update-ref.c

   1 #include "cache.h"
   2 #include "refs.h"
   3
   4 static const char git_update_ref_usage[] =
   5 "git-update-ref <refname> <value> [<oldval>] [-m <reason>]";
   6
   7 int main(int argc, char **argv)
   8 {
   9         const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL;
  10         struct ref_lock *lock;
  11         unsigned char sha1[20], oldsha1[20];
  12         int i;
  13
  14         setup_git_directory();
  15         git_config(git_default_config);
  16
  17         for (i = 1; i < argc; i++) {
  18                 if (!strcmp("-m", argv[i])) {
  19                         if (i+1 >= argc)
  20                                 usage(git_update_ref_usage);
  21                         msg = argv[++i];
  22                         if (!*msg)
  23                                 die("Refusing to perform update with empty message.");
  24                         if (strchr(msg, '\n'))
  25                                 die("Refusing to perform update with \\n in message.");
  26                         continue;
  27                 }
  28                 if (!refname) {
  29                         refname = argv[i];
  30                         continue;
  31                 }
  32                 if (!value) {
  33                         value = argv[i];
  34                         continue;
  35                 }
  36                 if (!oldval) {
  37                         oldval = argv[i];
  38                         continue;
  39                 }
  40         }
  41         if (!refname || !value)
  42                 usage(git_update_ref_usage);
  43
  44         if (get_sha1(value, sha1))
  45                 die("%s: not a valid SHA1", value);
  46         memset(oldsha1, 0, 20);
  47         if (oldval && get_sha1(oldval, oldsha1))
  48                 die("%s: not a valid old SHA1", oldval);
  49
  50         lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL, 0);
  51         if (!lock)
  52                 return 1;
  53         if (write_ref_sha1(lock, sha1, msg) < 0)
  54                 return 1;
  55         return 0;
  56 }