Andrew's git - gitweb.git/blob - builtin/get-tar-commit-id.c

   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"
   9
  10static const char builtin_get_tar_commit_id_usage[] =
  11"git get-tar-commit-id < <tarfile>";
  12
  13/* ustar header + extended global header content */
  14#define RECORDSIZE      (512)
  15#define HEADERSIZE (2 * RECORDSIZE)
  16
  17int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
  18{
  19        char buffer[HEADERSIZE];
  20        struct ustar_header *header = (struct ustar_header *)buffer;
  21        char *content = buffer + RECORDSIZE;
  22        ssize_t n;
  23
  24        if (argc != 1)
  25                usage(builtin_get_tar_commit_id_usage);
  26
  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;
  34
  35        n = write_in_full(1, content + 11, 41);
  36        if (n < 41)
  37                die_errno("git get-tar-commit-id: write error");
  38
  39        return 0;
  40}