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