Merge branch 'ah/patch-id-doc'
[git] / 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(unsigned char *sha1, 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, sha1, 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         unsigned char sha1[20];
37
38         if (fstat(fd, &st) < 0 ||
39             (literally
40              ? hash_literally(sha1, fd, type, flags)
41              : index_fd(sha1, 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", sha1_to_hex(sha1));
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 }