| 1 | /* |
| 2 | * Copyright (c) 2005, 2006 Rene Scharfe |
| 3 | */ |
| 4 | #include "builtin.h" |
| 5 | #include "commit.h" |
| 6 | #include "tar.h" |
| 7 | |
| 8 | static const char builtin_get_tar_commit_id_usage[] = |
| 9 | "git get-tar-commit-id"; |
| 10 | |
| 11 | /* ustar header + extended global header content */ |
| 12 | #define RECORDSIZE (512) |
| 13 | #define HEADERSIZE (2 * RECORDSIZE) |
| 14 | |
| 15 | int cmd_get_tar_commit_id(int argc, |
| 16 | const char **argv, |
| 17 | const char *prefix, |
| 18 | struct repository *repo UNUSED) |
| 19 | { |
| 20 | char buffer[HEADERSIZE]; |
| 21 | struct ustar_header *header = (struct ustar_header *)buffer; |
| 22 | char *content = buffer + RECORDSIZE; |
| 23 | const char *comment; |
| 24 | ssize_t n; |
| 25 | long len; |
| 26 | char *end; |
| 27 | |
| 28 | BUG_ON_NON_EMPTY_PREFIX(prefix); |
| 29 | |
| 30 | show_usage_if_asked(argc, argv, builtin_get_tar_commit_id_usage); |
| 31 | |
| 32 | if (argc != 1) |
| 33 | usage(builtin_get_tar_commit_id_usage); |
| 34 | |
| 35 | n = read_in_full(0, buffer, HEADERSIZE); |
| 36 | if (n < 0) |
| 37 | die_errno("git get-tar-commit-id: read error"); |
| 38 | if (n != HEADERSIZE) |
| 39 | die_errno("git get-tar-commit-id: EOF before reading tar header"); |
| 40 | if (header->typeflag[0] != TYPEFLAG_GLOBAL_HEADER) |
| 41 | return 1; |
| 42 | |
| 43 | errno = 0; |
| 44 | len = strtol(content, &end, 10); |
| 45 | if (errno == ERANGE || end == content || len < 0) |
| 46 | return 1; |
| 47 | if (!skip_prefix(end, " comment=", &comment)) |
| 48 | return 1; |
| 49 | len -= comment - content; |
| 50 | if (len < 1 || !(len % 2) || |
| 51 | hash_algo_by_length((len - 1) / 2) == GIT_HASH_UNKNOWN) |
| 52 | return 1; |
| 53 | |
| 54 | if (write_in_full(1, comment, len) < 0) |
| 55 | die_errno("git get-tar-commit-id: write error"); |
| 56 | |
| 57 | return 0; |
| 58 | } |