format-patch: teach --cover-from-description option
[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 "object-store.h"
10 #include "blob.h"
11 #include "quote.h"
12 #include "parse-options.h"
13 #include "exec-cmd.h"
14
15 /*
16  * This is to create corrupt objects for debugging and as such it
17  * needs to bypass the data conversion performed by, and the type
18  * limitation imposed by, index_fd() and its callees.
19  */
20 static int hash_literally(struct object_id *oid, int fd, const char *type, unsigned flags)
21 {
22         struct strbuf buf = STRBUF_INIT;
23         int ret;
24
25         if (strbuf_read(&buf, fd, 4096) < 0)
26                 ret = -1;
27         else
28                 ret = hash_object_file_literally(buf.buf, buf.len, type, oid,
29                                                  flags);
30         strbuf_release(&buf);
31         return ret;
32 }
33
34 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
35                     int literally)
36 {
37         struct stat st;
38         struct object_id oid;
39
40         if (fstat(fd, &st) < 0 ||
41             (literally
42              ? hash_literally(&oid, fd, type, flags)
43              : index_fd(the_repository->index, &oid, fd, &st,
44                         type_from_string(type), path, flags)))
45                 die((flags & HASH_WRITE_OBJECT)
46                     ? "Unable to add %s to database"
47                     : "Unable to hash %s", path);
48         printf("%s\n", oid_to_hex(&oid));
49         maybe_flush_or_die(stdout, "hash to stdout");
50 }
51
52 static void hash_object(const char *path, const char *type, const char *vpath,
53                         unsigned flags, int literally)
54 {
55         int fd;
56         fd = open(path, O_RDONLY);
57         if (fd < 0)
58                 die_errno("Cannot open '%s'", path);
59         hash_fd(fd, type, vpath, flags, literally);
60 }
61
62 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
63                              int literally)
64 {
65         struct strbuf buf = STRBUF_INIT;
66         struct strbuf unquoted = STRBUF_INIT;
67
68         while (strbuf_getline(&buf, stdin) != EOF) {
69                 if (buf.buf[0] == '"') {
70                         strbuf_reset(&unquoted);
71                         if (unquote_c_style(&unquoted, buf.buf, NULL))
72                                 die("line is badly quoted");
73                         strbuf_swap(&buf, &unquoted);
74                 }
75                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
76                             literally);
77         }
78         strbuf_release(&buf);
79         strbuf_release(&unquoted);
80 }
81
82 int cmd_hash_object(int argc, const char **argv, const char *prefix)
83 {
84         static const char * const hash_object_usage[] = {
85                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters] [--stdin] [--] <file>..."),
86                 N_("git hash-object  --stdin-paths"),
87                 NULL
88         };
89         const char *type = blob_type;
90         int hashstdin = 0;
91         int stdin_paths = 0;
92         int no_filters = 0;
93         int literally = 0;
94         int nongit = 0;
95         unsigned flags = HASH_FORMAT_CHECK;
96         const char *vpath = NULL;
97         const struct option hash_object_options[] = {
98                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
99                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
100                         HASH_WRITE_OBJECT),
101                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
102                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
103                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
104                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
105                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
106                 OPT_END()
107         };
108         int i;
109         const char *errstr = NULL;
110
111         argc = parse_options(argc, argv, prefix, hash_object_options,
112                              hash_object_usage, 0);
113
114         if (flags & HASH_WRITE_OBJECT)
115                 prefix = setup_git_directory();
116         else
117                 prefix = setup_git_directory_gently(&nongit);
118
119         if (vpath && prefix)
120                 vpath = xstrdup(prefix_filename(prefix, vpath));
121
122         git_config(git_default_config, NULL);
123
124         if (stdin_paths) {
125                 if (hashstdin)
126                         errstr = "Can't use --stdin-paths with --stdin";
127                 else if (argc)
128                         errstr = "Can't specify files with --stdin-paths";
129                 else if (vpath)
130                         errstr = "Can't use --stdin-paths with --path";
131         }
132         else {
133                 if (hashstdin > 1)
134                         errstr = "Multiple --stdin arguments are not supported";
135                 if (vpath && no_filters)
136                         errstr = "Can't use --path with --no-filters";
137         }
138
139         if (errstr) {
140                 error("%s", errstr);
141                 usage_with_options(hash_object_usage, hash_object_options);
142         }
143
144         if (hashstdin)
145                 hash_fd(0, type, vpath, flags, literally);
146
147         for (i = 0 ; i < argc; i++) {
148                 const char *arg = argv[i];
149                 char *to_free = NULL;
150
151                 if (prefix)
152                         arg = to_free = prefix_filename(prefix, arg);
153                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
154                             flags, literally);
155                 free(to_free);
156         }
157
158         if (stdin_paths)
159                 hash_stdin_paths(type, no_filters, flags, literally);
160
161         return 0;
162 }