Document the underlying protocol used by shallow repositories and --depth commands.
[git] / git.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "exec_cmd.h"
4 #include "help.h"
5 #include "quote.h"
6 #include "run-command.h"
7
8 const char git_usage_string[] =
9         "git [--version] [--exec-path[=<path>]] [--html-path]\n"
10         "           [-p|--paginate|--no-pager] [--no-replace-objects]\n"
11         "           [--bare] [--git-dir=<path>] [--work-tree=<path>]\n"
12         "           [-c name=value] [--help]\n"
13         "           <command> [<args>]";
14
15 const char git_more_info_string[] =
16         "See 'git help <command>' for more information on a specific command.";
17
18 static struct startup_info git_startup_info;
19 static int use_pager = -1;
20 struct pager_config {
21         const char *cmd;
22         int want;
23         char *value;
24 };
25
26 static int pager_command_config(const char *var, const char *value, void *data)
27 {
28         struct pager_config *c = data;
29         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd)) {
30                 int b = git_config_maybe_bool(var, value);
31                 if (b >= 0)
32                         c->want = b;
33                 else {
34                         c->want = 1;
35                         c->value = xstrdup(value);
36                 }
37         }
38         return 0;
39 }
40
41 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
42 int check_pager_config(const char *cmd)
43 {
44         struct pager_config c;
45         c.cmd = cmd;
46         c.want = -1;
47         c.value = NULL;
48         git_config(pager_command_config, &c);
49         if (c.value)
50                 pager_program = c.value;
51         return c.want;
52 }
53
54 static void commit_pager_choice(void) {
55         switch (use_pager) {
56         case 0:
57                 setenv("GIT_PAGER", "cat", 1);
58                 break;
59         case 1:
60                 setup_pager();
61                 break;
62         default:
63                 break;
64         }
65 }
66
67 static int handle_options(const char ***argv, int *argc, int *envchanged)
68 {
69         const char **orig_argv = *argv;
70
71         while (*argc > 0) {
72                 const char *cmd = (*argv)[0];
73                 if (cmd[0] != '-')
74                         break;
75
76                 /*
77                  * For legacy reasons, the "version" and "help"
78                  * commands can be written with "--" prepended
79                  * to make them look like flags.
80                  */
81                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
82                         break;
83
84                 /*
85                  * Check remaining flags.
86                  */
87                 if (!prefixcmp(cmd, "--exec-path")) {
88                         cmd += 11;
89                         if (*cmd == '=')
90                                 git_set_argv_exec_path(cmd + 1);
91                         else {
92                                 puts(git_exec_path());
93                                 exit(0);
94                         }
95                 } else if (!strcmp(cmd, "--html-path")) {
96                         puts(system_path(GIT_HTML_PATH));
97                         exit(0);
98                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
99                         use_pager = 1;
100                 } else if (!strcmp(cmd, "--no-pager")) {
101                         use_pager = 0;
102                         if (envchanged)
103                                 *envchanged = 1;
104                 } else if (!strcmp(cmd, "--no-replace-objects")) {
105                         read_replace_refs = 0;
106                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
107                         if (envchanged)
108                                 *envchanged = 1;
109                 } else if (!strcmp(cmd, "--git-dir")) {
110                         if (*argc < 2) {
111                                 fprintf(stderr, "No directory given for --git-dir.\n" );
112                                 usage(git_usage_string);
113                         }
114                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
115                         if (envchanged)
116                                 *envchanged = 1;
117                         (*argv)++;
118                         (*argc)--;
119                 } else if (!prefixcmp(cmd, "--git-dir=")) {
120                         setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
121                         if (envchanged)
122                                 *envchanged = 1;
123                 } else if (!strcmp(cmd, "--work-tree")) {
124                         if (*argc < 2) {
125                                 fprintf(stderr, "No directory given for --work-tree.\n" );
126                                 usage(git_usage_string);
127                         }
128                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
129                         if (envchanged)
130                                 *envchanged = 1;
131                         (*argv)++;
132                         (*argc)--;
133                 } else if (!prefixcmp(cmd, "--work-tree=")) {
134                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
135                         if (envchanged)
136                                 *envchanged = 1;
137                 } else if (!strcmp(cmd, "--bare")) {
138                         static char git_dir[PATH_MAX+1];
139                         is_bare_repository_cfg = 1;
140                         setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
141                         if (envchanged)
142                                 *envchanged = 1;
143                 } else if (!strcmp(cmd, "-c")) {
144                         if (*argc < 2) {
145                                 fprintf(stderr, "-c expects a configuration string\n" );
146                                 usage(git_usage_string);
147                         }
148                         git_config_push_parameter((*argv)[1]);
149                         (*argv)++;
150                         (*argc)--;
151                 } else {
152                         fprintf(stderr, "Unknown option: %s\n", cmd);
153                         usage(git_usage_string);
154                 }
155
156                 (*argv)++;
157                 (*argc)--;
158         }
159         return (*argv) - orig_argv;
160 }
161
162 static int handle_alias(int *argcp, const char ***argv)
163 {
164         int envchanged = 0, ret = 0, saved_errno = errno;
165         const char *subdir;
166         int count, option_count;
167         const char **new_argv;
168         const char *alias_command;
169         char *alias_string;
170         int unused_nongit;
171
172         subdir = setup_git_directory_gently(&unused_nongit);
173
174         alias_command = (*argv)[0];
175         alias_string = alias_lookup(alias_command);
176         if (alias_string) {
177                 if (alias_string[0] == '!') {
178                         const char **alias_argv;
179                         int argc = *argcp, i;
180
181                         commit_pager_choice();
182
183                         /* build alias_argv */
184                         alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 1));
185                         alias_argv[0] = alias_string + 1;
186                         for (i = 1; i < argc; ++i)
187                                 alias_argv[i] = (*argv)[i];
188                         alias_argv[argc] = NULL;
189
190                         ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
191                         if (ret >= 0)   /* normal exit */
192                                 exit(ret);
193
194                         die_errno("While expanding alias '%s': '%s'",
195                             alias_command, alias_string + 1);
196                 }
197                 count = split_cmdline(alias_string, &new_argv);
198                 if (count < 0)
199                         die("Bad alias.%s string: %s", alias_command,
200                             split_cmdline_strerror(count));
201                 option_count = handle_options(&new_argv, &count, &envchanged);
202                 if (envchanged)
203                         die("alias '%s' changes environment variables\n"
204                                  "You can use '!git' in the alias to do this.",
205                                  alias_command);
206                 memmove(new_argv - option_count, new_argv,
207                                 count * sizeof(char *));
208                 new_argv -= option_count;
209
210                 if (count < 1)
211                         die("empty alias for %s", alias_command);
212
213                 if (!strcmp(alias_command, new_argv[0]))
214                         die("recursive alias: %s", alias_command);
215
216                 trace_argv_printf(new_argv,
217                                   "trace: alias expansion: %s =>",
218                                   alias_command);
219
220                 new_argv = xrealloc(new_argv, sizeof(char *) *
221                                     (count + *argcp));
222                 /* insert after command name */
223                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
224
225                 *argv = new_argv;
226                 *argcp += count - 1;
227
228                 ret = 1;
229         }
230
231         if (subdir && chdir(subdir))
232                 die_errno("Cannot change to '%s'", subdir);
233
234         errno = saved_errno;
235
236         return ret;
237 }
238
239 const char git_version_string[] = GIT_VERSION;
240
241 #define RUN_SETUP               (1<<0)
242 #define RUN_SETUP_GENTLY        (1<<1)
243 #define USE_PAGER               (1<<2)
244 /*
245  * require working tree to be present -- anything uses this needs
246  * RUN_SETUP for reading from the configuration file.
247  */
248 #define NEED_WORK_TREE          (1<<3)
249
250 struct cmd_struct {
251         const char *cmd;
252         int (*fn)(int, const char **, const char *);
253         int option;
254 };
255
256 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
257 {
258         int status, help;
259         struct stat st;
260         const char *prefix;
261
262         prefix = NULL;
263         help = argc == 2 && !strcmp(argv[1], "-h");
264         if (!help) {
265                 if (p->option & RUN_SETUP)
266                         prefix = setup_git_directory();
267                 if (p->option & RUN_SETUP_GENTLY) {
268                         int nongit_ok;
269                         prefix = setup_git_directory_gently(&nongit_ok);
270                 }
271
272                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
273                         use_pager = check_pager_config(p->cmd);
274                 if (use_pager == -1 && p->option & USE_PAGER)
275                         use_pager = 1;
276
277                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
278                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
279                         trace_repo_setup(prefix);
280         }
281         commit_pager_choice();
282
283         if (!help && p->option & NEED_WORK_TREE)
284                 setup_work_tree();
285
286         trace_argv_printf(argv, "trace: built-in: git");
287
288         status = p->fn(argc, argv, prefix);
289         if (status)
290                 return status;
291
292         /* Somebody closed stdout? */
293         if (fstat(fileno(stdout), &st))
294                 return 0;
295         /* Ignore write errors for pipes and sockets.. */
296         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
297                 return 0;
298
299         /* Check for ENOSPC and EIO errors.. */
300         if (fflush(stdout))
301                 die_errno("write failure on standard output");
302         if (ferror(stdout))
303                 die("unknown write failure on standard output");
304         if (fclose(stdout))
305                 die_errno("close failed on standard output");
306         return 0;
307 }
308
309 static void handle_internal_command(int argc, const char **argv)
310 {
311         const char *cmd = argv[0];
312         static struct cmd_struct commands[] = {
313                 { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
314                 { "annotate", cmd_annotate, RUN_SETUP },
315                 { "apply", cmd_apply, RUN_SETUP_GENTLY },
316                 { "archive", cmd_archive },
317                 { "bisect--helper", cmd_bisect__helper, RUN_SETUP | NEED_WORK_TREE },
318                 { "blame", cmd_blame, RUN_SETUP },
319                 { "branch", cmd_branch, RUN_SETUP },
320                 { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
321                 { "cat-file", cmd_cat_file, RUN_SETUP },
322                 { "check-attr", cmd_check_attr, RUN_SETUP },
323                 { "check-ref-format", cmd_check_ref_format },
324                 { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
325                 { "checkout-index", cmd_checkout_index,
326                         RUN_SETUP | NEED_WORK_TREE},
327                 { "cherry", cmd_cherry, RUN_SETUP },
328                 { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
329                 { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
330                 { "clone", cmd_clone },
331                 { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
332                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
333                 { "config", cmd_config, RUN_SETUP_GENTLY },
334                 { "count-objects", cmd_count_objects, RUN_SETUP },
335                 { "describe", cmd_describe, RUN_SETUP },
336                 { "diff", cmd_diff },
337                 { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
338                 { "diff-index", cmd_diff_index, RUN_SETUP },
339                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
340                 { "fast-export", cmd_fast_export, RUN_SETUP },
341                 { "fetch", cmd_fetch, RUN_SETUP },
342                 { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
343                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
344                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
345                 { "format-patch", cmd_format_patch, RUN_SETUP },
346                 { "fsck", cmd_fsck, RUN_SETUP },
347                 { "fsck-objects", cmd_fsck, RUN_SETUP },
348                 { "gc", cmd_gc, RUN_SETUP },
349                 { "get-tar-commit-id", cmd_get_tar_commit_id },
350                 { "grep", cmd_grep, RUN_SETUP_GENTLY },
351                 { "hash-object", cmd_hash_object },
352                 { "help", cmd_help },
353                 { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
354                 { "init", cmd_init_db },
355                 { "init-db", cmd_init_db },
356                 { "log", cmd_log, RUN_SETUP },
357                 { "ls-files", cmd_ls_files, RUN_SETUP },
358                 { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
359                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
360                 { "mailinfo", cmd_mailinfo },
361                 { "mailsplit", cmd_mailsplit },
362                 { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
363                 { "merge-base", cmd_merge_base, RUN_SETUP },
364                 { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
365                 { "merge-index", cmd_merge_index, RUN_SETUP },
366                 { "merge-ours", cmd_merge_ours, RUN_SETUP },
367                 { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
368                 { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
369                 { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
370                 { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
371                 { "merge-tree", cmd_merge_tree, RUN_SETUP },
372                 { "mktag", cmd_mktag, RUN_SETUP },
373                 { "mktree", cmd_mktree, RUN_SETUP },
374                 { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
375                 { "name-rev", cmd_name_rev, RUN_SETUP },
376                 { "notes", cmd_notes, RUN_SETUP },
377                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
378                 { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
379                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
380                 { "patch-id", cmd_patch_id },
381                 { "peek-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
382                 { "pickaxe", cmd_blame, RUN_SETUP },
383                 { "prune", cmd_prune, RUN_SETUP },
384                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
385                 { "push", cmd_push, RUN_SETUP },
386                 { "read-tree", cmd_read_tree, RUN_SETUP },
387                 { "receive-pack", cmd_receive_pack },
388                 { "reflog", cmd_reflog, RUN_SETUP },
389                 { "remote", cmd_remote, RUN_SETUP },
390                 { "remote-ext", cmd_remote_ext },
391                 { "remote-fd", cmd_remote_fd },
392                 { "replace", cmd_replace, RUN_SETUP },
393                 { "repo-config", cmd_repo_config, RUN_SETUP_GENTLY },
394                 { "rerere", cmd_rerere, RUN_SETUP },
395                 { "reset", cmd_reset, RUN_SETUP },
396                 { "rev-list", cmd_rev_list, RUN_SETUP },
397                 { "rev-parse", cmd_rev_parse },
398                 { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
399                 { "rm", cmd_rm, RUN_SETUP },
400                 { "send-pack", cmd_send_pack, RUN_SETUP },
401                 { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
402                 { "show", cmd_show, RUN_SETUP },
403                 { "show-branch", cmd_show_branch, RUN_SETUP },
404                 { "show-ref", cmd_show_ref, RUN_SETUP },
405                 { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
406                 { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
407                 { "stripspace", cmd_stripspace },
408                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
409                 { "tag", cmd_tag, RUN_SETUP },
410                 { "tar-tree", cmd_tar_tree },
411                 { "unpack-file", cmd_unpack_file, RUN_SETUP },
412                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
413                 { "update-index", cmd_update_index, RUN_SETUP },
414                 { "update-ref", cmd_update_ref, RUN_SETUP },
415                 { "update-server-info", cmd_update_server_info, RUN_SETUP },
416                 { "upload-archive", cmd_upload_archive },
417                 { "var", cmd_var, RUN_SETUP_GENTLY },
418                 { "verify-pack", cmd_verify_pack },
419                 { "verify-tag", cmd_verify_tag, RUN_SETUP },
420                 { "version", cmd_version },
421                 { "whatchanged", cmd_whatchanged, RUN_SETUP },
422                 { "write-tree", cmd_write_tree, RUN_SETUP },
423         };
424         int i;
425         static const char ext[] = STRIP_EXTENSION;
426
427         if (sizeof(ext) > 1) {
428                 i = strlen(argv[0]) - strlen(ext);
429                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
430                         char *argv0 = xstrdup(argv[0]);
431                         argv[0] = cmd = argv0;
432                         argv0[i] = '\0';
433                 }
434         }
435
436         /* Turn "git cmd --help" into "git help cmd" */
437         if (argc > 1 && !strcmp(argv[1], "--help")) {
438                 argv[1] = argv[0];
439                 argv[0] = cmd = "help";
440         }
441
442         for (i = 0; i < ARRAY_SIZE(commands); i++) {
443                 struct cmd_struct *p = commands+i;
444                 if (strcmp(p->cmd, cmd))
445                         continue;
446                 exit(run_builtin(p, argc, argv));
447         }
448 }
449
450 static void execv_dashed_external(const char **argv)
451 {
452         struct strbuf cmd = STRBUF_INIT;
453         const char *tmp;
454         int status;
455
456         commit_pager_choice();
457
458         strbuf_addf(&cmd, "git-%s", argv[0]);
459
460         /*
461          * argv[0] must be the git command, but the argv array
462          * belongs to the caller, and may be reused in
463          * subsequent loop iterations. Save argv[0] and
464          * restore it on error.
465          */
466         tmp = argv[0];
467         argv[0] = cmd.buf;
468
469         trace_argv_printf(argv, "trace: exec:");
470
471         /*
472          * if we fail because the command is not found, it is
473          * OK to return. Otherwise, we just pass along the status code.
474          */
475         status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
476         if (status >= 0 || errno != ENOENT)
477                 exit(status);
478
479         argv[0] = tmp;
480
481         strbuf_release(&cmd);
482 }
483
484 static int run_argv(int *argcp, const char ***argv)
485 {
486         int done_alias = 0;
487
488         while (1) {
489                 /* See if it's an internal command */
490                 handle_internal_command(*argcp, *argv);
491
492                 /* .. then try the external ones */
493                 execv_dashed_external(*argv);
494
495                 /* It could be an alias -- this works around the insanity
496                  * of overriding "git log" with "git show" by having
497                  * alias.log = show
498                  */
499                 if (done_alias || !handle_alias(argcp, argv))
500                         break;
501                 done_alias = 1;
502         }
503
504         return done_alias;
505 }
506
507
508 int main(int argc, const char **argv)
509 {
510         const char *cmd;
511
512         startup_info = &git_startup_info;
513
514         cmd = git_extract_argv0_path(argv[0]);
515         if (!cmd)
516                 cmd = "git-help";
517
518         /*
519          * "git-xxxx" is the same as "git xxxx", but we obviously:
520          *
521          *  - cannot take flags in between the "git" and the "xxxx".
522          *  - cannot execute it externally (since it would just do
523          *    the same thing over again)
524          *
525          * So we just directly call the internal command handler, and
526          * die if that one cannot handle it.
527          */
528         if (!prefixcmp(cmd, "git-")) {
529                 cmd += 4;
530                 argv[0] = cmd;
531                 handle_internal_command(argc, argv);
532                 die("cannot handle %s internally", cmd);
533         }
534
535         /* Look for flags.. */
536         argv++;
537         argc--;
538         handle_options(&argv, &argc, NULL);
539         if (argc > 0) {
540                 if (!prefixcmp(argv[0], "--"))
541                         argv[0] += 2;
542         } else {
543                 /* The user didn't specify a command; give them help */
544                 commit_pager_choice();
545                 printf("usage: %s\n\n", git_usage_string);
546                 list_common_cmds_help();
547                 printf("\n%s\n", git_more_info_string);
548                 exit(1);
549         }
550         cmd = argv[0];
551
552         /*
553          * We use PATH to find git commands, but we prepend some higher
554          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
555          * environment, and the $(gitexecdir) from the Makefile at build
556          * time.
557          */
558         setup_path();
559
560         while (1) {
561                 static int done_help = 0;
562                 static int was_alias = 0;
563                 was_alias = run_argv(&argc, &argv);
564                 if (errno != ENOENT)
565                         break;
566                 if (was_alias) {
567                         fprintf(stderr, "Expansion of alias '%s' failed; "
568                                 "'%s' is not a git command\n",
569                                 cmd, argv[0]);
570                         exit(1);
571                 }
572                 if (!done_help) {
573                         cmd = argv[0] = help_unknown_cmd(cmd);
574                         done_help = 1;
575                 } else
576                         break;
577         }
578
579         fprintf(stderr, "Failed to run command '%s': %s\n",
580                 cmd, strerror(errno));
581
582         return 1;
583 }