Merge branch 'js/bs-is-a-dir-sep-on-windows'
[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         free(buf);
169         return 0;
170 }
171
172 struct expand_data {
173         struct object_id oid;
174         enum object_type type;
175         unsigned long size;
176         off_t disk_size;
177         const char *rest;
178         struct object_id delta_base_oid;
179
180         /*
181          * If mark_query is true, we do not expand anything, but rather
182          * just mark the object_info with items we wish to query.
183          */
184         int mark_query;
185
186         /*
187          * Whether to split the input on whitespace before feeding it to
188          * get_sha1; this is decided during the mark_query phase based on
189          * whether we have a %(rest) token in our format.
190          */
191         int split_on_whitespace;
192
193         /*
194          * After a mark_query run, this object_info is set up to be
195          * passed to sha1_object_info_extended. It will point to the data
196          * elements above, so you can retrieve the response from there.
197          */
198         struct object_info info;
199
200         /*
201          * This flag will be true if the requested batch format and options
202          * don't require us to call sha1_object_info, which can then be
203          * optimized out.
204          */
205         unsigned skip_object_info : 1;
206 };
207
208 static int is_atom(const char *atom, const char *s, int slen)
209 {
210         int alen = strlen(atom);
211         return alen == slen && !memcmp(atom, s, alen);
212 }
213
214 static void expand_atom(struct strbuf *sb, const char *atom, int len,
215                         void *vdata)
216 {
217         struct expand_data *data = vdata;
218
219         if (is_atom("objectname", atom, len)) {
220                 if (!data->mark_query)
221                         strbuf_addstr(sb, oid_to_hex(&data->oid));
222         } else if (is_atom("objecttype", atom, len)) {
223                 if (data->mark_query)
224                         data->info.typep = &data->type;
225                 else
226                         strbuf_addstr(sb, typename(data->type));
227         } else if (is_atom("objectsize", atom, len)) {
228                 if (data->mark_query)
229                         data->info.sizep = &data->size;
230                 else
231                         strbuf_addf(sb, "%lu", data->size);
232         } else if (is_atom("objectsize:disk", atom, len)) {
233                 if (data->mark_query)
234                         data->info.disk_sizep = &data->disk_size;
235                 else
236                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
237         } else if (is_atom("rest", atom, len)) {
238                 if (data->mark_query)
239                         data->split_on_whitespace = 1;
240                 else if (data->rest)
241                         strbuf_addstr(sb, data->rest);
242         } else if (is_atom("deltabase", atom, len)) {
243                 if (data->mark_query)
244                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
245                 else
246                         strbuf_addstr(sb,
247                                       oid_to_hex(&data->delta_base_oid));
248         } else
249                 die("unknown format element: %.*s", len, atom);
250 }
251
252 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
253 {
254         const char *end;
255
256         if (*start != '(')
257                 return 0;
258         end = strchr(start + 1, ')');
259         if (!end)
260                 die("format element '%s' does not end in ')'", start);
261
262         expand_atom(sb, start + 1, end - start - 1, data);
263
264         return end - start + 1;
265 }
266
267 static void batch_write(struct batch_options *opt, const void *data, int len)
268 {
269         if (opt->buffer_output) {
270                 if (fwrite(data, 1, len, stdout) != len)
271                         die_errno("unable to write to stdout");
272         } else
273                 write_or_die(1, data, len);
274 }
275
276 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
277 {
278         const struct object_id *oid = &data->oid;
279
280         assert(data->info.typep);
281
282         if (data->type == OBJ_BLOB) {
283                 if (opt->buffer_output)
284                         fflush(stdout);
285                 if (opt->cmdmode) {
286                         char *contents;
287                         unsigned long size;
288
289                         if (!data->rest)
290                                 die("missing path for '%s'", oid_to_hex(oid));
291
292                         if (opt->cmdmode == 'w') {
293                                 if (filter_object(data->rest, 0100644, oid,
294                                                   &contents, &size))
295                                         die("could not convert '%s' %s",
296                                             oid_to_hex(oid), data->rest);
297                         } else if (opt->cmdmode == 'c') {
298                                 enum object_type type;
299                                 if (!textconv_object(data->rest, 0100644, oid,
300                                                      1, &contents, &size))
301                                         contents = read_sha1_file(oid->hash, &type,
302                                                                   &size);
303                                 if (!contents)
304                                         die("could not convert '%s' %s",
305                                             oid_to_hex(oid), data->rest);
306                         } else
307                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
308                         batch_write(opt, contents, size);
309                         free(contents);
310                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
311                         die("unable to stream %s to stdout", oid_to_hex(oid));
312         }
313         else {
314                 enum object_type type;
315                 unsigned long size;
316                 void *contents;
317
318                 contents = read_sha1_file(oid->hash, &type, &size);
319                 if (!contents)
320                         die("object %s disappeared", oid_to_hex(oid));
321                 if (type != data->type)
322                         die("object %s changed type!?", oid_to_hex(oid));
323                 if (data->info.sizep && size != data->size)
324                         die("object %s changed size!?", oid_to_hex(oid));
325
326                 batch_write(opt, contents, size);
327                 free(contents);
328         }
329 }
330
331 static void batch_object_write(const char *obj_name, struct batch_options *opt,
332                                struct expand_data *data)
333 {
334         struct strbuf buf = STRBUF_INIT;
335
336         if (!data->skip_object_info &&
337             sha1_object_info_extended(data->oid.hash, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
338                 printf("%s missing\n",
339                        obj_name ? obj_name : oid_to_hex(&data->oid));
340                 fflush(stdout);
341                 return;
342         }
343
344         strbuf_expand(&buf, opt->format, expand_format, data);
345         strbuf_addch(&buf, '\n');
346         batch_write(opt, buf.buf, buf.len);
347         strbuf_release(&buf);
348
349         if (opt->print_contents) {
350                 print_object_or_die(opt, data);
351                 batch_write(opt, "\n", 1);
352         }
353 }
354
355 static void batch_one_object(const char *obj_name, struct batch_options *opt,
356                              struct expand_data *data)
357 {
358         struct object_context ctx;
359         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
360         enum follow_symlinks_result result;
361
362         result = get_sha1_with_context(obj_name, flags, data->oid.hash, &ctx);
363         if (result != FOUND) {
364                 switch (result) {
365                 case MISSING_OBJECT:
366                         printf("%s missing\n", obj_name);
367                         break;
368                 case DANGLING_SYMLINK:
369                         printf("dangling %"PRIuMAX"\n%s\n",
370                                (uintmax_t)strlen(obj_name), obj_name);
371                         break;
372                 case SYMLINK_LOOP:
373                         printf("loop %"PRIuMAX"\n%s\n",
374                                (uintmax_t)strlen(obj_name), obj_name);
375                         break;
376                 case NOT_DIR:
377                         printf("notdir %"PRIuMAX"\n%s\n",
378                                (uintmax_t)strlen(obj_name), obj_name);
379                         break;
380                 default:
381                         die("BUG: unknown get_sha1_with_context result %d\n",
382                                result);
383                         break;
384                 }
385                 fflush(stdout);
386                 return;
387         }
388
389         if (ctx.mode == 0) {
390                 printf("symlink %"PRIuMAX"\n%s\n",
391                        (uintmax_t)ctx.symlink_path.len,
392                        ctx.symlink_path.buf);
393                 fflush(stdout);
394                 return;
395         }
396
397         batch_object_write(obj_name, opt, data);
398 }
399
400 struct object_cb_data {
401         struct batch_options *opt;
402         struct expand_data *expand;
403 };
404
405 static int batch_object_cb(const struct object_id *oid, void *vdata)
406 {
407         struct object_cb_data *data = vdata;
408         oidcpy(&data->expand->oid, oid);
409         batch_object_write(NULL, data->opt, data->expand);
410         return 0;
411 }
412
413 static int batch_loose_object(const struct object_id *oid,
414                               const char *path,
415                               void *data)
416 {
417         oid_array_append(data, oid);
418         return 0;
419 }
420
421 static int batch_packed_object(const struct object_id *oid,
422                                struct packed_git *pack,
423                                uint32_t pos,
424                                void *data)
425 {
426         oid_array_append(data, oid);
427         return 0;
428 }
429
430 static int batch_objects(struct batch_options *opt)
431 {
432         struct strbuf buf = STRBUF_INIT;
433         struct expand_data data;
434         int save_warning;
435         int retval = 0;
436
437         if (!opt->format)
438                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
439
440         /*
441          * Expand once with our special mark_query flag, which will prime the
442          * object_info to be handed to sha1_object_info_extended for each
443          * object.
444          */
445         memset(&data, 0, sizeof(data));
446         data.mark_query = 1;
447         strbuf_expand(&buf, opt->format, expand_format, &data);
448         data.mark_query = 0;
449         if (opt->cmdmode)
450                 data.split_on_whitespace = 1;
451
452         if (opt->all_objects) {
453                 struct object_info empty = OBJECT_INFO_INIT;
454                 if (!memcmp(&data.info, &empty, sizeof(empty)))
455                         data.skip_object_info = 1;
456         }
457
458         /*
459          * If we are printing out the object, then always fill in the type,
460          * since we will want to decide whether or not to stream.
461          */
462         if (opt->print_contents)
463                 data.info.typep = &data.type;
464
465         if (opt->all_objects) {
466                 struct oid_array sa = OID_ARRAY_INIT;
467                 struct object_cb_data cb;
468
469                 for_each_loose_object(batch_loose_object, &sa, 0);
470                 for_each_packed_object(batch_packed_object, &sa, 0);
471
472                 cb.opt = opt;
473                 cb.expand = &data;
474                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
475
476                 oid_array_clear(&sa);
477                 return 0;
478         }
479
480         /*
481          * We are going to call get_sha1 on a potentially very large number of
482          * objects. In most large cases, these will be actual object sha1s. The
483          * cost to double-check that each one is not also a ref (just so we can
484          * warn) ends up dwarfing the actual cost of the object lookups
485          * themselves. We can work around it by just turning off the warning.
486          */
487         save_warning = warn_on_object_refname_ambiguity;
488         warn_on_object_refname_ambiguity = 0;
489
490         while (strbuf_getline(&buf, stdin) != EOF) {
491                 if (data.split_on_whitespace) {
492                         /*
493                          * Split at first whitespace, tying off the beginning
494                          * of the string and saving the remainder (or NULL) in
495                          * data.rest.
496                          */
497                         char *p = strpbrk(buf.buf, " \t");
498                         if (p) {
499                                 while (*p && strchr(" \t", *p))
500                                         *p++ = '\0';
501                         }
502                         data.rest = p;
503                 }
504
505                 batch_one_object(buf.buf, opt, &data);
506         }
507
508         strbuf_release(&buf);
509         warn_on_object_refname_ambiguity = save_warning;
510         return retval;
511 }
512
513 static const char * const cat_file_usage[] = {
514         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
515         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
516         NULL
517 };
518
519 static int git_cat_file_config(const char *var, const char *value, void *cb)
520 {
521         if (userdiff_config(var, value) < 0)
522                 return -1;
523
524         return git_default_config(var, value, cb);
525 }
526
527 static int batch_option_callback(const struct option *opt,
528                                  const char *arg,
529                                  int unset)
530 {
531         struct batch_options *bo = opt->value;
532
533         if (bo->enabled) {
534                 return 1;
535         }
536
537         bo->enabled = 1;
538         bo->print_contents = !strcmp(opt->long_name, "batch");
539         bo->format = arg;
540
541         return 0;
542 }
543
544 int cmd_cat_file(int argc, const char **argv, const char *prefix)
545 {
546         int opt = 0;
547         const char *exp_type = NULL, *obj_name = NULL;
548         struct batch_options batch = {0};
549         int unknown_type = 0;
550
551         const struct option options[] = {
552                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
553                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
554                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
555                 OPT_CMDMODE('e', NULL, &opt,
556                             N_("exit with zero when there's no error"), 'e'),
557                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
558                 OPT_CMDMODE(0, "textconv", &opt,
559                             N_("for blob objects, run textconv on object's content"), 'c'),
560                 OPT_CMDMODE(0, "filters", &opt,
561                             N_("for blob objects, run filters on object's content"), 'w'),
562                 OPT_STRING(0, "path", &force_path, N_("blob"),
563                            N_("use a specific path for --textconv/--filters")),
564                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
565                           N_("allow -s and -t to work with broken/corrupt objects")),
566                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
567                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
568                         N_("show info and content of objects fed from the standard input"),
569                         PARSE_OPT_OPTARG, batch_option_callback },
570                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
571                         N_("show info about objects fed from the standard input"),
572                         PARSE_OPT_OPTARG, batch_option_callback },
573                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
574                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
575                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
576                          N_("show all objects with --batch or --batch-check")),
577                 OPT_END()
578         };
579
580         git_config(git_cat_file_config, NULL);
581
582         batch.buffer_output = -1;
583         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
584
585         if (opt) {
586                 if (batch.enabled && (opt == 'c' || opt == 'w'))
587                         batch.cmdmode = opt;
588                 else if (argc == 1)
589                         obj_name = argv[0];
590                 else
591                         usage_with_options(cat_file_usage, options);
592         }
593         if (!opt && !batch.enabled) {
594                 if (argc == 2) {
595                         exp_type = argv[0];
596                         obj_name = argv[1];
597                 } else
598                         usage_with_options(cat_file_usage, options);
599         }
600         if (batch.enabled) {
601                 if (batch.cmdmode != opt || argc)
602                         usage_with_options(cat_file_usage, options);
603                 if (batch.cmdmode && batch.all_objects)
604                         die("--batch-all-objects cannot be combined with "
605                             "--textconv nor with --filters");
606         }
607
608         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
609                 usage_with_options(cat_file_usage, options);
610         }
611
612         if (force_path && opt != 'c' && opt != 'w') {
613                 error("--path=<path> needs --textconv or --filters");
614                 usage_with_options(cat_file_usage, options);
615         }
616
617         if (force_path && batch.enabled) {
618                 error("--path=<path> incompatible with --batch");
619                 usage_with_options(cat_file_usage, options);
620         }
621
622         if (batch.buffer_output < 0)
623                 batch.buffer_output = batch.all_objects;
624
625         if (batch.enabled)
626                 return batch_objects(&batch);
627
628         if (unknown_type && opt != 't' && opt != 's')
629                 die("git cat-file --allow-unknown-type: use with -s or -t");
630         return cat_one_file(opt, exp_type, obj_name, unknown_type);
631 }