Code

git-svn: documentation updates
[git.git] / builtin-update-ref.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "builtin.h"
5 static const char git_update_ref_usage[] =
6 "git-update-ref [-m <reason>] (-d <refname> <value> | <refname> <value> [<oldval>])";
8 int cmd_update_ref(int argc, const char **argv, const char *prefix)
9 {
10         const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL;
11         struct ref_lock *lock;
12         unsigned char sha1[20], oldsha1[20];
13         int i, delete;
15         delete = 0;
16         setup_ident();
17         git_config(git_default_config);
19         for (i = 1; i < argc; i++) {
20                 if (!strcmp("-m", argv[i])) {
21                         if (i+1 >= argc)
22                                 usage(git_update_ref_usage);
23                         msg = argv[++i];
24                         if (!*msg)
25                                 die("Refusing to perform update with empty message.");
26                         if (strchr(msg, '\n'))
27                                 die("Refusing to perform update with \\n in message.");
28                         continue;
29                 }
30                 if (!strcmp("-d", argv[i])) {
31                         delete = 1;
32                         continue;
33                 }
34                 if (!refname) {
35                         refname = argv[i];
36                         continue;
37                 }
38                 if (!value) {
39                         value = argv[i];
40                         continue;
41                 }
42                 if (!oldval) {
43                         oldval = argv[i];
44                         continue;
45                 }
46         }
47         if (!refname || !value)
48                 usage(git_update_ref_usage);
50         if (get_sha1(value, sha1))
51                 die("%s: not a valid SHA1", value);
53         if (delete) {
54                 if (oldval)
55                         usage(git_update_ref_usage);
56                 return delete_ref(refname, sha1);
57         }
59         hashclr(oldsha1);
60         if (oldval && *oldval && get_sha1(oldval, oldsha1))
61                 die("%s: not a valid old SHA1", oldval);
63         lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
64         if (!lock)
65                 return 1;
66         if (write_ref_sha1(lock, sha1, msg) < 0)
67                 return 1;
69         /* write_ref_sha1 always unlocks the ref, no need to do it explicitly */
70         return 0;
71 }