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_sha1_file_literally(buf.buf, buf.len, type, oid, flags);
  28         strbuf_release(&buf);
  29         return ret;
  30 }
  31
  32 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
  33                     int literally)
  34 {
  35         struct stat st;
  36         struct object_id oid;
  37
  38         if (fstat(fd, &st) < 0 ||
  39             (literally
  40              ? hash_literally(&oid, fd, type, flags)
  41              : index_fd(&oid, fd, &st, type_from_string(type), path, flags)))
  42                 die((flags & HASH_WRITE_OBJECT)
  43                     ? "Unable to add %s to database"
  44                     : "Unable to hash %s", path);
  45         printf("%s\n", oid_to_hex(&oid));
  46         maybe_flush_or_die(stdout, "hash to stdout");
  47 }
  48
  49 static void hash_object(const char *path, const char *type, const char *vpath,
  50                         unsigned flags, int literally)
  51 {
  52         int fd;
  53         fd = open(path, O_RDONLY);
  54         if (fd < 0)
  55                 die_errno("Cannot open '%s'", path);
  56         hash_fd(fd, type, vpath, flags, literally);
  57 }
  58
  59 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
  60                              int literally)
  61 {
  62         struct strbuf buf = STRBUF_INIT;
  63         struct strbuf unquoted = STRBUF_INIT;
  64
  65         while (strbuf_getline(&buf, stdin) != EOF) {
  66                 if (buf.buf[0] == '"') {
  67                         strbuf_reset(&unquoted);
  68                         if (unquote_c_style(&unquoted, buf.buf, NULL))
  69                                 die("line is badly quoted");
  70                         strbuf_swap(&buf, &unquoted);
  71                 }
  72                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
  73                             literally);
  74         }
  75         strbuf_release(&buf);
  76         strbuf_release(&unquoted);
  77 }
  78
  79 int cmd_hash_object(int argc, const char **argv, const char *prefix)
  80 {
  81         static const char * const hash_object_usage[] = {
  82                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
  83                 N_("git hash-object  --stdin-paths"),
  84                 NULL
  85         };
  86         const char *type = blob_type;
  87         int hashstdin = 0;
  88         int stdin_paths = 0;
  89         int no_filters = 0;
  90         int literally = 0;
  91         int nongit = 0;
  92         unsigned flags = HASH_FORMAT_CHECK;
  93         const char *vpath = NULL;
  94         const struct option hash_object_options[] = {
  95                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
  96                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
  97                         HASH_WRITE_OBJECT),
  98                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
  99                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
 100                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
 101                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
 102                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
 103                 OPT_END()
 104         };
 105         int i;
 106         const char *errstr = NULL;
 107
 108         argc = parse_options(argc, argv, NULL, hash_object_options,
 109                              hash_object_usage, 0);
 110
 111         if (flags & HASH_WRITE_OBJECT)
 112                 prefix = setup_git_directory();
 113         else
 114                 prefix = setup_git_directory_gently(&nongit);
 115
 116         if (vpath && prefix)
 117                 vpath = xstrdup(prefix_filename(prefix, vpath));
 118
 119         git_config(git_default_config, NULL);
 120
 121         if (stdin_paths) {
 122                 if (hashstdin)
 123                         errstr = "Can't use --stdin-paths with --stdin";
 124                 else if (argc)
 125                         errstr = "Can't specify files with --stdin-paths";
 126                 else if (vpath)
 127                         errstr = "Can't use --stdin-paths with --path";
 128         }
 129         else {
 130                 if (hashstdin > 1)
 131                         errstr = "Multiple --stdin arguments are not supported";
 132                 if (vpath && no_filters)
 133                         errstr = "Can't use --path with --no-filters";
 134         }
 135
 136         if (errstr) {
 137                 error("%s", errstr);
 138                 usage_with_options(hash_object_usage, hash_object_options);
 139         }
 140
 141         if (hashstdin)
 142                 hash_fd(0, type, vpath, flags, literally);
 143
 144         for (i = 0 ; i < argc; i++) {
 145                 const char *arg = argv[i];
 146                 char *to_free = NULL;
 147
 148                 if (prefix)
 149                         arg = to_free = prefix_filename(prefix, arg);
 150                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 151                             flags, literally);
 152                 free(to_free);
 153         }
 154
 155         if (stdin_paths)
 156                 hash_stdin_paths(type, no_filters, flags, literally);
 157
 158         return 0;
 159 }