Builtin git-init-db
[git] / cat-file.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "cache.h"
7 #include "exec_cmd.h"
8 #include "tag.h"
9 #include "tree.h"
10
11 static void flush_buffer(const char *buf, unsigned long size)
12 {
13         while (size > 0) {
14                 long ret = xwrite(1, buf, size);
15                 if (ret < 0) {
16                         /* Ignore epipe */
17                         if (errno == EPIPE)
18                                 break;
19                         die("git-cat-file: %s", strerror(errno));
20                 } else if (!ret) {
21                         die("git-cat-file: disk full?");
22                 }
23                 size -= ret;
24                 buf += ret;
25         }
26 }
27
28 static int pprint_tag(const unsigned char *sha1, const char *buf, unsigned long size)
29 {
30         /* the parser in tag.c is useless here. */
31         const char *endp = buf + size;
32         const char *cp = buf;
33
34         while (cp < endp) {
35                 char c = *cp++;
36                 if (c != '\n')
37                         continue;
38                 if (7 <= endp - cp && !memcmp("tagger ", cp, 7)) {
39                         const char *tagger = cp;
40
41                         /* Found the tagger line.  Copy out the contents
42                          * of the buffer so far.
43                          */
44                         flush_buffer(buf, cp - buf);
45
46                         /*
47                          * Do something intelligent, like pretty-printing
48                          * the date.
49                          */
50                         while (cp < endp) {
51                                 if (*cp++ == '\n') {
52                                         /* tagger to cp is a line
53                                          * that has ident and time.
54                                          */
55                                         const char *sp = tagger;
56                                         char *ep;
57                                         unsigned long date;
58                                         long tz;
59                                         while (sp < cp && *sp != '>')
60                                                 sp++;
61                                         if (sp == cp) {
62                                                 /* give up */
63                                                 flush_buffer(tagger,
64                                                              cp - tagger);
65                                                 break;
66                                         }
67                                         while (sp < cp &&
68                                                !('0' <= *sp && *sp <= '9'))
69                                                 sp++;
70                                         flush_buffer(tagger, sp - tagger);
71                                         date = strtoul(sp, &ep, 10);
72                                         tz = strtol(ep, NULL, 10);
73                                         sp = show_date(date, tz);
74                                         flush_buffer(sp, strlen(sp));
75                                         xwrite(1, "\n", 1);
76                                         break;
77                                 }
78                         }
79                         break;
80                 }
81                 if (cp < endp && *cp == '\n')
82                         /* end of header */
83                         break;
84         }
85         /* At this point, we have copied out the header up to the end of
86          * the tagger line and cp points at one past \n.  It could be the
87          * next header line after the tagger line, or it could be another
88          * \n that marks the end of the headers.  We need to copy out the
89          * remainder as is.
90          */
91         if (cp < endp)
92                 flush_buffer(cp, endp - cp);
93         return 0;
94 }
95
96 int main(int argc, char **argv)
97 {
98         unsigned char sha1[20];
99         char type[20];
100         void *buf;
101         unsigned long size;
102         int opt;
103
104         setup_git_directory();
105         git_config(git_default_config);
106         if (argc != 3)
107                 usage("git-cat-file [-t|-s|-e|-p|<type>] <sha1>");
108         if (get_sha1(argv[2], sha1))
109                 die("Not a valid object name %s", argv[2]);
110
111         opt = 0;
112         if ( argv[1][0] == '-' ) {
113                 opt = argv[1][1];
114                 if ( !opt || argv[1][2] )
115                         opt = -1; /* Not a single character option */
116         }
117
118         buf = NULL;
119         switch (opt) {
120         case 't':
121                 if (!sha1_object_info(sha1, type, NULL)) {
122                         printf("%s\n", type);
123                         return 0;
124                 }
125                 break;
126
127         case 's':
128                 if (!sha1_object_info(sha1, type, &size)) {
129                         printf("%lu\n", size);
130                         return 0;
131                 }
132                 break;
133
134         case 'e':
135                 return !has_sha1_file(sha1);
136
137         case 'p':
138                 if (sha1_object_info(sha1, type, NULL))
139                         die("Not a valid object name %s", argv[2]);
140
141                 /* custom pretty-print here */
142                 if (!strcmp(type, tree_type))
143                         return execl_git_cmd("ls-tree", argv[2], NULL);
144
145                 buf = read_sha1_file(sha1, type, &size);
146                 if (!buf)
147                         die("Cannot read object %s", argv[2]);
148                 if (!strcmp(type, tag_type))
149                         return pprint_tag(sha1, buf, size);
150
151                 /* otherwise just spit out the data */
152                 break;
153         case 0:
154                 buf = read_object_with_reference(sha1, argv[1], &size, NULL);
155                 break;
156
157         default:
158                 die("git-cat-file: unknown option: %s\n", argv[1]);
159         }
160
161         if (!buf)
162                 die("git-cat-file %s: bad file", argv[2]);
163
164         flush_buffer(buf, size);
165         return 0;
166 }