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