builtin-grep: allow -<n> and -[ABC]<n> notation for context lines.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-grep.c b/builtin-grep.c
index eb821b4..a551d34 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -402,18 +402,34 @@ int cmd_grep(int argc, const char **argv, char **envp)
                        opt.name_only = 1;
                        continue;
                }
-               if (!strcmp("-A", arg) ||
-                   !strcmp("-B", arg) ||
-                   !strcmp("-C", arg)) {
+               if (!strncmp("-A", arg, 2) ||
+                   !strncmp("-B", arg, 2) ||
+                   !strncmp("-C", arg, 2) ||
+                   (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
                        unsigned num;
-                       if (argc <= 1 ||
-                           sscanf(*++argv, "%u", &num) != 1)
+                       const char *scan;
+                       switch (arg[1]) {
+                       case 'A': case 'B': case 'C':
+                               if (!arg[2]) {
+                                       if (argc <= 1)
+                                               usage(builtin_grep_usage);
+                                       scan = *++argv;
+                                       argc--;
+                               }
+                               else
+                                       scan = arg + 2;
+                               break;
+                       default:
+                               scan = arg + 1;
+                               break;
+                       }
+                       if (sscanf(scan, "%u", &num) != 1)
                                usage(builtin_grep_usage);
-                       argc--;
                        switch (arg[1]) {
                        case 'A':
                                opt.post_context = num;
                                break;
+                       default:
                        case 'C':
                                opt.post_context = num;
                        case 'B':