builtin/hash-object.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  * Copyright (C) Junio C Hamano, 2005
   6  */
   7 #include "builtin.h"
   8 #include "blob.h"
   9 #include "quote.h"
  10 #include "parse-options.h"
  11 #include "exec_cmd.h"
  12
  13 /*
  14  * This is to create corrupt objects for debugging and as such it
  15  * needs to bypass the data conversion performed by, and the type
  16  * limitation imposed by, index_fd() and its callees.
  17  */
  18 static int hash_literally(unsigned char *sha1, int fd, const char *type, unsigned flags)
  19 {
  20         struct strbuf buf = STRBUF_INIT;
  21         int ret;
  22
  23         if (strbuf_read(&buf, fd, 4096) < 0)
  24                 ret = -1;
  25         else
  26                 ret = hash_sha1_file_literally(buf.buf, buf.len, type, sha1, flags);
  27         strbuf_release(&buf);
  28         return ret;
  29 }
  30
  31 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
  32                     int literally)
  33 {
  34         struct stat st;
  35         unsigned char sha1[20];
  36
  37         if (fstat(fd, &st) < 0 ||
  38             (literally
  39              ? hash_literally(sha1, fd, type, flags)
  40              : index_fd(sha1, fd, &st, type_from_string(type), path, flags)))
  41                 die((flags & HASH_WRITE_OBJECT)
  42                     ? "Unable to add %s to database"
  43                     : "Unable to hash %s", path);
  44         printf("%s\n", sha1_to_hex(sha1));
  45         maybe_flush_or_die(stdout, "hash to stdout");
  46 }
  47
  48 static void hash_object(const char *path, const char *type, const char *vpath,
  49                         unsigned flags, int literally)
  50 {
  51         int fd;
  52         fd = open(path, O_RDONLY);
  53         if (fd < 0)
  54                 die_errno("Cannot open '%s'", path);
  55         hash_fd(fd, type, vpath, flags, literally);
  56 }
  57
  58 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
  59                              int literally)
  60 {
  61         struct strbuf buf = STRBUF_INIT, nbuf = STRBUF_INIT;
  62
  63         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
  64                 if (buf.buf[0] == '"') {
  65                         strbuf_reset(&nbuf);
  66                         if (unquote_c_style(&nbuf, buf.buf, NULL))
  67                                 die("line is badly quoted");
  68                         strbuf_swap(&buf, &nbuf);
  69                 }
  70                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
  71                             literally);
  72         }
  73         strbuf_release(&buf);
  74         strbuf_release(&nbuf);
  75 }
  76
  77 int cmd_hash_object(int argc, const char **argv, const char *prefix)
  78 {
  79         static const char * const hash_object_usage[] = {
  80                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
  81                 N_("git hash-object  --stdin-paths < <list-of-paths>"),
  82                 NULL
  83         };
  84         const char *type = blob_type;
  85         int hashstdin = 0;
  86         int stdin_paths = 0;
  87         int no_filters = 0;
  88         int literally = 0;
  89         unsigned flags = HASH_FORMAT_CHECK;
  90         const char *vpath = NULL;
  91         const struct option hash_object_options[] = {
  92                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
  93                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
  94                         HASH_WRITE_OBJECT),
  95                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
  96                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
  97                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
  98                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
  99                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
 100                 OPT_END()
 101         };
 102         int i;
 103         int prefix_length = -1;
 104         const char *errstr = NULL;
 105
 106         argc = parse_options(argc, argv, NULL, hash_object_options,
 107                              hash_object_usage, 0);
 108
 109         if (flags & HASH_WRITE_OBJECT) {
 110                 prefix = setup_git_directory();
 111                 prefix_length = prefix ? strlen(prefix) : 0;
 112                 if (vpath && prefix)
 113                         vpath = prefix_filename(prefix, prefix_length, vpath);
 114         }
 115
 116         git_config(git_default_config, NULL);
 117
 118         if (stdin_paths) {
 119                 if (hashstdin)
 120                         errstr = "Can't use --stdin-paths with --stdin";
 121                 else if (argc)
 122                         errstr = "Can't specify files with --stdin-paths";
 123                 else if (vpath)
 124                         errstr = "Can't use --stdin-paths with --path";
 125         }
 126         else {
 127                 if (hashstdin > 1)
 128                         errstr = "Multiple --stdin arguments are not supported";
 129                 if (vpath && no_filters)
 130                         errstr = "Can't use --path with --no-filters";
 131         }
 132
 133         if (errstr) {
 134                 error("%s", errstr);
 135                 usage_with_options(hash_object_usage, hash_object_options);
 136         }
 137
 138         if (hashstdin)
 139                 hash_fd(0, type, vpath, flags, literally);
 140
 141         for (i = 0 ; i < argc; i++) {
 142                 const char *arg = argv[i];
 143
 144                 if (0 <= prefix_length)
 145                         arg = prefix_filename(prefix, prefix_length, arg);
 146                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 147                             flags, literally);
 148         }
 149
 150         if (stdin_paths)
 151                 hash_stdin_paths(type, no_filters, flags, literally);
 152
 153         return 0;
 154 }