Merge branch 'ye/doc-http-proto' into maint
[git.git] / builtin / get-tar-commit-id.c
blobaa72596083d4e7ad9b84058e8b23b09849d74d7c
1 /*
2 * Copyright (c) 2005, 2006 Rene Scharfe
3 */
4 #include "cache.h"
5 #include "commit.h"
6 #include "tar.h"
7 #include "builtin.h"
8 #include "quote.h"
10 static const char builtin_get_tar_commit_id_usage[] =
11 "git get-tar-commit-id < <tarfile>";
13 /* ustar header + extended global header content */
14 #define RECORDSIZE (512)
15 #define HEADERSIZE (2 * RECORDSIZE)
17 int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
19 char buffer[HEADERSIZE];
20 struct ustar_header *header = (struct ustar_header *)buffer;
21 char *content = buffer + RECORDSIZE;
22 ssize_t n;
24 if (argc != 1)
25 usage(builtin_get_tar_commit_id_usage);
27 n = read_in_full(0, buffer, HEADERSIZE);
28 if (n < HEADERSIZE)
29 die("git get-tar-commit-id: read error");
30 if (header->typeflag[0] != 'g')
31 return 1;
32 if (memcmp(content, "52 comment=", 11))
33 return 1;
35 n = write_in_full(1, content + 11, 41);
36 if (n < 41)
37 die_errno("git get-tar-commit-id: write error");
39 return 0;