Merge branch 'jk/shell-portability'
[git/git.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 "builtin.h"
8 #include "parse-options.h"
9 #include "userdiff.h"
10 #include "streaming.h"
11 #include "tree-walk.h"
12 #include "sha1-array.h"
13
14 struct batch_options {
15 int enabled;
16 int follow_symlinks;
17 int print_contents;
18 int buffer_output;
19 int all_objects;
20 const char *format;
21 };
22
23 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
24 int unknown_type)
25 {
26 unsigned char sha1[20];
27 enum object_type type;
28 char *buf;
29 unsigned long size;
30 struct object_context obj_context;
31 struct object_info oi = {NULL};
32 struct strbuf sb = STRBUF_INIT;
33 unsigned flags = LOOKUP_REPLACE_OBJECT;
34
35 if (unknown_type)
36 flags |= LOOKUP_UNKNOWN_OBJECT;
37
38 if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
39 die("Not a valid object name %s", obj_name);
40
41 buf = NULL;
42 switch (opt) {
43 case 't':
44 oi.typename = &sb;
45 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
46 die("git cat-file: could not get object info");
47 if (sb.len) {
48 printf("%s\n", sb.buf);
49 strbuf_release(&sb);
50 return 0;
51 }
52 break;
53
54 case 's':
55 oi.sizep = &size;
56 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
57 die("git cat-file: could not get object info");
58 printf("%lu\n", size);
59 return 0;
60
61 case 'e':
62 return !has_sha1_file(sha1);
63
64 case 'c':
65 if (!obj_context.path[0])
66 die("git cat-file --textconv %s: <object> must be <sha1:path>",
67 obj_name);
68
69 if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
70 break;
71
72 case 'p':
73 type = sha1_object_info(sha1, NULL);
74 if (type < 0)
75 die("Not a valid object name %s", obj_name);
76
77 /* custom pretty-print here */
78 if (type == OBJ_TREE) {
79 const char *ls_args[3] = { NULL };
80 ls_args[0] = "ls-tree";
81 ls_args[1] = obj_name;
82 return cmd_ls_tree(2, ls_args, NULL);
83 }
84
85 if (type == OBJ_BLOB)
86 return stream_blob_to_fd(1, sha1, NULL, 0);
87 buf = read_sha1_file(sha1, &type, &size);
88 if (!buf)
89 die("Cannot read object %s", obj_name);
90
91 /* otherwise just spit out the data */
92 break;
93
94 case 0:
95 if (type_from_string(exp_type) == OBJ_BLOB) {
96 unsigned char blob_sha1[20];
97 if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
98 char *buffer = read_sha1_file(sha1, &type, &size);
99 const char *target;
100 if (!skip_prefix(buffer, "object ", &target) ||
101 get_sha1_hex(target, blob_sha1))
102 die("%s not a valid tag", sha1_to_hex(sha1));
103 free(buffer);
104 } else
105 hashcpy(blob_sha1, sha1);
106
107 if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
108 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
109 /*
110 * we attempted to dereference a tag to a blob
111 * and failed; there may be new dereference
112 * mechanisms this code is not aware of.
113 * fall-back to the usual case.
114 */
115 }
116 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
117 break;
118
119 default:
120 die("git cat-file: unknown option: %s", exp_type);
121 }
122
123 if (!buf)
124 die("git cat-file %s: bad file", obj_name);
125
126 write_or_die(1, buf, size);
127 return 0;
128 }
129
130 struct expand_data {
131 unsigned char sha1[20];
132 enum object_type type;
133 unsigned long size;
134 unsigned long disk_size;
135 const char *rest;
136 unsigned char delta_base_sha1[20];
137
138 /*
139 * If mark_query is true, we do not expand anything, but rather
140 * just mark the object_info with items we wish to query.
141 */
142 int mark_query;
143
144 /*
145 * Whether to split the input on whitespace before feeding it to
146 * get_sha1; this is decided during the mark_query phase based on
147 * whether we have a %(rest) token in our format.
148 */
149 int split_on_whitespace;
150
151 /*
152 * After a mark_query run, this object_info is set up to be
153 * passed to sha1_object_info_extended. It will point to the data
154 * elements above, so you can retrieve the response from there.
155 */
156 struct object_info info;
157
158 /*
159 * This flag will be true if the requested batch format and options
160 * don't require us to call sha1_object_info, which can then be
161 * optimized out.
162 */
163 unsigned skip_object_info : 1;
164 };
165
166 static int is_atom(const char *atom, const char *s, int slen)
167 {
168 int alen = strlen(atom);
169 return alen == slen && !memcmp(atom, s, alen);
170 }
171
172 static void expand_atom(struct strbuf *sb, const char *atom, int len,
173 void *vdata)
174 {
175 struct expand_data *data = vdata;
176
177 if (is_atom("objectname", atom, len)) {
178 if (!data->mark_query)
179 strbuf_addstr(sb, sha1_to_hex(data->sha1));
180 } else if (is_atom("objecttype", atom, len)) {
181 if (data->mark_query)
182 data->info.typep = &data->type;
183 else
184 strbuf_addstr(sb, typename(data->type));
185 } else if (is_atom("objectsize", atom, len)) {
186 if (data->mark_query)
187 data->info.sizep = &data->size;
188 else
189 strbuf_addf(sb, "%lu", data->size);
190 } else if (is_atom("objectsize:disk", atom, len)) {
191 if (data->mark_query)
192 data->info.disk_sizep = &data->disk_size;
193 else
194 strbuf_addf(sb, "%lu", data->disk_size);
195 } else if (is_atom("rest", atom, len)) {
196 if (data->mark_query)
197 data->split_on_whitespace = 1;
198 else if (data->rest)
199 strbuf_addstr(sb, data->rest);
200 } else if (is_atom("deltabase", atom, len)) {
201 if (data->mark_query)
202 data->info.delta_base_sha1 = data->delta_base_sha1;
203 else
204 strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
205 } else
206 die("unknown format element: %.*s", len, atom);
207 }
208
209 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
210 {
211 const char *end;
212
213 if (*start != '(')
214 return 0;
215 end = strchr(start + 1, ')');
216 if (!end)
217 die("format element '%s' does not end in ')'", start);
218
219 expand_atom(sb, start + 1, end - start - 1, data);
220
221 return end - start + 1;
222 }
223
224 static void batch_write(struct batch_options *opt, const void *data, int len)
225 {
226 if (opt->buffer_output) {
227 if (fwrite(data, 1, len, stdout) != len)
228 die_errno("unable to write to stdout");
229 } else
230 write_or_die(1, data, len);
231 }
232
233 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
234 {
235 const unsigned char *sha1 = data->sha1;
236
237 assert(data->info.typep);
238
239 if (data->type == OBJ_BLOB) {
240 if (opt->buffer_output)
241 fflush(stdout);
242 if (stream_blob_to_fd(1, sha1, NULL, 0) < 0)
243 die("unable to stream %s to stdout", sha1_to_hex(sha1));
244 }
245 else {
246 enum object_type type;
247 unsigned long size;
248 void *contents;
249
250 contents = read_sha1_file(sha1, &type, &size);
251 if (!contents)
252 die("object %s disappeared", sha1_to_hex(sha1));
253 if (type != data->type)
254 die("object %s changed type!?", sha1_to_hex(sha1));
255 if (data->info.sizep && size != data->size)
256 die("object %s changed size!?", sha1_to_hex(sha1));
257
258 batch_write(opt, contents, size);
259 free(contents);
260 }
261 }
262
263 static void batch_object_write(const char *obj_name, struct batch_options *opt,
264 struct expand_data *data)
265 {
266 struct strbuf buf = STRBUF_INIT;
267
268 if (!data->skip_object_info &&
269 sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
270 printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
271 fflush(stdout);
272 return;
273 }
274
275 strbuf_expand(&buf, opt->format, expand_format, data);
276 strbuf_addch(&buf, '\n');
277 batch_write(opt, buf.buf, buf.len);
278 strbuf_release(&buf);
279
280 if (opt->print_contents) {
281 print_object_or_die(opt, data);
282 batch_write(opt, "\n", 1);
283 }
284 }
285
286 static void batch_one_object(const char *obj_name, struct batch_options *opt,
287 struct expand_data *data)
288 {
289 struct object_context ctx;
290 int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
291 enum follow_symlinks_result result;
292
293 result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
294 if (result != FOUND) {
295 switch (result) {
296 case MISSING_OBJECT:
297 printf("%s missing\n", obj_name);
298 break;
299 case DANGLING_SYMLINK:
300 printf("dangling %"PRIuMAX"\n%s\n",
301 (uintmax_t)strlen(obj_name), obj_name);
302 break;
303 case SYMLINK_LOOP:
304 printf("loop %"PRIuMAX"\n%s\n",
305 (uintmax_t)strlen(obj_name), obj_name);
306 break;
307 case NOT_DIR:
308 printf("notdir %"PRIuMAX"\n%s\n",
309 (uintmax_t)strlen(obj_name), obj_name);
310 break;
311 default:
312 die("BUG: unknown get_sha1_with_context result %d\n",
313 result);
314 break;
315 }
316 fflush(stdout);
317 return;
318 }
319
320 if (ctx.mode == 0) {
321 printf("symlink %"PRIuMAX"\n%s\n",
322 (uintmax_t)ctx.symlink_path.len,
323 ctx.symlink_path.buf);
324 fflush(stdout);
325 return;
326 }
327
328 batch_object_write(obj_name, opt, data);
329 }
330
331 struct object_cb_data {
332 struct batch_options *opt;
333 struct expand_data *expand;
334 };
335
336 static void batch_object_cb(const unsigned char sha1[20], void *vdata)
337 {
338 struct object_cb_data *data = vdata;
339 hashcpy(data->expand->sha1, sha1);
340 batch_object_write(NULL, data->opt, data->expand);
341 }
342
343 static int batch_loose_object(const unsigned char *sha1,
344 const char *path,
345 void *data)
346 {
347 sha1_array_append(data, sha1);
348 return 0;
349 }
350
351 static int batch_packed_object(const unsigned char *sha1,
352 struct packed_git *pack,
353 uint32_t pos,
354 void *data)
355 {
356 sha1_array_append(data, sha1);
357 return 0;
358 }
359
360 static int batch_objects(struct batch_options *opt)
361 {
362 struct strbuf buf = STRBUF_INIT;
363 struct expand_data data;
364 int save_warning;
365 int retval = 0;
366
367 if (!opt->format)
368 opt->format = "%(objectname) %(objecttype) %(objectsize)";
369
370 /*
371 * Expand once with our special mark_query flag, which will prime the
372 * object_info to be handed to sha1_object_info_extended for each
373 * object.
374 */
375 memset(&data, 0, sizeof(data));
376 data.mark_query = 1;
377 strbuf_expand(&buf, opt->format, expand_format, &data);
378 data.mark_query = 0;
379
380 if (opt->all_objects) {
381 struct object_info empty;
382 memset(&empty, 0, sizeof(empty));
383 if (!memcmp(&data.info, &empty, sizeof(empty)))
384 data.skip_object_info = 1;
385 }
386
387 /*
388 * If we are printing out the object, then always fill in the type,
389 * since we will want to decide whether or not to stream.
390 */
391 if (opt->print_contents)
392 data.info.typep = &data.type;
393
394 if (opt->all_objects) {
395 struct sha1_array sa = SHA1_ARRAY_INIT;
396 struct object_cb_data cb;
397
398 for_each_loose_object(batch_loose_object, &sa, 0);
399 for_each_packed_object(batch_packed_object, &sa, 0);
400
401 cb.opt = opt;
402 cb.expand = &data;
403 sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
404
405 sha1_array_clear(&sa);
406 return 0;
407 }
408
409 /*
410 * We are going to call get_sha1 on a potentially very large number of
411 * objects. In most large cases, these will be actual object sha1s. The
412 * cost to double-check that each one is not also a ref (just so we can
413 * warn) ends up dwarfing the actual cost of the object lookups
414 * themselves. We can work around it by just turning off the warning.
415 */
416 save_warning = warn_on_object_refname_ambiguity;
417 warn_on_object_refname_ambiguity = 0;
418
419 while (strbuf_getline(&buf, stdin) != EOF) {
420 if (data.split_on_whitespace) {
421 /*
422 * Split at first whitespace, tying off the beginning
423 * of the string and saving the remainder (or NULL) in
424 * data.rest.
425 */
426 char *p = strpbrk(buf.buf, " \t");
427 if (p) {
428 while (*p && strchr(" \t", *p))
429 *p++ = '\0';
430 }
431 data.rest = p;
432 }
433
434 batch_one_object(buf.buf, opt, &data);
435 }
436
437 strbuf_release(&buf);
438 warn_on_object_refname_ambiguity = save_warning;
439 return retval;
440 }
441
442 static const char * const cat_file_usage[] = {
443 N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
444 N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
445 NULL
446 };
447
448 static int git_cat_file_config(const char *var, const char *value, void *cb)
449 {
450 if (userdiff_config(var, value) < 0)
451 return -1;
452
453 return git_default_config(var, value, cb);
454 }
455
456 static int batch_option_callback(const struct option *opt,
457 const char *arg,
458 int unset)
459 {
460 struct batch_options *bo = opt->value;
461
462 if (bo->enabled) {
463 return 1;
464 }
465
466 bo->enabled = 1;
467 bo->print_contents = !strcmp(opt->long_name, "batch");
468 bo->format = arg;
469
470 return 0;
471 }
472
473 int cmd_cat_file(int argc, const char **argv, const char *prefix)
474 {
475 int opt = 0;
476 const char *exp_type = NULL, *obj_name = NULL;
477 struct batch_options batch = {0};
478 int unknown_type = 0;
479
480 const struct option options[] = {
481 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
482 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
483 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
484 OPT_CMDMODE('e', NULL, &opt,
485 N_("exit with zero when there's no error"), 'e'),
486 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
487 OPT_CMDMODE(0, "textconv", &opt,
488 N_("for blob objects, run textconv on object's content"), 'c'),
489 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
490 N_("allow -s and -t to work with broken/corrupt objects")),
491 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
492 { OPTION_CALLBACK, 0, "batch", &batch, "format",
493 N_("show info and content of objects fed from the standard input"),
494 PARSE_OPT_OPTARG, batch_option_callback },
495 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
496 N_("show info about objects fed from the standard input"),
497 PARSE_OPT_OPTARG, batch_option_callback },
498 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
499 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
500 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
501 N_("show all objects with --batch or --batch-check")),
502 OPT_END()
503 };
504
505 git_config(git_cat_file_config, NULL);
506
507 batch.buffer_output = -1;
508 argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
509
510 if (opt) {
511 if (argc == 1)
512 obj_name = argv[0];
513 else
514 usage_with_options(cat_file_usage, options);
515 }
516 if (!opt && !batch.enabled) {
517 if (argc == 2) {
518 exp_type = argv[0];
519 obj_name = argv[1];
520 } else
521 usage_with_options(cat_file_usage, options);
522 }
523 if (batch.enabled && (opt || argc)) {
524 usage_with_options(cat_file_usage, options);
525 }
526
527 if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
528 usage_with_options(cat_file_usage, options);
529 }
530
531 if (batch.buffer_output < 0)
532 batch.buffer_output = batch.all_objects;
533
534 if (batch.enabled)
535 return batch_objects(&batch);
536
537 if (unknown_type && opt != 't' && opt != 's')
538 die("git cat-file --allow-unknown-type: use with -s or -t");
539 return cat_one_file(opt, exp_type, obj_name, unknown_type);
540 }