if we need to do more than one grep.
+ */
+static int flush_grep(struct grep_opt *opt,
+ int argc, int arg0, const char **argv, int *kept)
+{
+ int status;
+ int count = argc - arg0;
+ const char *kept_0 = NULL;
+
+ if (count <= 2) {
+ /*
+ * Because we keep at least 2 paths in the call from
+ * the main loop (i.e. kept != NULL), and MAXARGS is
+ * far greater than 2, this usually is a call to
+ * conclude the grep. However, the user could attempt
+ * to overflow the argv buffer by giving too many
+ * options to leave very small number of real
+ * arguments even for the call in the main loop.
+ */
+ if (kept)
+ die("insanely many options to grep");
+
+ /*
+ * If we have two or more paths, we do not have to do
+ * anything special, but we need to push /dev/null to
+ * get "-H" behaviour of GNU grep portably but when we
+ * are not doing "-l" nor "-L" nor "-c".
+ */
+ if (count == 1 &&
+ !opt->name_only &&
+ !opt->unmatch_name_only &&
+ !opt->count) {
+ argv[argc++] = "/dev/null";
+ argv[argc] = NULL;
+ }
+ }
+
+ else if (kept) {
+ /*
+ * Called because we found many paths and haven't finished
+ * iterating over the cache yet. We keep two paths
+ * for the concluding call. argv[argc-2] and argv[argc-1]
+ * has the last two paths, so save the first one away,
+ * replace it with NULL while sending the list to grep,
+ * and recover them after we are done.
+ */
+ *kept = 2;
+ kept_0 = argv[argc-2];
+ argv[argc-2] = NULL;
+ argc -= 2;
+ }
+
+ status = exec_grep(argc, argv);
+
+ if (kept_0) {
+ /*
+ * Then recover them. Now the last arg is beyond the
+ * terminating NULL which is at argc, and the second
+ * from the last is what we saved away in kept_0
+ */
+ argv[arg0++] = kept_0;
+ argv[arg0] = argv[argc+1];
+ }
+ return status;
+}
+
static int external_grep(struct grep_opt *opt, const char **paths, int cached)
{
int i, nr, argc, hit, len, status;
if (opt->pre_context) {
push_arg("-B");
len += snprintf(argptr, sizeof(randarg)-len,
- "%u", opt->pre_context);
+ "%u", opt->pre_context) + 1;
if (sizeof(randarg) <= len)
die("maximum length of args exceeded");
push_arg(argptr);
if (opt->post_context) {
push_arg("-A");
len += snprintf(argptr, sizeof(randarg)-len,
- "%u", opt->post_context);
+ "%u", opt->post_context) + 1;
if (sizeof(randarg) <= len)
die("maximum length of args exceeded");
push_arg(argptr);
else {
push_arg("-C");
len += snprintf(argptr, sizeof(randarg)-len,
- "%u", opt->post_context);
+ "%u", opt->post_context) + 1;
if (sizeof(randarg) <= len)
die("maximum length of args exceeded");
push_arg(argptr);
@@ -253,22 +325,12 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
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;
+ int kept;
if (!S_ISREG(ntohl(ce->ce_mode)))
continue;
if (!pathspec_matches(paths, ce->name))
@@ -281,12 +343,12 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
memcpy(name + 2, ce->name, len + 1);
}
argv[argc++] = name;
- if (argc < MAXARGS && !ce_stage(ce))
- continue;
- status = exec_grep(argc, argv);
- if (0 < status)
- hit = 1;
- argc = nr;
+ if (MAXARGS <= argc) {
+ status = flush_grep(opt, argc, nr, argv, &kept);
+ if (0 < status)
+ hit = 1;
+ argc = nr + kept;
+ }
if (ce_stage(ce)) {
do {
i++;
}
}
if (argc > nr) {
- status = exec_grep(argc, argv);
+ status = flush_grep(opt, argc, nr, argv, NULL);
if (0 < status)
hit = 1;
}
die("'%s': %s", argv[1], strerror(errno));
while (fgets(buf, sizeof(buf), patterns)) {
int len = strlen(buf);
- if (buf[len-1] == '\n')
+ if (len && buf[len-1] == '\n')
buf[len-1] = 0;
/* ignore empty line like grep does */
if (!buf[0])