t2300: run git-sh-setup in an environment that better mimics the real life
[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 static int is_atom(const char *atom, const char *s, int slen)
160 {
161 int alen = strlen(atom);
162 return alen == slen && !memcmp(atom, s, alen);
163 }
164
165 static void expand_atom(struct strbuf *sb, const char *atom, int len,
166 void *vdata)
167 {
168 struct expand_data *data = vdata;
169
170 if (is_atom("objectname", atom, len)) {
171 if (!data->mark_query)
172 strbuf_addstr(sb, sha1_to_hex(data->sha1));
173 } else if (is_atom("objecttype", atom, len)) {
174 if (data->mark_query)
175 data->info.typep = &data->type;
176 else
177 strbuf_addstr(sb, typename(data->type));
178 } else if (is_atom("objectsize", atom, len)) {
179 if (data->mark_query)
180 data->info.sizep = &data->size;
181 else
182 strbuf_addf(sb, "%lu", data->size);
183 } else if (is_atom("objectsize:disk", atom, len)) {
184 if (data->mark_query)
185 data->info.disk_sizep = &data->disk_size;
186 else
187 strbuf_addf(sb, "%lu", data->disk_size);
188 } else if (is_atom("rest", atom, len)) {
189 if (data->mark_query)
190 data->split_on_whitespace = 1;
191 else if (data->rest)
192 strbuf_addstr(sb, data->rest);
193 } else if (is_atom("deltabase", atom, len)) {
194 if (data->mark_query)
195 data->info.delta_base_sha1 = data->delta_base_sha1;
196 else
197 strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
198 } else
199 die("unknown format element: %.*s", len, atom);
200 }
201
202 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
203 {
204 const char *end;
205
206 if (*start != '(')
207 return 0;
208 end = strchr(start + 1, ')');
209 if (!end)
210 die("format element '%s' does not end in ')'", start);
211
212 expand_atom(sb, start + 1, end - start - 1, data);
213
214 return end - start + 1;
215 }
216
217 static void batch_write(struct batch_options *opt, const void *data, int len)
218 {
219 if (opt->buffer_output) {
220 if (fwrite(data, 1, len, stdout) != len)
221 die_errno("unable to write to stdout");
222 } else
223 write_or_die(1, data, len);
224 }
225
226 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
227 {
228 const unsigned char *sha1 = data->sha1;
229
230 assert(data->info.typep);
231
232 if (data->type == OBJ_BLOB) {
233 if (opt->buffer_output)
234 fflush(stdout);
235 if (stream_blob_to_fd(1, sha1, NULL, 0) < 0)
236 die("unable to stream %s to stdout", sha1_to_hex(sha1));
237 }
238 else {
239 enum object_type type;
240 unsigned long size;
241 void *contents;
242
243 contents = read_sha1_file(sha1, &type, &size);
244 if (!contents)
245 die("object %s disappeared", sha1_to_hex(sha1));
246 if (type != data->type)
247 die("object %s changed type!?", sha1_to_hex(sha1));
248 if (data->info.sizep && size != data->size)
249 die("object %s changed size!?", sha1_to_hex(sha1));
250
251 batch_write(opt, contents, size);
252 free(contents);
253 }
254 }
255
256 static void batch_object_write(const char *obj_name, struct batch_options *opt,
257 struct expand_data *data)
258 {
259 struct strbuf buf = STRBUF_INIT;
260
261 if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
262 printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
263 fflush(stdout);
264 return;
265 }
266
267 strbuf_expand(&buf, opt->format, expand_format, data);
268 strbuf_addch(&buf, '\n');
269 batch_write(opt, buf.buf, buf.len);
270 strbuf_release(&buf);
271
272 if (opt->print_contents) {
273 print_object_or_die(opt, data);
274 batch_write(opt, "\n", 1);
275 }
276 }
277
278 static void batch_one_object(const char *obj_name, struct batch_options *opt,
279 struct expand_data *data)
280 {
281 struct object_context ctx;
282 int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
283 enum follow_symlinks_result result;
284
285 result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
286 if (result != FOUND) {
287 switch (result) {
288 case MISSING_OBJECT:
289 printf("%s missing\n", obj_name);
290 break;
291 case DANGLING_SYMLINK:
292 printf("dangling %"PRIuMAX"\n%s\n",
293 (uintmax_t)strlen(obj_name), obj_name);
294 break;
295 case SYMLINK_LOOP:
296 printf("loop %"PRIuMAX"\n%s\n",
297 (uintmax_t)strlen(obj_name), obj_name);
298 break;
299 case NOT_DIR:
300 printf("notdir %"PRIuMAX"\n%s\n",
301 (uintmax_t)strlen(obj_name), obj_name);
302 break;
303 default:
304 die("BUG: unknown get_sha1_with_context result %d\n",
305 result);
306 break;
307 }
308 fflush(stdout);
309 return;
310 }
311
312 if (ctx.mode == 0) {
313 printf("symlink %"PRIuMAX"\n%s\n",
314 (uintmax_t)ctx.symlink_path.len,
315 ctx.symlink_path.buf);
316 fflush(stdout);
317 return;
318 }
319
320 batch_object_write(obj_name, opt, data);
321 }
322
323 struct object_cb_data {
324 struct batch_options *opt;
325 struct expand_data *expand;
326 };
327
328 static void batch_object_cb(const unsigned char sha1[20], void *vdata)
329 {
330 struct object_cb_data *data = vdata;
331 hashcpy(data->expand->sha1, sha1);
332 batch_object_write(NULL, data->opt, data->expand);
333 }
334
335 static int batch_loose_object(const unsigned char *sha1,
336 const char *path,
337 void *data)
338 {
339 sha1_array_append(data, sha1);
340 return 0;
341 }
342
343 static int batch_packed_object(const unsigned char *sha1,
344 struct packed_git *pack,
345 uint32_t pos,
346 void *data)
347 {
348 sha1_array_append(data, sha1);
349 return 0;
350 }
351
352 static int batch_objects(struct batch_options *opt)
353 {
354 struct strbuf buf = STRBUF_INIT;
355 struct expand_data data;
356 int save_warning;
357 int retval = 0;
358
359 if (!opt->format)
360 opt->format = "%(objectname) %(objecttype) %(objectsize)";
361
362 /*
363 * Expand once with our special mark_query flag, which will prime the
364 * object_info to be handed to sha1_object_info_extended for each
365 * object.
366 */
367 memset(&data, 0, sizeof(data));
368 data.mark_query = 1;
369 strbuf_expand(&buf, opt->format, expand_format, &data);
370 data.mark_query = 0;
371
372 /*
373 * If we are printing out the object, then always fill in the type,
374 * since we will want to decide whether or not to stream.
375 */
376 if (opt->print_contents)
377 data.info.typep = &data.type;
378
379 if (opt->all_objects) {
380 struct sha1_array sa = SHA1_ARRAY_INIT;
381 struct object_cb_data cb;
382
383 for_each_loose_object(batch_loose_object, &sa, 0);
384 for_each_packed_object(batch_packed_object, &sa, 0);
385
386 cb.opt = opt;
387 cb.expand = &data;
388 sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
389
390 sha1_array_clear(&sa);
391 return 0;
392 }
393
394 /*
395 * We are going to call get_sha1 on a potentially very large number of
396 * objects. In most large cases, these will be actual object sha1s. The
397 * cost to double-check that each one is not also a ref (just so we can
398 * warn) ends up dwarfing the actual cost of the object lookups
399 * themselves. We can work around it by just turning off the warning.
400 */
401 save_warning = warn_on_object_refname_ambiguity;
402 warn_on_object_refname_ambiguity = 0;
403
404 while (strbuf_getline(&buf, stdin) != EOF) {
405 if (data.split_on_whitespace) {
406 /*
407 * Split at first whitespace, tying off the beginning
408 * of the string and saving the remainder (or NULL) in
409 * data.rest.
410 */
411 char *p = strpbrk(buf.buf, " \t");
412 if (p) {
413 while (*p && strchr(" \t", *p))
414 *p++ = '\0';
415 }
416 data.rest = p;
417 }
418
419 batch_one_object(buf.buf, opt, &data);
420 }
421
422 strbuf_release(&buf);
423 warn_on_object_refname_ambiguity = save_warning;
424 return retval;
425 }
426
427 static const char * const cat_file_usage[] = {
428 N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
429 N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
430 NULL
431 };
432
433 static int git_cat_file_config(const char *var, const char *value, void *cb)
434 {
435 if (userdiff_config(var, value) < 0)
436 return -1;
437
438 return git_default_config(var, value, cb);
439 }
440
441 static int batch_option_callback(const struct option *opt,
442 const char *arg,
443 int unset)
444 {
445 struct batch_options *bo = opt->value;
446
447 if (bo->enabled) {
448 return 1;
449 }
450
451 bo->enabled = 1;
452 bo->print_contents = !strcmp(opt->long_name, "batch");
453 bo->format = arg;
454
455 return 0;
456 }
457
458 int cmd_cat_file(int argc, const char **argv, const char *prefix)
459 {
460 int opt = 0;
461 const char *exp_type = NULL, *obj_name = NULL;
462 struct batch_options batch = {0};
463 int unknown_type = 0;
464
465 const struct option options[] = {
466 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
467 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
468 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
469 OPT_CMDMODE('e', NULL, &opt,
470 N_("exit with zero when there's no error"), 'e'),
471 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
472 OPT_CMDMODE(0, "textconv", &opt,
473 N_("for blob objects, run textconv on object's content"), 'c'),
474 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
475 N_("allow -s and -t to work with broken/corrupt objects")),
476 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
477 { OPTION_CALLBACK, 0, "batch", &batch, "format",
478 N_("show info and content of objects fed from the standard input"),
479 PARSE_OPT_OPTARG, batch_option_callback },
480 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
481 N_("show info about objects fed from the standard input"),
482 PARSE_OPT_OPTARG, batch_option_callback },
483 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
484 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
485 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
486 N_("show all objects with --batch or --batch-check")),
487 OPT_END()
488 };
489
490 git_config(git_cat_file_config, NULL);
491
492 argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
493
494 if (opt) {
495 if (argc == 1)
496 obj_name = argv[0];
497 else
498 usage_with_options(cat_file_usage, options);
499 }
500 if (!opt && !batch.enabled) {
501 if (argc == 2) {
502 exp_type = argv[0];
503 obj_name = argv[1];
504 } else
505 usage_with_options(cat_file_usage, options);
506 }
507 if (batch.enabled && (opt || argc)) {
508 usage_with_options(cat_file_usage, options);
509 }
510
511 if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
512 usage_with_options(cat_file_usage, options);
513 }
514
515 if (batch.enabled)
516 return batch_objects(&batch);
517
518 if (unknown_type && opt != 't' && opt != 's')
519 die("git cat-file --allow-unknown-type: use with -s or -t");
520 return cat_one_file(opt, exp_type, obj_name, unknown_type);
521 }