Merge branch 'sb/t4005-modernize'
[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 "diff.h"
9 #include "parse-options.h"
10 #include "userdiff.h"
11 #include "streaming.h"
12 #include "tree-walk.h"
13 #include "sha1-array.h"
14
15 struct batch_options {
16         int enabled;
17         int follow_symlinks;
18         int print_contents;
19         int buffer_output;
20         int all_objects;
21         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
22         const char *format;
23 };
24
25 static const char *force_path;
26
27 static int filter_object(const char *path, unsigned mode,
28                          const struct object_id *oid,
29                          char **buf, unsigned long *size)
30 {
31         enum object_type type;
32
33         *buf = read_sha1_file(oid->hash, &type, size);
34         if (!*buf)
35                 return error(_("cannot read object %s '%s'"),
36                              oid_to_hex(oid), path);
37         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
38                 struct strbuf strbuf = STRBUF_INIT;
39                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
40                         free(*buf);
41                         *size = strbuf.len;
42                         *buf = strbuf_detach(&strbuf, NULL);
43                 }
44         }
45
46         return 0;
47 }
48
49 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
50                         int unknown_type)
51 {
52         struct object_id oid;
53         enum object_type type;
54         char *buf;
55         unsigned long size;
56         struct object_context obj_context;
57         struct object_info oi = OBJECT_INFO_INIT;
58         struct strbuf sb = STRBUF_INIT;
59         unsigned flags = LOOKUP_REPLACE_OBJECT;
60         const char *path = force_path;
61
62         if (unknown_type)
63                 flags |= LOOKUP_UNKNOWN_OBJECT;
64
65         if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH,
66                                   oid.hash, &obj_context))
67                 die("Not a valid object name %s", obj_name);
68
69         if (!path)
70                 path = obj_context.path;
71         if (obj_context.mode == S_IFINVALID)
72                 obj_context.mode = 0100644;
73
74         buf = NULL;
75         switch (opt) {
76         case 't':
77                 oi.typename = &sb;
78                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
79                         die("git cat-file: could not get object info");
80                 if (sb.len) {
81                         printf("%s\n", sb.buf);
82                         strbuf_release(&sb);
83                         return 0;
84                 }
85                 break;
86
87         case 's':
88                 oi.sizep = &size;
89                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
90                         die("git cat-file: could not get object info");
91                 printf("%lu\n", size);
92                 return 0;
93
94         case 'e':
95                 return !has_object_file(&oid);
96
97         case 'w':
98                 if (!path[0])
99                         die("git cat-file --filters %s: <object> must be "
100                             "<sha1:path>", obj_name);
101
102                 if (filter_object(path, obj_context.mode,
103                                   &oid, &buf, &size))
104                         return -1;
105                 break;
106
107         case 'c':
108                 if (!path[0])
109                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
110                             obj_name);
111
112                 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
113                         break;
114
115         case 'p':
116                 type = sha1_object_info(oid.hash, NULL);
117                 if (type < 0)
118                         die("Not a valid object name %s", obj_name);
119
120                 /* custom pretty-print here */
121                 if (type == OBJ_TREE) {
122                         const char *ls_args[3] = { NULL };
123                         ls_args[0] =  "ls-tree";
124                         ls_args[1] =  obj_name;
125                         return cmd_ls_tree(2, ls_args, NULL);
126                 }
127
128                 if (type == OBJ_BLOB)
129                         return stream_blob_to_fd(1, &oid, NULL, 0);
130                 buf = read_sha1_file(oid.hash, &type, &size);
131                 if (!buf)
132                         die("Cannot read object %s", obj_name);
133
134                 /* otherwise just spit out the data */
135                 break;
136
137         case 0:
138                 if (type_from_string(exp_type) == OBJ_BLOB) {
139                         struct object_id blob_oid;
140                         if (sha1_object_info(oid.hash, NULL) == OBJ_TAG) {
141                                 char *buffer = read_sha1_file(oid.hash, &type, &size);
142                                 const char *target;
143                                 if (!skip_prefix(buffer, "object ", &target) ||
144                                     get_oid_hex(target, &blob_oid))
145                                         die("%s not a valid tag", oid_to_hex(&oid));
146                                 free(buffer);
147                         } else
148                                 oidcpy(&blob_oid, &oid);
149
150                         if (sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
151                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
152                         /*
153                          * we attempted to dereference a tag to a blob
154                          * and failed; there may be new dereference
155                          * mechanisms this code is not aware of.
156                          * fall-back to the usual case.
157                          */
158                 }
159                 buf = read_object_with_reference(oid.hash, exp_type, &size, NULL);
160                 break;
161
162         default:
163                 die("git cat-file: unknown option: %s", exp_type);
164         }
165
166         if (!buf)
167                 die("git cat-file %s: bad file", obj_name);
168
169         write_or_die(1, buf, size);
170         free(buf);
171         free(obj_context.path);
172         return 0;
173 }
174
175 struct expand_data {
176         struct object_id oid;
177         enum object_type type;
178         unsigned long size;
179         off_t disk_size;
180         const char *rest;
181         struct object_id delta_base_oid;
182
183         /*
184          * If mark_query is true, we do not expand anything, but rather
185          * just mark the object_info with items we wish to query.
186          */
187         int mark_query;
188
189         /*
190          * Whether to split the input on whitespace before feeding it to
191          * get_sha1; this is decided during the mark_query phase based on
192          * whether we have a %(rest) token in our format.
193          */
194         int split_on_whitespace;
195
196         /*
197          * After a mark_query run, this object_info is set up to be
198          * passed to sha1_object_info_extended. It will point to the data
199          * elements above, so you can retrieve the response from there.
200          */
201         struct object_info info;
202
203         /*
204          * This flag will be true if the requested batch format and options
205          * don't require us to call sha1_object_info, which can then be
206          * optimized out.
207          */
208         unsigned skip_object_info : 1;
209 };
210
211 static int is_atom(const char *atom, const char *s, int slen)
212 {
213         int alen = strlen(atom);
214         return alen == slen && !memcmp(atom, s, alen);
215 }
216
217 static void expand_atom(struct strbuf *sb, const char *atom, int len,
218                         void *vdata)
219 {
220         struct expand_data *data = vdata;
221
222         if (is_atom("objectname", atom, len)) {
223                 if (!data->mark_query)
224                         strbuf_addstr(sb, oid_to_hex(&data->oid));
225         } else if (is_atom("objecttype", atom, len)) {
226                 if (data->mark_query)
227                         data->info.typep = &data->type;
228                 else
229                         strbuf_addstr(sb, typename(data->type));
230         } else if (is_atom("objectsize", atom, len)) {
231                 if (data->mark_query)
232                         data->info.sizep = &data->size;
233                 else
234                         strbuf_addf(sb, "%lu", data->size);
235         } else if (is_atom("objectsize:disk", atom, len)) {
236                 if (data->mark_query)
237                         data->info.disk_sizep = &data->disk_size;
238                 else
239                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
240         } else if (is_atom("rest", atom, len)) {
241                 if (data->mark_query)
242                         data->split_on_whitespace = 1;
243                 else if (data->rest)
244                         strbuf_addstr(sb, data->rest);
245         } else if (is_atom("deltabase", atom, len)) {
246                 if (data->mark_query)
247                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
248                 else
249                         strbuf_addstr(sb,
250                                       oid_to_hex(&data->delta_base_oid));
251         } else
252                 die("unknown format element: %.*s", len, atom);
253 }
254
255 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
256 {
257         const char *end;
258
259         if (*start != '(')
260                 return 0;
261         end = strchr(start + 1, ')');
262         if (!end)
263                 die("format element '%s' does not end in ')'", start);
264
265         expand_atom(sb, start + 1, end - start - 1, data);
266
267         return end - start + 1;
268 }
269
270 static void batch_write(struct batch_options *opt, const void *data, int len)
271 {
272         if (opt->buffer_output) {
273                 if (fwrite(data, 1, len, stdout) != len)
274                         die_errno("unable to write to stdout");
275         } else
276                 write_or_die(1, data, len);
277 }
278
279 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
280 {
281         const struct object_id *oid = &data->oid;
282
283         assert(data->info.typep);
284
285         if (data->type == OBJ_BLOB) {
286                 if (opt->buffer_output)
287                         fflush(stdout);
288                 if (opt->cmdmode) {
289                         char *contents;
290                         unsigned long size;
291
292                         if (!data->rest)
293                                 die("missing path for '%s'", oid_to_hex(oid));
294
295                         if (opt->cmdmode == 'w') {
296                                 if (filter_object(data->rest, 0100644, oid,
297                                                   &contents, &size))
298                                         die("could not convert '%s' %s",
299                                             oid_to_hex(oid), data->rest);
300                         } else if (opt->cmdmode == 'c') {
301                                 enum object_type type;
302                                 if (!textconv_object(data->rest, 0100644, oid,
303                                                      1, &contents, &size))
304                                         contents = read_sha1_file(oid->hash, &type,
305                                                                   &size);
306                                 if (!contents)
307                                         die("could not convert '%s' %s",
308                                             oid_to_hex(oid), data->rest);
309                         } else
310                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
311                         batch_write(opt, contents, size);
312                         free(contents);
313                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
314                         die("unable to stream %s to stdout", oid_to_hex(oid));
315         }
316         else {
317                 enum object_type type;
318                 unsigned long size;
319                 void *contents;
320
321                 contents = read_sha1_file(oid->hash, &type, &size);
322                 if (!contents)
323                         die("object %s disappeared", oid_to_hex(oid));
324                 if (type != data->type)
325                         die("object %s changed type!?", oid_to_hex(oid));
326                 if (data->info.sizep && size != data->size)
327                         die("object %s changed size!?", oid_to_hex(oid));
328
329                 batch_write(opt, contents, size);
330                 free(contents);
331         }
332 }
333
334 static void batch_object_write(const char *obj_name, struct batch_options *opt,
335                                struct expand_data *data)
336 {
337         struct strbuf buf = STRBUF_INIT;
338
339         if (!data->skip_object_info &&
340             sha1_object_info_extended(data->oid.hash, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
341                 printf("%s missing\n",
342                        obj_name ? obj_name : oid_to_hex(&data->oid));
343                 fflush(stdout);
344                 return;
345         }
346
347         strbuf_expand(&buf, opt->format, expand_format, data);
348         strbuf_addch(&buf, '\n');
349         batch_write(opt, buf.buf, buf.len);
350         strbuf_release(&buf);
351
352         if (opt->print_contents) {
353                 print_object_or_die(opt, data);
354                 batch_write(opt, "\n", 1);
355         }
356 }
357
358 static void batch_one_object(const char *obj_name, struct batch_options *opt,
359                              struct expand_data *data)
360 {
361         struct object_context ctx;
362         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
363         enum follow_symlinks_result result;
364
365         result = get_sha1_with_context(obj_name, flags, data->oid.hash, &ctx);
366         if (result != FOUND) {
367                 switch (result) {
368                 case MISSING_OBJECT:
369                         printf("%s missing\n", obj_name);
370                         break;
371                 case DANGLING_SYMLINK:
372                         printf("dangling %"PRIuMAX"\n%s\n",
373                                (uintmax_t)strlen(obj_name), obj_name);
374                         break;
375                 case SYMLINK_LOOP:
376                         printf("loop %"PRIuMAX"\n%s\n",
377                                (uintmax_t)strlen(obj_name), obj_name);
378                         break;
379                 case NOT_DIR:
380                         printf("notdir %"PRIuMAX"\n%s\n",
381                                (uintmax_t)strlen(obj_name), obj_name);
382                         break;
383                 default:
384                         die("BUG: unknown get_sha1_with_context result %d\n",
385                                result);
386                         break;
387                 }
388                 fflush(stdout);
389                 return;
390         }
391
392         if (ctx.mode == 0) {
393                 printf("symlink %"PRIuMAX"\n%s\n",
394                        (uintmax_t)ctx.symlink_path.len,
395                        ctx.symlink_path.buf);
396                 fflush(stdout);
397                 return;
398         }
399
400         batch_object_write(obj_name, opt, data);
401 }
402
403 struct object_cb_data {
404         struct batch_options *opt;
405         struct expand_data *expand;
406 };
407
408 static int batch_object_cb(const struct object_id *oid, void *vdata)
409 {
410         struct object_cb_data *data = vdata;
411         oidcpy(&data->expand->oid, oid);
412         batch_object_write(NULL, data->opt, data->expand);
413         return 0;
414 }
415
416 static int batch_loose_object(const struct object_id *oid,
417                               const char *path,
418                               void *data)
419 {
420         oid_array_append(data, oid);
421         return 0;
422 }
423
424 static int batch_packed_object(const struct object_id *oid,
425                                struct packed_git *pack,
426                                uint32_t pos,
427                                void *data)
428 {
429         oid_array_append(data, oid);
430         return 0;
431 }
432
433 static int batch_objects(struct batch_options *opt)
434 {
435         struct strbuf buf = STRBUF_INIT;
436         struct expand_data data;
437         int save_warning;
438         int retval = 0;
439
440         if (!opt->format)
441                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
442
443         /*
444          * Expand once with our special mark_query flag, which will prime the
445          * object_info to be handed to sha1_object_info_extended for each
446          * object.
447          */
448         memset(&data, 0, sizeof(data));
449         data.mark_query = 1;
450         strbuf_expand(&buf, opt->format, expand_format, &data);
451         data.mark_query = 0;
452         if (opt->cmdmode)
453                 data.split_on_whitespace = 1;
454
455         if (opt->all_objects) {
456                 struct object_info empty = OBJECT_INFO_INIT;
457                 if (!memcmp(&data.info, &empty, sizeof(empty)))
458                         data.skip_object_info = 1;
459         }
460
461         /*
462          * If we are printing out the object, then always fill in the type,
463          * since we will want to decide whether or not to stream.
464          */
465         if (opt->print_contents)
466                 data.info.typep = &data.type;
467
468         if (opt->all_objects) {
469                 struct oid_array sa = OID_ARRAY_INIT;
470                 struct object_cb_data cb;
471
472                 for_each_loose_object(batch_loose_object, &sa, 0);
473                 for_each_packed_object(batch_packed_object, &sa, 0);
474
475                 cb.opt = opt;
476                 cb.expand = &data;
477                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
478
479                 oid_array_clear(&sa);
480                 return 0;
481         }
482
483         /*
484          * We are going to call get_sha1 on a potentially very large number of
485          * objects. In most large cases, these will be actual object sha1s. The
486          * cost to double-check that each one is not also a ref (just so we can
487          * warn) ends up dwarfing the actual cost of the object lookups
488          * themselves. We can work around it by just turning off the warning.
489          */
490         save_warning = warn_on_object_refname_ambiguity;
491         warn_on_object_refname_ambiguity = 0;
492
493         while (strbuf_getline(&buf, stdin) != EOF) {
494                 if (data.split_on_whitespace) {
495                         /*
496                          * Split at first whitespace, tying off the beginning
497                          * of the string and saving the remainder (or NULL) in
498                          * data.rest.
499                          */
500                         char *p = strpbrk(buf.buf, " \t");
501                         if (p) {
502                                 while (*p && strchr(" \t", *p))
503                                         *p++ = '\0';
504                         }
505                         data.rest = p;
506                 }
507
508                 batch_one_object(buf.buf, opt, &data);
509         }
510
511         strbuf_release(&buf);
512         warn_on_object_refname_ambiguity = save_warning;
513         return retval;
514 }
515
516 static const char * const cat_file_usage[] = {
517         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
518         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
519         NULL
520 };
521
522 static int git_cat_file_config(const char *var, const char *value, void *cb)
523 {
524         if (userdiff_config(var, value) < 0)
525                 return -1;
526
527         return git_default_config(var, value, cb);
528 }
529
530 static int batch_option_callback(const struct option *opt,
531                                  const char *arg,
532                                  int unset)
533 {
534         struct batch_options *bo = opt->value;
535
536         if (bo->enabled) {
537                 return 1;
538         }
539
540         bo->enabled = 1;
541         bo->print_contents = !strcmp(opt->long_name, "batch");
542         bo->format = arg;
543
544         return 0;
545 }
546
547 int cmd_cat_file(int argc, const char **argv, const char *prefix)
548 {
549         int opt = 0;
550         const char *exp_type = NULL, *obj_name = NULL;
551         struct batch_options batch = {0};
552         int unknown_type = 0;
553
554         const struct option options[] = {
555                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
556                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
557                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
558                 OPT_CMDMODE('e', NULL, &opt,
559                             N_("exit with zero when there's no error"), 'e'),
560                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
561                 OPT_CMDMODE(0, "textconv", &opt,
562                             N_("for blob objects, run textconv on object's content"), 'c'),
563                 OPT_CMDMODE(0, "filters", &opt,
564                             N_("for blob objects, run filters on object's content"), 'w'),
565                 OPT_STRING(0, "path", &force_path, N_("blob"),
566                            N_("use a specific path for --textconv/--filters")),
567                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
568                           N_("allow -s and -t to work with broken/corrupt objects")),
569                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
570                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
571                         N_("show info and content of objects fed from the standard input"),
572                         PARSE_OPT_OPTARG, batch_option_callback },
573                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
574                         N_("show info about objects fed from the standard input"),
575                         PARSE_OPT_OPTARG, batch_option_callback },
576                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
577                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
578                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
579                          N_("show all objects with --batch or --batch-check")),
580                 OPT_END()
581         };
582
583         git_config(git_cat_file_config, NULL);
584
585         batch.buffer_output = -1;
586         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
587
588         if (opt) {
589                 if (batch.enabled && (opt == 'c' || opt == 'w'))
590                         batch.cmdmode = opt;
591                 else if (argc == 1)
592                         obj_name = argv[0];
593                 else
594                         usage_with_options(cat_file_usage, options);
595         }
596         if (!opt && !batch.enabled) {
597                 if (argc == 2) {
598                         exp_type = argv[0];
599                         obj_name = argv[1];
600                 } else
601                         usage_with_options(cat_file_usage, options);
602         }
603         if (batch.enabled) {
604                 if (batch.cmdmode != opt || argc)
605                         usage_with_options(cat_file_usage, options);
606                 if (batch.cmdmode && batch.all_objects)
607                         die("--batch-all-objects cannot be combined with "
608                             "--textconv nor with --filters");
609         }
610
611         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
612                 usage_with_options(cat_file_usage, options);
613         }
614
615         if (force_path && opt != 'c' && opt != 'w') {
616                 error("--path=<path> needs --textconv or --filters");
617                 usage_with_options(cat_file_usage, options);
618         }
619
620         if (force_path && batch.enabled) {
621                 error("--path=<path> incompatible with --batch");
622                 usage_with_options(cat_file_usage, options);
623         }
624
625         if (batch.buffer_output < 0)
626                 batch.buffer_output = batch.all_objects;
627
628         if (batch.enabled)
629                 return batch_objects(&batch);
630
631         if (unknown_type && opt != 't' && opt != 's')
632                 die("git cat-file --allow-unknown-type: use with -s or -t");
633         return cat_one_file(opt, exp_type, obj_name, unknown_type);
634 }