Merge branch 'km/branch-get-push-while-detached' into maint
[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         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
21         const char *format;
22 };
23
24 static const char *force_path;
25
26 static int filter_object(const char *path, unsigned mode,
27                          const struct object_id *oid,
28                          char **buf, unsigned long *size)
29 {
30         enum object_type type;
31
32         *buf = read_sha1_file(oid->hash, &type, size);
33         if (!*buf)
34                 return error(_("cannot read object %s '%s'"),
35                              oid_to_hex(oid), path);
36         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
37                 struct strbuf strbuf = STRBUF_INIT;
38                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
39                         free(*buf);
40                         *size = strbuf.len;
41                         *buf = strbuf_detach(&strbuf, NULL);
42                 }
43         }
44
45         return 0;
46 }
47
48 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
49                         int unknown_type)
50 {
51         struct object_id oid;
52         enum object_type type;
53         char *buf;
54         unsigned long size;
55         struct object_context obj_context;
56         struct object_info oi = OBJECT_INFO_INIT;
57         struct strbuf sb = STRBUF_INIT;
58         unsigned flags = LOOKUP_REPLACE_OBJECT;
59         const char *path = force_path;
60
61         if (unknown_type)
62                 flags |= LOOKUP_UNKNOWN_OBJECT;
63
64         if (get_sha1_with_context(obj_name, 0, oid.hash, &obj_context))
65                 die("Not a valid object name %s", obj_name);
66
67         if (!path)
68                 path = obj_context.path;
69         if (obj_context.mode == S_IFINVALID)
70                 obj_context.mode = 0100644;
71
72         buf = NULL;
73         switch (opt) {
74         case 't':
75                 oi.typename = &sb;
76                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
77                         die("git cat-file: could not get object info");
78                 if (sb.len) {
79                         printf("%s\n", sb.buf);
80                         strbuf_release(&sb);
81                         return 0;
82                 }
83                 break;
84
85         case 's':
86                 oi.sizep = &size;
87                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
88                         die("git cat-file: could not get object info");
89                 printf("%lu\n", size);
90                 return 0;
91
92         case 'e':
93                 return !has_object_file(&oid);
94
95         case 'w':
96                 if (!path[0])
97                         die("git cat-file --filters %s: <object> must be "
98                             "<sha1:path>", obj_name);
99
100                 if (filter_object(path, obj_context.mode,
101                                   &oid, &buf, &size))
102                         return -1;
103                 break;
104
105         case 'c':
106                 if (!path[0])
107                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
108                             obj_name);
109
110                 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
111                         break;
112
113         case 'p':
114                 type = sha1_object_info(oid.hash, NULL);
115                 if (type < 0)
116                         die("Not a valid object name %s", obj_name);
117
118                 /* custom pretty-print here */
119                 if (type == OBJ_TREE) {
120                         const char *ls_args[3] = { NULL };
121                         ls_args[0] =  "ls-tree";
122                         ls_args[1] =  obj_name;
123                         return cmd_ls_tree(2, ls_args, NULL);
124                 }
125
126                 if (type == OBJ_BLOB)
127                         return stream_blob_to_fd(1, &oid, NULL, 0);
128                 buf = read_sha1_file(oid.hash, &type, &size);
129                 if (!buf)
130                         die("Cannot read object %s", obj_name);
131
132                 /* otherwise just spit out the data */
133                 break;
134
135         case 0:
136                 if (type_from_string(exp_type) == OBJ_BLOB) {
137                         struct object_id blob_oid;
138                         if (sha1_object_info(oid.hash, NULL) == OBJ_TAG) {
139                                 char *buffer = read_sha1_file(oid.hash, &type, &size);
140                                 const char *target;
141                                 if (!skip_prefix(buffer, "object ", &target) ||
142                                     get_oid_hex(target, &blob_oid))
143                                         die("%s not a valid tag", oid_to_hex(&oid));
144                                 free(buffer);
145                         } else
146                                 oidcpy(&blob_oid, &oid);
147
148                         if (sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
149                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
150                         /*
151                          * we attempted to dereference a tag to a blob
152                          * and failed; there may be new dereference
153                          * mechanisms this code is not aware of.
154                          * fall-back to the usual case.
155                          */
156                 }
157                 buf = read_object_with_reference(oid.hash, exp_type, &size, NULL);
158                 break;
159
160         default:
161                 die("git cat-file: unknown option: %s", exp_type);
162         }
163
164         if (!buf)
165                 die("git cat-file %s: bad file", obj_name);
166
167         write_or_die(1, buf, size);
168         return 0;
169 }
170
171 struct expand_data {
172         struct object_id oid;
173         enum object_type type;
174         unsigned long size;
175         off_t disk_size;
176         const char *rest;
177         struct object_id delta_base_oid;
178
179         /*
180          * If mark_query is true, we do not expand anything, but rather
181          * just mark the object_info with items we wish to query.
182          */
183         int mark_query;
184
185         /*
186          * Whether to split the input on whitespace before feeding it to
187          * get_sha1; this is decided during the mark_query phase based on
188          * whether we have a %(rest) token in our format.
189          */
190         int split_on_whitespace;
191
192         /*
193          * After a mark_query run, this object_info is set up to be
194          * passed to sha1_object_info_extended. It will point to the data
195          * elements above, so you can retrieve the response from there.
196          */
197         struct object_info info;
198
199         /*
200          * This flag will be true if the requested batch format and options
201          * don't require us to call sha1_object_info, which can then be
202          * optimized out.
203          */
204         unsigned skip_object_info : 1;
205 };
206
207 static int is_atom(const char *atom, const char *s, int slen)
208 {
209         int alen = strlen(atom);
210         return alen == slen && !memcmp(atom, s, alen);
211 }
212
213 static void expand_atom(struct strbuf *sb, const char *atom, int len,
214                         void *vdata)
215 {
216         struct expand_data *data = vdata;
217
218         if (is_atom("objectname", atom, len)) {
219                 if (!data->mark_query)
220                         strbuf_addstr(sb, oid_to_hex(&data->oid));
221         } else if (is_atom("objecttype", atom, len)) {
222                 if (data->mark_query)
223                         data->info.typep = &data->type;
224                 else
225                         strbuf_addstr(sb, typename(data->type));
226         } else if (is_atom("objectsize", atom, len)) {
227                 if (data->mark_query)
228                         data->info.sizep = &data->size;
229                 else
230                         strbuf_addf(sb, "%lu", data->size);
231         } else if (is_atom("objectsize:disk", atom, len)) {
232                 if (data->mark_query)
233                         data->info.disk_sizep = &data->disk_size;
234                 else
235                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
236         } else if (is_atom("rest", atom, len)) {
237                 if (data->mark_query)
238                         data->split_on_whitespace = 1;
239                 else if (data->rest)
240                         strbuf_addstr(sb, data->rest);
241         } else if (is_atom("deltabase", atom, len)) {
242                 if (data->mark_query)
243                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
244                 else
245                         strbuf_addstr(sb,
246                                       oid_to_hex(&data->delta_base_oid));
247         } else
248                 die("unknown format element: %.*s", len, atom);
249 }
250
251 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
252 {
253         const char *end;
254
255         if (*start != '(')
256                 return 0;
257         end = strchr(start + 1, ')');
258         if (!end)
259                 die("format element '%s' does not end in ')'", start);
260
261         expand_atom(sb, start + 1, end - start - 1, data);
262
263         return end - start + 1;
264 }
265
266 static void batch_write(struct batch_options *opt, const void *data, int len)
267 {
268         if (opt->buffer_output) {
269                 if (fwrite(data, 1, len, stdout) != len)
270                         die_errno("unable to write to stdout");
271         } else
272                 write_or_die(1, data, len);
273 }
274
275 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
276 {
277         const struct object_id *oid = &data->oid;
278
279         assert(data->info.typep);
280
281         if (data->type == OBJ_BLOB) {
282                 if (opt->buffer_output)
283                         fflush(stdout);
284                 if (opt->cmdmode) {
285                         char *contents;
286                         unsigned long size;
287
288                         if (!data->rest)
289                                 die("missing path for '%s'", oid_to_hex(oid));
290
291                         if (opt->cmdmode == 'w') {
292                                 if (filter_object(data->rest, 0100644, oid,
293                                                   &contents, &size))
294                                         die("could not convert '%s' %s",
295                                             oid_to_hex(oid), data->rest);
296                         } else if (opt->cmdmode == 'c') {
297                                 enum object_type type;
298                                 if (!textconv_object(data->rest, 0100644, oid,
299                                                      1, &contents, &size))
300                                         contents = read_sha1_file(oid->hash, &type,
301                                                                   &size);
302                                 if (!contents)
303                                         die("could not convert '%s' %s",
304                                             oid_to_hex(oid), data->rest);
305                         } else
306                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
307                         batch_write(opt, contents, size);
308                         free(contents);
309                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
310                         die("unable to stream %s to stdout", oid_to_hex(oid));
311         }
312         else {
313                 enum object_type type;
314                 unsigned long size;
315                 void *contents;
316
317                 contents = read_sha1_file(oid->hash, &type, &size);
318                 if (!contents)
319                         die("object %s disappeared", oid_to_hex(oid));
320                 if (type != data->type)
321                         die("object %s changed type!?", oid_to_hex(oid));
322                 if (data->info.sizep && size != data->size)
323                         die("object %s changed size!?", oid_to_hex(oid));
324
325                 batch_write(opt, contents, size);
326                 free(contents);
327         }
328 }
329
330 static void batch_object_write(const char *obj_name, struct batch_options *opt,
331                                struct expand_data *data)
332 {
333         struct strbuf buf = STRBUF_INIT;
334
335         if (!data->skip_object_info &&
336             sha1_object_info_extended(data->oid.hash, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
337                 printf("%s missing\n",
338                        obj_name ? obj_name : oid_to_hex(&data->oid));
339                 fflush(stdout);
340                 return;
341         }
342
343         strbuf_expand(&buf, opt->format, expand_format, data);
344         strbuf_addch(&buf, '\n');
345         batch_write(opt, buf.buf, buf.len);
346         strbuf_release(&buf);
347
348         if (opt->print_contents) {
349                 print_object_or_die(opt, data);
350                 batch_write(opt, "\n", 1);
351         }
352 }
353
354 static void batch_one_object(const char *obj_name, struct batch_options *opt,
355                              struct expand_data *data)
356 {
357         struct object_context ctx;
358         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
359         enum follow_symlinks_result result;
360
361         result = get_sha1_with_context(obj_name, flags, data->oid.hash, &ctx);
362         if (result != FOUND) {
363                 switch (result) {
364                 case MISSING_OBJECT:
365                         printf("%s missing\n", obj_name);
366                         break;
367                 case DANGLING_SYMLINK:
368                         printf("dangling %"PRIuMAX"\n%s\n",
369                                (uintmax_t)strlen(obj_name), obj_name);
370                         break;
371                 case SYMLINK_LOOP:
372                         printf("loop %"PRIuMAX"\n%s\n",
373                                (uintmax_t)strlen(obj_name), obj_name);
374                         break;
375                 case NOT_DIR:
376                         printf("notdir %"PRIuMAX"\n%s\n",
377                                (uintmax_t)strlen(obj_name), obj_name);
378                         break;
379                 default:
380                         die("BUG: unknown get_sha1_with_context result %d\n",
381                                result);
382                         break;
383                 }
384                 fflush(stdout);
385                 return;
386         }
387
388         if (ctx.mode == 0) {
389                 printf("symlink %"PRIuMAX"\n%s\n",
390                        (uintmax_t)ctx.symlink_path.len,
391                        ctx.symlink_path.buf);
392                 fflush(stdout);
393                 return;
394         }
395
396         batch_object_write(obj_name, opt, data);
397 }
398
399 struct object_cb_data {
400         struct batch_options *opt;
401         struct expand_data *expand;
402 };
403
404 static int batch_object_cb(const unsigned char sha1[20], void *vdata)
405 {
406         struct object_cb_data *data = vdata;
407         hashcpy(data->expand->oid.hash, sha1);
408         batch_object_write(NULL, data->opt, data->expand);
409         return 0;
410 }
411
412 static int batch_loose_object(const unsigned char *sha1,
413                               const char *path,
414                               void *data)
415 {
416         sha1_array_append(data, sha1);
417         return 0;
418 }
419
420 static int batch_packed_object(const unsigned char *sha1,
421                                struct packed_git *pack,
422                                uint32_t pos,
423                                void *data)
424 {
425         sha1_array_append(data, sha1);
426         return 0;
427 }
428
429 static int batch_objects(struct batch_options *opt)
430 {
431         struct strbuf buf = STRBUF_INIT;
432         struct expand_data data;
433         int save_warning;
434         int retval = 0;
435
436         if (!opt->format)
437                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
438
439         /*
440          * Expand once with our special mark_query flag, which will prime the
441          * object_info to be handed to sha1_object_info_extended for each
442          * object.
443          */
444         memset(&data, 0, sizeof(data));
445         data.mark_query = 1;
446         strbuf_expand(&buf, opt->format, expand_format, &data);
447         data.mark_query = 0;
448         if (opt->cmdmode)
449                 data.split_on_whitespace = 1;
450
451         if (opt->all_objects) {
452                 struct object_info empty = OBJECT_INFO_INIT;
453                 if (!memcmp(&data.info, &empty, sizeof(empty)))
454                         data.skip_object_info = 1;
455         }
456
457         /*
458          * If we are printing out the object, then always fill in the type,
459          * since we will want to decide whether or not to stream.
460          */
461         if (opt->print_contents)
462                 data.info.typep = &data.type;
463
464         if (opt->all_objects) {
465                 struct sha1_array sa = SHA1_ARRAY_INIT;
466                 struct object_cb_data cb;
467
468                 for_each_loose_object(batch_loose_object, &sa, 0);
469                 for_each_packed_object(batch_packed_object, &sa, 0);
470
471                 cb.opt = opt;
472                 cb.expand = &data;
473                 sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
474
475                 sha1_array_clear(&sa);
476                 return 0;
477         }
478
479         /*
480          * We are going to call get_sha1 on a potentially very large number of
481          * objects. In most large cases, these will be actual object sha1s. The
482          * cost to double-check that each one is not also a ref (just so we can
483          * warn) ends up dwarfing the actual cost of the object lookups
484          * themselves. We can work around it by just turning off the warning.
485          */
486         save_warning = warn_on_object_refname_ambiguity;
487         warn_on_object_refname_ambiguity = 0;
488
489         while (strbuf_getline(&buf, stdin) != EOF) {
490                 if (data.split_on_whitespace) {
491                         /*
492                          * Split at first whitespace, tying off the beginning
493                          * of the string and saving the remainder (or NULL) in
494                          * data.rest.
495                          */
496                         char *p = strpbrk(buf.buf, " \t");
497                         if (p) {
498                                 while (*p && strchr(" \t", *p))
499                                         *p++ = '\0';
500                         }
501                         data.rest = p;
502                 }
503
504                 batch_one_object(buf.buf, opt, &data);
505         }
506
507         strbuf_release(&buf);
508         warn_on_object_refname_ambiguity = save_warning;
509         return retval;
510 }
511
512 static const char * const cat_file_usage[] = {
513         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
514         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
515         NULL
516 };
517
518 static int git_cat_file_config(const char *var, const char *value, void *cb)
519 {
520         if (userdiff_config(var, value) < 0)
521                 return -1;
522
523         return git_default_config(var, value, cb);
524 }
525
526 static int batch_option_callback(const struct option *opt,
527                                  const char *arg,
528                                  int unset)
529 {
530         struct batch_options *bo = opt->value;
531
532         if (bo->enabled) {
533                 return 1;
534         }
535
536         bo->enabled = 1;
537         bo->print_contents = !strcmp(opt->long_name, "batch");
538         bo->format = arg;
539
540         return 0;
541 }
542
543 int cmd_cat_file(int argc, const char **argv, const char *prefix)
544 {
545         int opt = 0;
546         const char *exp_type = NULL, *obj_name = NULL;
547         struct batch_options batch = {0};
548         int unknown_type = 0;
549
550         const struct option options[] = {
551                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
552                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
553                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
554                 OPT_CMDMODE('e', NULL, &opt,
555                             N_("exit with zero when there's no error"), 'e'),
556                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
557                 OPT_CMDMODE(0, "textconv", &opt,
558                             N_("for blob objects, run textconv on object's content"), 'c'),
559                 OPT_CMDMODE(0, "filters", &opt,
560                             N_("for blob objects, run filters on object's content"), 'w'),
561                 OPT_STRING(0, "path", &force_path, N_("blob"),
562                            N_("use a specific path for --textconv/--filters")),
563                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
564                           N_("allow -s and -t to work with broken/corrupt objects")),
565                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
566                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
567                         N_("show info and content of objects fed from the standard input"),
568                         PARSE_OPT_OPTARG, batch_option_callback },
569                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
570                         N_("show info about objects fed from the standard input"),
571                         PARSE_OPT_OPTARG, batch_option_callback },
572                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
573                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
574                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
575                          N_("show all objects with --batch or --batch-check")),
576                 OPT_END()
577         };
578
579         git_config(git_cat_file_config, NULL);
580
581         batch.buffer_output = -1;
582         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
583
584         if (opt) {
585                 if (batch.enabled && (opt == 'c' || opt == 'w'))
586                         batch.cmdmode = opt;
587                 else if (argc == 1)
588                         obj_name = argv[0];
589                 else
590                         usage_with_options(cat_file_usage, options);
591         }
592         if (!opt && !batch.enabled) {
593                 if (argc == 2) {
594                         exp_type = argv[0];
595                         obj_name = argv[1];
596                 } else
597                         usage_with_options(cat_file_usage, options);
598         }
599         if (batch.enabled) {
600                 if (batch.cmdmode != opt || argc)
601                         usage_with_options(cat_file_usage, options);
602                 if (batch.cmdmode && batch.all_objects)
603                         die("--batch-all-objects cannot be combined with "
604                             "--textconv nor with --filters");
605         }
606
607         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
608                 usage_with_options(cat_file_usage, options);
609         }
610
611         if (force_path && opt != 'c' && opt != 'w') {
612                 error("--path=<path> needs --textconv or --filters");
613                 usage_with_options(cat_file_usage, options);
614         }
615
616         if (force_path && batch.enabled) {
617                 error("--path=<path> incompatible with --batch");
618                 usage_with_options(cat_file_usage, options);
619         }
620
621         if (batch.buffer_output < 0)
622                 batch.buffer_output = batch.all_objects;
623
624         if (batch.enabled)
625                 return batch_objects(&batch);
626
627         if (unknown_type && opt != 't' && opt != 's')
628                 die("git cat-file --allow-unknown-type: use with -s or -t");
629         return cat_one_file(opt, exp_type, obj_name, unknown_type);
630 }