builtin/symbolic-ref.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "refs.h"
   4 #include "parse-options.h"
   5
   6 static const char * const git_symbolic_ref_usage[] = {
   7         "git symbolic-ref [options] name [ref]",
   8         NULL
   9 };
  10
  11 static int shorten;
  12
  13 static void check_symref(const char *HEAD, int quiet)
  14 {
  15         unsigned char sha1[20];
  16         int flag;
  17         const char *refname = resolve_ref_unsafe(HEAD, sha1, 0, &flag);
  18
  19         if (!refname)
  20                 die("No such ref: %s", HEAD);
  21         else if (!(flag & REF_ISSYMREF)) {
  22                 if (!quiet)
  23                         die("ref %s is not a symbolic ref", HEAD);
  24                 else
  25                         exit(1);
  26         }
  27         if (shorten)
  28                 refname = shorten_unambiguous_ref(refname, 0);
  29         puts(refname);
  30 }
  31
  32 int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
  33 {
  34         int quiet = 0;
  35         const char *msg = NULL;
  36         struct option options[] = {
  37                 OPT__QUIET(&quiet,
  38                         "suppress error message for non-symbolic (detached) refs"),
  39                 OPT_BOOL(0, "short", &shorten, "shorten ref output"),
  40                 OPT_STRING('m', NULL, &msg, "reason", "reason of the update"),
  41                 OPT_END(),
  42         };
  43
  44         git_config(git_default_config, NULL);
  45         argc = parse_options(argc, argv, prefix, options,
  46                              git_symbolic_ref_usage, 0);
  47         if (msg &&!*msg)
  48                 die("Refusing to perform update with empty message");
  49         switch (argc) {
  50         case 1:
  51                 check_symref(argv[0], quiet);
  52                 break;
  53         case 2:
  54                 if (!strcmp(argv[0], "HEAD") &&
  55                     prefixcmp(argv[1], "refs/"))
  56                         die("Refusing to point HEAD outside of refs/");
  57                 create_symref(argv[0], argv[1], msg);
  58                 break;
  59         default:
  60                 usage_with_options(git_symbolic_ref_usage, options);
  61         }
  62         return 0;
  63 }