Merge branch 'fc/remote-helper-fixes'
[git] / builtin / 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 #include "builtin.h"
11 #include "parse-options.h"
12 #include "diff.h"
13 #include "userdiff.h"
14 #include "streaming.h"
15
16 static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
17 {
18         unsigned char sha1[20];
19         enum object_type type;
20         char *buf;
21         unsigned long size;
22         struct object_context obj_context;
23
24         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
25                 die("Not a valid object name %s", obj_name);
26
27         buf = NULL;
28         switch (opt) {
29         case 't':
30                 type = sha1_object_info(sha1, NULL);
31                 if (type > 0) {
32                         printf("%s\n", typename(type));
33                         return 0;
34                 }
35                 break;
36
37         case 's':
38                 type = sha1_object_info(sha1, &size);
39                 if (type > 0) {
40                         printf("%lu\n", size);
41                         return 0;
42                 }
43                 break;
44
45         case 'e':
46                 return !has_sha1_file(sha1);
47
48         case 'c':
49                 if (!obj_context.path[0])
50                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
51                             obj_name);
52
53                 if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
54                         break;
55
56         case 'p':
57                 type = sha1_object_info(sha1, NULL);
58                 if (type < 0)
59                         die("Not a valid object name %s", obj_name);
60
61                 /* custom pretty-print here */
62                 if (type == OBJ_TREE) {
63                         const char *ls_args[3] = { NULL };
64                         ls_args[0] =  "ls-tree";
65                         ls_args[1] =  obj_name;
66                         return cmd_ls_tree(2, ls_args, NULL);
67                 }
68
69                 if (type == OBJ_BLOB)
70                         return stream_blob_to_fd(1, sha1, NULL, 0);
71                 buf = read_sha1_file(sha1, &type, &size);
72                 if (!buf)
73                         die("Cannot read object %s", obj_name);
74
75                 /* otherwise just spit out the data */
76                 break;
77
78         case 0:
79                 if (type_from_string(exp_type) == OBJ_BLOB) {
80                         unsigned char blob_sha1[20];
81                         if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
82                                 enum object_type type;
83                                 unsigned long size;
84                                 char *buffer = read_sha1_file(sha1, &type, &size);
85                                 if (memcmp(buffer, "object ", 7) ||
86                                     get_sha1_hex(buffer + 7, blob_sha1))
87                                         die("%s not a valid tag", sha1_to_hex(sha1));
88                                 free(buffer);
89                         } else
90                                 hashcpy(blob_sha1, sha1);
91
92                         if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
93                                 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
94                         /*
95                          * we attempted to dereference a tag to a blob
96                          * and failed; there may be new dereference
97                          * mechanisms this code is not aware of.
98                          * fall-back to the usual case.
99                          */
100                 }
101                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
102                 break;
103
104         default:
105                 die("git cat-file: unknown option: %s", exp_type);
106         }
107
108         if (!buf)
109                 die("git cat-file %s: bad file", obj_name);
110
111         write_or_die(1, buf, size);
112         return 0;
113 }
114
115 struct expand_data {
116         unsigned char sha1[20];
117         enum object_type type;
118         unsigned long size;
119         unsigned long disk_size;
120         const char *rest;
121
122         /*
123          * If mark_query is true, we do not expand anything, but rather
124          * just mark the object_info with items we wish to query.
125          */
126         int mark_query;
127
128         /*
129          * Whether to split the input on whitespace before feeding it to
130          * get_sha1; this is decided during the mark_query phase based on
131          * whether we have a %(rest) token in our format.
132          */
133         int split_on_whitespace;
134
135         /*
136          * After a mark_query run, this object_info is set up to be
137          * passed to sha1_object_info_extended. It will point to the data
138          * elements above, so you can retrieve the response from there.
139          */
140         struct object_info info;
141 };
142
143 static int is_atom(const char *atom, const char *s, int slen)
144 {
145         int alen = strlen(atom);
146         return alen == slen && !memcmp(atom, s, alen);
147 }
148
149 static void expand_atom(struct strbuf *sb, const char *atom, int len,
150                         void *vdata)
151 {
152         struct expand_data *data = vdata;
153
154         if (is_atom("objectname", atom, len)) {
155                 if (!data->mark_query)
156                         strbuf_addstr(sb, sha1_to_hex(data->sha1));
157         } else if (is_atom("objecttype", atom, len)) {
158                 if (data->mark_query)
159                         data->info.typep = &data->type;
160                 else
161                         strbuf_addstr(sb, typename(data->type));
162         } else if (is_atom("objectsize", atom, len)) {
163                 if (data->mark_query)
164                         data->info.sizep = &data->size;
165                 else
166                         strbuf_addf(sb, "%lu", data->size);
167         } else if (is_atom("objectsize:disk", atom, len)) {
168                 if (data->mark_query)
169                         data->info.disk_sizep = &data->disk_size;
170                 else
171                         strbuf_addf(sb, "%lu", data->disk_size);
172         } else if (is_atom("rest", atom, len)) {
173                 if (data->mark_query)
174                         data->split_on_whitespace = 1;
175                 else if (data->rest)
176                         strbuf_addstr(sb, data->rest);
177         } else
178                 die("unknown format element: %.*s", len, atom);
179 }
180
181 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
182 {
183         const char *end;
184
185         if (*start != '(')
186                 return 0;
187         end = strchr(start + 1, ')');
188         if (!end)
189                 die("format element '%s' does not end in ')'", start);
190
191         expand_atom(sb, start + 1, end - start - 1, data);
192
193         return end - start + 1;
194 }
195
196 static void print_object_or_die(int fd, struct expand_data *data)
197 {
198         const unsigned char *sha1 = data->sha1;
199
200         assert(data->info.typep);
201
202         if (data->type == OBJ_BLOB) {
203                 if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
204                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
205         }
206         else {
207                 enum object_type type;
208                 unsigned long size;
209                 void *contents;
210
211                 contents = read_sha1_file(sha1, &type, &size);
212                 if (!contents)
213                         die("object %s disappeared", sha1_to_hex(sha1));
214                 if (type != data->type)
215                         die("object %s changed type!?", sha1_to_hex(sha1));
216                 if (data->info.sizep && size != data->size)
217                         die("object %s changed size!?", sha1_to_hex(sha1));
218
219                 write_or_die(fd, contents, size);
220                 free(contents);
221         }
222 }
223
224 struct batch_options {
225         int enabled;
226         int print_contents;
227         const char *format;
228 };
229
230 static int batch_one_object(const char *obj_name, struct batch_options *opt,
231                             struct expand_data *data)
232 {
233         struct strbuf buf = STRBUF_INIT;
234
235         if (!obj_name)
236            return 1;
237
238         if (get_sha1(obj_name, data->sha1)) {
239                 printf("%s missing\n", obj_name);
240                 fflush(stdout);
241                 return 0;
242         }
243
244         if (sha1_object_info_extended(data->sha1, &data->info) < 0) {
245                 printf("%s missing\n", obj_name);
246                 fflush(stdout);
247                 return 0;
248         }
249
250         strbuf_expand(&buf, opt->format, expand_format, data);
251         strbuf_addch(&buf, '\n');
252         write_or_die(1, buf.buf, buf.len);
253         strbuf_release(&buf);
254
255         if (opt->print_contents) {
256                 print_object_or_die(1, data);
257                 write_or_die(1, "\n", 1);
258         }
259         return 0;
260 }
261
262 static int batch_objects(struct batch_options *opt)
263 {
264         struct strbuf buf = STRBUF_INIT;
265         struct expand_data data;
266
267         if (!opt->format)
268                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
269
270         /*
271          * Expand once with our special mark_query flag, which will prime the
272          * object_info to be handed to sha1_object_info_extended for each
273          * object.
274          */
275         memset(&data, 0, sizeof(data));
276         data.mark_query = 1;
277         strbuf_expand(&buf, opt->format, expand_format, &data);
278         data.mark_query = 0;
279
280         /*
281          * If we are printing out the object, then always fill in the type,
282          * since we will want to decide whether or not to stream.
283          */
284         if (opt->print_contents)
285                 data.info.typep = &data.type;
286
287         /*
288          * We are going to call get_sha1 on a potentially very large number of
289          * objects. In most large cases, these will be actual object sha1s. The
290          * cost to double-check that each one is not also a ref (just so we can
291          * warn) ends up dwarfing the actual cost of the object lookups
292          * themselves. We can work around it by just turning off the warning.
293          */
294         warn_on_object_refname_ambiguity = 0;
295
296         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
297                 int error;
298
299                 if (data.split_on_whitespace) {
300                         /*
301                          * Split at first whitespace, tying off the beginning
302                          * of the string and saving the remainder (or NULL) in
303                          * data.rest.
304                          */
305                         char *p = strpbrk(buf.buf, " \t");
306                         if (p) {
307                                 while (*p && strchr(" \t", *p))
308                                         *p++ = '\0';
309                         }
310                         data.rest = p;
311                 }
312
313                 error = batch_one_object(buf.buf, opt, &data);
314                 if (error)
315                         return error;
316         }
317
318         return 0;
319 }
320
321 static const char * const cat_file_usage[] = {
322         N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
323         N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
324         NULL
325 };
326
327 static int git_cat_file_config(const char *var, const char *value, void *cb)
328 {
329         if (userdiff_config(var, value) < 0)
330                 return -1;
331
332         return git_default_config(var, value, cb);
333 }
334
335 static int batch_option_callback(const struct option *opt,
336                                  const char *arg,
337                                  int unset)
338 {
339         struct batch_options *bo = opt->value;
340
341         if (unset) {
342                 memset(bo, 0, sizeof(*bo));
343                 return 0;
344         }
345
346         bo->enabled = 1;
347         bo->print_contents = !strcmp(opt->long_name, "batch");
348         bo->format = arg;
349
350         return 0;
351 }
352
353 int cmd_cat_file(int argc, const char **argv, const char *prefix)
354 {
355         int opt = 0;
356         const char *exp_type = NULL, *obj_name = NULL;
357         struct batch_options batch = {0};
358
359         const struct option options[] = {
360                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
361                 OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
362                 OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
363                 OPT_SET_INT('e', NULL, &opt,
364                             N_("exit with zero when there's no error"), 'e'),
365                 OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
366                 OPT_SET_INT(0, "textconv", &opt,
367                             N_("for blob objects, run textconv on object's content"), 'c'),
368                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
369                         N_("show info and content of objects fed from the standard input"),
370                         PARSE_OPT_OPTARG, batch_option_callback },
371                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
372                         N_("show info about objects fed from the standard input"),
373                         PARSE_OPT_OPTARG, batch_option_callback },
374                 OPT_END()
375         };
376
377         git_config(git_cat_file_config, NULL);
378
379         if (argc != 3 && argc != 2)
380                 usage_with_options(cat_file_usage, options);
381
382         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
383
384         if (opt) {
385                 if (argc == 1)
386                         obj_name = argv[0];
387                 else
388                         usage_with_options(cat_file_usage, options);
389         }
390         if (!opt && !batch.enabled) {
391                 if (argc == 2) {
392                         exp_type = argv[0];
393                         obj_name = argv[1];
394                 } else
395                         usage_with_options(cat_file_usage, options);
396         }
397         if (batch.enabled && (opt || argc)) {
398                 usage_with_options(cat_file_usage, options);
399         }
400
401         if (batch.enabled)
402                 return batch_objects(&batch);
403
404         return cat_one_file(opt, exp_type, obj_name);
405 }