Merge branch 'jk/reset-to-break-a-commit-doc'
[git] / 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         N_("git symbolic-ref [<options>] <name> [<ref>]"),
8         N_("git symbolic-ref -d [-q] <name>"),
9         NULL
10 };
11
12 static int check_symref(const char *HEAD, int quiet, int shorten, int print)
13 {
14         unsigned char sha1[20];
15         int flag;
16         const char *refname = resolve_ref_unsafe(HEAD, 0, sha1, &flag);
17
18         if (!refname)
19                 die("No such ref: %s", HEAD);
20         else if (!(flag & REF_ISSYMREF)) {
21                 if (!quiet)
22                         die("ref %s is not a symbolic ref", HEAD);
23                 else
24                         return 1;
25         }
26         if (print) {
27                 if (shorten)
28                         refname = shorten_unambiguous_ref(refname, 0);
29                 puts(refname);
30         }
31         return 0;
32 }
33
34 int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
35 {
36         int quiet = 0, delete = 0, shorten = 0, ret = 0;
37         const char *msg = NULL;
38         struct option options[] = {
39                 OPT__QUIET(&quiet,
40                         N_("suppress error message for non-symbolic (detached) refs")),
41                 OPT_BOOL('d', "delete", &delete, N_("delete symbolic ref")),
42                 OPT_BOOL(0, "short", &shorten, N_("shorten ref output")),
43                 OPT_STRING('m', NULL, &msg, N_("reason"), N_("reason of the update")),
44                 OPT_END(),
45         };
46
47         git_config(git_default_config, NULL);
48         argc = parse_options(argc, argv, prefix, options,
49                              git_symbolic_ref_usage, 0);
50         if (msg && !*msg)
51                 die("Refusing to perform update with empty message");
52
53         if (delete) {
54                 if (argc != 1)
55                         usage_with_options(git_symbolic_ref_usage, options);
56                 ret = check_symref(argv[0], 1, 0, 0);
57                 if (ret)
58                         die("Cannot delete %s, not a symbolic ref", argv[0]);
59                 if (!strcmp(argv[0], "HEAD"))
60                         die("deleting '%s' is not allowed", argv[0]);
61                 return delete_ref(argv[0], NULL, REF_NODEREF);
62         }
63
64         switch (argc) {
65         case 1:
66                 ret = check_symref(argv[0], quiet, shorten, 1);
67                 break;
68         case 2:
69                 if (!strcmp(argv[0], "HEAD") &&
70                     !starts_with(argv[1], "refs/"))
71                         die("Refusing to point HEAD outside of refs/");
72                 ret = !!create_symref(argv[0], argv[1], msg);
73                 break;
74         default:
75                 usage_with_options(git_symbolic_ref_usage, options);
76         }
77         return ret;
78 }