Introduce usagef() that takes a printf-style format

diff --git a/builtin-grep.c b/builtin-grep.c
index 761799d7d0afd62ecba99d703a8595664faa4723..01be9bf7ff74731969384cc91dad2e20d08d81bc 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -631,7 +631,7 @@ static int file_callback(const struct option *opt, const char *arg, int unset)
        struct grep_opt *grep_opt = opt->value;
        FILE *patterns;
        int lno = 0;
-       struct strbuf sb;
+       struct strbuf sb = STRBUF_INIT;
 
        patterns = fopen(arg, "r");
        if (!patterns)
@@ -788,6 +788,13 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                OPT_END()
        };
 
+       /*
+        * 'git grep -h', unlike 'git grep -h <pattern>', is a request
+        * to show usage information and exit.
+        */
+       if (argc == 2 && !strcmp(argv[1], "-h"))
+               usage_with_options(grep_usage, options);
+
        memset(&opt, 0, sizeof(opt));
        opt.prefix = prefix;
        opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;