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 "config.h"
   9 #include "blob.h"
  10 #include "quote.h"
  11 #include "parse-options.h"
  12 #include "exec-cmd.h"
  13
  14 /*
  15  * This is to create corrupt objects for debugging and as such it
  16  * needs to bypass the data conversion performed by, and the type
  17  * limitation imposed by, index_fd() and its callees.
  18  */
  19 static int hash_literally(struct object_id *oid, int fd, const char *type, unsigned flags)
  20 {
  21         struct strbuf buf = STRBUF_INIT;
  22         int ret;
  23
  24         if (strbuf_read(&buf, fd, 4096) < 0)
  25                 ret = -1;
  26         else
  27                 ret = hash_object_file_literally(buf.buf, buf.len, type, oid,
  28                                                  flags);
  29         strbuf_release(&buf);
  30         return ret;
  31 }
  32
  33 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
  34                     int literally)
  35 {
  36         struct stat st;
  37         struct object_id oid;
  38
  39         if (fstat(fd, &st) < 0 ||
  40             (literally
  41              ? hash_literally(&oid, fd, type, flags)
  42              : index_fd(&oid, fd, &st, type_from_string(type), path, flags)))
  43                 die((flags & HASH_WRITE_OBJECT)
  44                     ? "Unable to add %s to database"
  45                     : "Unable to hash %s", path);
  46         printf("%s\n", oid_to_hex(&oid));
  47         maybe_flush_or_die(stdout, "hash to stdout");
  48 }
  49
  50 static void hash_object(const char *path, const char *type, const char *vpath,
  51                         unsigned flags, int literally)
  52 {
  53         int fd;
  54         fd = open(path, O_RDONLY);
  55         if (fd < 0)
  56                 die_errno("Cannot open '%s'", path);
  57         hash_fd(fd, type, vpath, flags, literally);
  58 }
  59
  60 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
  61                              int literally)
  62 {
  63         struct strbuf buf = STRBUF_INIT;
  64         struct strbuf unquoted = STRBUF_INIT;
  65
  66         while (strbuf_getline(&buf, stdin) != EOF) {
  67                 if (buf.buf[0] == '"') {
  68                         strbuf_reset(&unquoted);
  69                         if (unquote_c_style(&unquoted, buf.buf, NULL))
  70                                 die("line is badly quoted");
  71                         strbuf_swap(&buf, &unquoted);
  72                 }
  73                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
  74                             literally);
  75         }
  76         strbuf_release(&buf);
  77         strbuf_release(&unquoted);
  78 }
  79
  80 int cmd_hash_object(int argc, const char **argv, const char *prefix)
  81 {
  82         static const char * const hash_object_usage[] = {
  83                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
  84                 N_("git hash-object  --stdin-paths"),
  85                 NULL
  86         };
  87         const char *type = blob_type;
  88         int hashstdin = 0;
  89         int stdin_paths = 0;
  90         int no_filters = 0;
  91         int literally = 0;
  92         int nongit = 0;
  93         unsigned flags = HASH_FORMAT_CHECK;
  94         const char *vpath = NULL;
  95         const struct option hash_object_options[] = {
  96                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
  97                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
  98                         HASH_WRITE_OBJECT),
  99                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
 100                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
 101                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
 102                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
 103                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
 104                 OPT_END()
 105         };
 106         int i;
 107         const char *errstr = NULL;
 108
 109         argc = parse_options(argc, argv, NULL, hash_object_options,
 110                              hash_object_usage, 0);
 111
 112         if (flags & HASH_WRITE_OBJECT)
 113                 prefix = setup_git_directory();
 114         else
 115                 prefix = setup_git_directory_gently(&nongit);
 116
 117         if (vpath && prefix)
 118                 vpath = xstrdup(prefix_filename(prefix, vpath));
 119
 120         git_config(git_default_config, NULL);
 121
 122         if (stdin_paths) {
 123                 if (hashstdin)
 124                         errstr = "Can't use --stdin-paths with --stdin";
 125                 else if (argc)
 126                         errstr = "Can't specify files with --stdin-paths";
 127                 else if (vpath)
 128                         errstr = "Can't use --stdin-paths with --path";
 129         }
 130         else {
 131                 if (hashstdin > 1)
 132                         errstr = "Multiple --stdin arguments are not supported";
 133                 if (vpath && no_filters)
 134                         errstr = "Can't use --path with --no-filters";
 135         }
 136
 137         if (errstr) {
 138                 error("%s", errstr);
 139                 usage_with_options(hash_object_usage, hash_object_options);
 140         }
 141
 142         if (hashstdin)
 143                 hash_fd(0, type, vpath, flags, literally);
 144
 145         for (i = 0 ; i < argc; i++) {
 146                 const char *arg = argv[i];
 147                 char *to_free = NULL;
 148
 149                 if (prefix)
 150                         arg = to_free = prefix_filename(prefix, arg);
 151                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 152                             flags, literally);
 153                 free(to_free);
 154         }
 155
 156         if (stdin_paths)
 157                 hash_stdin_paths(type, no_filters, flags, literally);
 158
 159         return 0;
 160 }