Avoid unnecessary strlen() calls

diff --git a/builtin-grep.c b/builtin-grep.c
index 694da5ba09d302c1e44f863070776bc3ac7f32e2..4510d353247355a28979fbf63b15523c2e705591 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -431,6 +431,19 @@ static const char emsg_missing_context_len[] =
 static const char emsg_missing_argument[] =
 "option requires an argument -%s";
 
+static int strtoul_ui(char const *s, unsigned int *result)
+{
+       unsigned long ul;
+       char *p;
+
+       errno = 0;
+       ul = strtoul(s, &p, 10);
+       if (errno || *p || p == s || (unsigned int) ul != ul)
+               return -1;
+       *result = ul;
+       return 0;
+}
+
 int cmd_grep(int argc, const char **argv, const char *prefix)
 {
        int hit = 0;
@@ -553,7 +566,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                                scan = arg + 1;
                                break;
                        }
-                       if (sscanf(scan, "%u", &num) != 1)
+                       if (strtoul_ui(scan, &num))
                                die(emsg_invalid_context_len, scan);
                        switch (arg[1]) {
                        case 'A':