Miscellaneous const changes and utilities
[git/dscho.git] / builtin-cat-file.c
blobf132d583d3e2a2ac0fe696b66723c846902d0a19
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 #include "builtin.h"
12 static void pprint_tag(const unsigned char *sha1, const char *buf, unsigned long size)
14         /* the parser in tag.c is useless here. */
15         const char *endp = buf + size;
16         const char *cp = buf;
18         while (cp < endp) {
19                 char c = *cp++;
20                 if (c != '\n')
21                         continue;
22                 if (7 <= endp - cp && !memcmp("tagger ", cp, 7)) {
23                         const char *tagger = cp;
25                         /* Found the tagger line.  Copy out the contents
26                          * of the buffer so far.
27                          */
28                         write_or_die(1, buf, cp - buf);
30                         /*
31                          * Do something intelligent, like pretty-printing
32                          * the date.
33                          */
34                         while (cp < endp) {
35                                 if (*cp++ == '\n') {
36                                         /* tagger to cp is a line
37                                          * that has ident and time.
38                                          */
39                                         const char *sp = tagger;
40                                         char *ep;
41                                         unsigned long date;
42                                         long tz;
43                                         while (sp < cp && *sp != '>')
44                                                 sp++;
45                                         if (sp == cp) {
46                                                 /* give up */
47                                                 write_or_die(1, tagger,
48                                                              cp - tagger);
49                                                 break;
50                                         }
51                                         while (sp < cp &&
52                                                !('0' <= *sp && *sp <= '9'))
53                                                 sp++;
54                                         write_or_die(1, tagger, sp - tagger);
55                                         date = strtoul(sp, &ep, 10);
56                                         tz = strtol(ep, NULL, 10);
57                                         sp = show_date(date, tz, 0);
58                                         write_or_die(1, sp, strlen(sp));
59                                         xwrite(1, "\n", 1);
60                                         break;
61                                 }
62                         }
63                         break;
64                 }
65                 if (cp < endp && *cp == '\n')
66                         /* end of header */
67                         break;
68         }
69         /* At this point, we have copied out the header up to the end of
70          * the tagger line and cp points at one past \n.  It could be the
71          * next header line after the tagger line, or it could be another
72          * \n that marks the end of the headers.  We need to copy out the
73          * remainder as is.
74          */
75         if (cp < endp)
76                 write_or_die(1, cp, endp - cp);
79 int cmd_cat_file(int argc, const char **argv, const char *prefix)
81         unsigned char sha1[20];
82         enum object_type type;
83         void *buf;
84         unsigned long size;
85         int opt;
86         const char *exp_type, *obj_name;
88         git_config(git_default_config);
89         if (argc != 3)
90                 usage("git-cat-file [-t|-s|-e|-p|<type>] <sha1>");
91         exp_type = argv[1];
92         obj_name = argv[2];
94         if (get_sha1(obj_name, sha1))
95                 die("Not a valid object name %s", obj_name);
97         opt = 0;
98         if ( exp_type[0] == '-' ) {
99                 opt = exp_type[1];
100                 if ( !opt || exp_type[2] )
101                         opt = -1; /* Not a single character option */
102         }
104         buf = NULL;
105         switch (opt) {
106         case 't':
107                 type = sha1_object_info(sha1, NULL);
108                 if (type > 0) {
109                         printf("%s\n", typename(type));
110                         return 0;
111                 }
112                 break;
114         case 's':
115                 type = sha1_object_info(sha1, &size);
116                 if (type > 0) {
117                         printf("%lu\n", size);
118                         return 0;
119                 }
120                 break;
122         case 'e':
123                 return !has_sha1_file(sha1);
125         case 'p':
126                 type = sha1_object_info(sha1, NULL);
127                 if (type < 0)
128                         die("Not a valid object name %s", obj_name);
130                 /* custom pretty-print here */
131                 if (type == OBJ_TREE) {
132                         const char *ls_args[3] = {"ls-tree", obj_name, NULL};
133                         return cmd_ls_tree(2, ls_args, NULL);
134                 }
136                 buf = read_sha1_file(sha1, &type, &size);
137                 if (!buf)
138                         die("Cannot read object %s", obj_name);
139                 if (type == OBJ_TAG) {
140                         pprint_tag(sha1, buf, size);
141                         return 0;
142                 }
144                 /* otherwise just spit out the data */
145                 break;
146         case 0:
147                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
148                 break;
150         default:
151                 die("git-cat-file: unknown option: %s\n", exp_type);
152         }
154         if (!buf)
155                 die("git-cat-file %s: bad file", obj_name);
157         write_or_die(1, buf, size);
158         return 0;