read-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 static void create_directories(const char *path)
   9 {
  10         int len = strlen(path);
  11         char *buf = malloc(len + 1);
  12         const char *slash = path;
  13
  14         while ((slash = strchr(slash+1, '/')) != NULL) {
  15                 len = slash - path;
  16                 memcpy(buf, path, len);
  17                 buf[len] = 0;
  18                 mkdir(buf, 0700);
  19         }
  20 }
  21
  22 static int create_file(const char *path)
  23 {
  24         int fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
  25         if (fd < 0) {
  26                 if (errno == ENOENT) {
  27                         create_directories(path);
  28                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0600);
  29                 }
  30         }
  31         return fd;
  32 }
  33
  34 static int unpack(unsigned char *sha1)
  35 {
  36         void *buffer;
  37         unsigned long size;
  38         char type[20];
  39
  40         buffer = read_sha1_file(sha1, type, &size);
  41         if (!buffer)
  42                 usage("unable to read sha1 file");
  43         if (strcmp(type, "tree"))
  44                 usage("expected a 'tree' node");
  45         while (size) {
  46                 int len = strlen(buffer)+1;
  47                 unsigned char *sha1 = buffer + len;
  48                 char *path = strchr(buffer, ' ')+1;
  49                 char *data;
  50                 unsigned long filesize;
  51                 unsigned int mode;
  52                 int fd;
  53
  54                 if (size < len + 20 || sscanf(buffer, "%o", &mode) != 1)
  55                         usage("corrupt 'tree' file");
  56                 buffer = sha1 + 20;
  57                 size -= len + 20;
  58                 data = read_sha1_file(sha1, type, &filesize);
  59                 if (!data || strcmp(type, "blob"))
  60                         usage("tree file refers to bad file data");
  61                 fd = create_file(path);
  62                 if (fd < 0)
  63                         usage("unable to create file");
  64                 if (write(fd, data, filesize) != filesize)
  65                         usage("unable to write file");
  66                 fchmod(fd, mode);
  67                 close(fd);
  68                 free(data);
  69         }
  70         return 0;
  71 }
  72
  73 int main(int argc, char **argv)
  74 {
  75         unsigned char sha1[20];
  76
  77         if (argc != 2)
  78                 usage("read-tree <key>");
  79         if (get_sha1_hex(argv[1], sha1) < 0)
  80                 usage("read-tree <key>");
  81         sha1_file_directory = getenv(DB_ENVIRONMENT);
  82         if (!sha1_file_directory)
  83                 sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
  84         if (unpack(sha1) < 0)
  85                 usage("unpack failed");
  86         return 0;
  87 }