Merge branch 'ls/filter-process-delayed' into jt/subprocess-handshake
[git] / git.c
1 #include "builtin.h"
2 #include "config.h"
3 #include "exec_cmd.h"
4 #include "help.h"
5 #include "run-command.h"
6
7 const char git_usage_string[] =
8         "git [--version] [--help] [-C <path>] [-c name=value]\n"
9         "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
10         "           [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
11         "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
12         "           <command> [<args>]";
13
14 const char git_more_info_string[] =
15         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
16            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
17            "to read about a specific subcommand or concept.");
18
19 static int use_pager = -1;
20
21 static void list_builtins(void);
22
23 static void commit_pager_choice(void) {
24         switch (use_pager) {
25         case 0:
26                 setenv("GIT_PAGER", "cat", 1);
27                 break;
28         case 1:
29                 setup_pager();
30                 break;
31         default:
32                 break;
33         }
34 }
35
36 static int handle_options(const char ***argv, int *argc, int *envchanged)
37 {
38         const char **orig_argv = *argv;
39
40         while (*argc > 0) {
41                 const char *cmd = (*argv)[0];
42                 if (cmd[0] != '-')
43                         break;
44
45                 /*
46                  * For legacy reasons, the "version" and "help"
47                  * commands can be written with "--" prepended
48                  * to make them look like flags.
49                  */
50                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
51                         break;
52
53                 /*
54                  * Check remaining flags.
55                  */
56                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
57                         if (*cmd == '=')
58                                 git_set_argv_exec_path(cmd + 1);
59                         else {
60                                 puts(git_exec_path());
61                                 exit(0);
62                         }
63                 } else if (!strcmp(cmd, "--html-path")) {
64                         puts(system_path(GIT_HTML_PATH));
65                         exit(0);
66                 } else if (!strcmp(cmd, "--man-path")) {
67                         puts(system_path(GIT_MAN_PATH));
68                         exit(0);
69                 } else if (!strcmp(cmd, "--info-path")) {
70                         puts(system_path(GIT_INFO_PATH));
71                         exit(0);
72                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
73                         use_pager = 1;
74                 } else if (!strcmp(cmd, "--no-pager")) {
75                         use_pager = 0;
76                         if (envchanged)
77                                 *envchanged = 1;
78                 } else if (!strcmp(cmd, "--no-replace-objects")) {
79                         check_replace_refs = 0;
80                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
81                         if (envchanged)
82                                 *envchanged = 1;
83                 } else if (!strcmp(cmd, "--git-dir")) {
84                         if (*argc < 2) {
85                                 fprintf(stderr, "No directory given for --git-dir.\n" );
86                                 usage(git_usage_string);
87                         }
88                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
89                         if (envchanged)
90                                 *envchanged = 1;
91                         (*argv)++;
92                         (*argc)--;
93                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
94                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
95                         if (envchanged)
96                                 *envchanged = 1;
97                 } else if (!strcmp(cmd, "--namespace")) {
98                         if (*argc < 2) {
99                                 fprintf(stderr, "No namespace given for --namespace.\n" );
100                                 usage(git_usage_string);
101                         }
102                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
103                         if (envchanged)
104                                 *envchanged = 1;
105                         (*argv)++;
106                         (*argc)--;
107                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
108                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
109                         if (envchanged)
110                                 *envchanged = 1;
111                 } else if (!strcmp(cmd, "--work-tree")) {
112                         if (*argc < 2) {
113                                 fprintf(stderr, "No directory given for --work-tree.\n" );
114                                 usage(git_usage_string);
115                         }
116                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
117                         if (envchanged)
118                                 *envchanged = 1;
119                         (*argv)++;
120                         (*argc)--;
121                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
122                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
123                         if (envchanged)
124                                 *envchanged = 1;
125                 } else if (!strcmp(cmd, "--super-prefix")) {
126                         if (*argc < 2) {
127                                 fprintf(stderr, "No prefix given for --super-prefix.\n" );
128                                 usage(git_usage_string);
129                         }
130                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
131                         if (envchanged)
132                                 *envchanged = 1;
133                         (*argv)++;
134                         (*argc)--;
135                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
136                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
137                         if (envchanged)
138                                 *envchanged = 1;
139                 } else if (!strcmp(cmd, "--bare")) {
140                         char *cwd = xgetcwd();
141                         is_bare_repository_cfg = 1;
142                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
143                         free(cwd);
144                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
145                         if (envchanged)
146                                 *envchanged = 1;
147                 } else if (!strcmp(cmd, "-c")) {
148                         if (*argc < 2) {
149                                 fprintf(stderr, "-c expects a configuration string\n" );
150                                 usage(git_usage_string);
151                         }
152                         git_config_push_parameter((*argv)[1]);
153                         (*argv)++;
154                         (*argc)--;
155                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
156                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
157                         if (envchanged)
158                                 *envchanged = 1;
159                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
160                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
161                         if (envchanged)
162                                 *envchanged = 1;
163                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
164                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
165                         if (envchanged)
166                                 *envchanged = 1;
167                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
168                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
169                         if (envchanged)
170                                 *envchanged = 1;
171                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
172                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
173                         if (envchanged)
174                                 *envchanged = 1;
175                 } else if (!strcmp(cmd, "--shallow-file")) {
176                         (*argv)++;
177                         (*argc)--;
178                         set_alternate_shallow_file((*argv)[0], 1);
179                         if (envchanged)
180                                 *envchanged = 1;
181                 } else if (!strcmp(cmd, "-C")) {
182                         if (*argc < 2) {
183                                 fprintf(stderr, "No directory given for -C.\n" );
184                                 usage(git_usage_string);
185                         }
186                         if ((*argv)[1][0]) {
187                                 if (chdir((*argv)[1]))
188                                         die_errno("Cannot change to '%s'", (*argv)[1]);
189                                 if (envchanged)
190                                         *envchanged = 1;
191                         }
192                         (*argv)++;
193                         (*argc)--;
194                 } else if (!strcmp(cmd, "--list-builtins")) {
195                         list_builtins();
196                         exit(0);
197                 } else {
198                         fprintf(stderr, "Unknown option: %s\n", cmd);
199                         usage(git_usage_string);
200                 }
201
202                 (*argv)++;
203                 (*argc)--;
204         }
205         return (*argv) - orig_argv;
206 }
207
208 static int handle_alias(int *argcp, const char ***argv)
209 {
210         int envchanged = 0, ret = 0, saved_errno = errno;
211         int count, option_count;
212         const char **new_argv;
213         const char *alias_command;
214         char *alias_string;
215
216         alias_command = (*argv)[0];
217         alias_string = alias_lookup(alias_command);
218         if (alias_string) {
219                 if (alias_string[0] == '!') {
220                         struct child_process child = CHILD_PROCESS_INIT;
221                         int nongit_ok;
222
223                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
224                         setup_git_directory_gently(&nongit_ok);
225
226                         commit_pager_choice();
227
228                         child.use_shell = 1;
229                         argv_array_push(&child.args, alias_string + 1);
230                         argv_array_pushv(&child.args, (*argv) + 1);
231
232                         ret = run_command(&child);
233                         if (ret >= 0)   /* normal exit */
234                                 exit(ret);
235
236                         die_errno("While expanding alias '%s': '%s'",
237                             alias_command, alias_string + 1);
238                 }
239                 count = split_cmdline(alias_string, &new_argv);
240                 if (count < 0)
241                         die("Bad alias.%s string: %s", alias_command,
242                             split_cmdline_strerror(count));
243                 option_count = handle_options(&new_argv, &count, &envchanged);
244                 if (envchanged)
245                         die("alias '%s' changes environment variables\n"
246                                  "You can use '!git' in the alias to do this.",
247                                  alias_command);
248                 memmove(new_argv - option_count, new_argv,
249                                 count * sizeof(char *));
250                 new_argv -= option_count;
251
252                 if (count < 1)
253                         die("empty alias for %s", alias_command);
254
255                 if (!strcmp(alias_command, new_argv[0]))
256                         die("recursive alias: %s", alias_command);
257
258                 trace_argv_printf(new_argv,
259                                   "trace: alias expansion: %s =>",
260                                   alias_command);
261
262                 REALLOC_ARRAY(new_argv, count + *argcp);
263                 /* insert after command name */
264                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
265
266                 *argv = new_argv;
267                 *argcp += count - 1;
268
269                 ret = 1;
270         }
271
272         errno = saved_errno;
273
274         return ret;
275 }
276
277 #define RUN_SETUP               (1<<0)
278 #define RUN_SETUP_GENTLY        (1<<1)
279 #define USE_PAGER               (1<<2)
280 /*
281  * require working tree to be present -- anything uses this needs
282  * RUN_SETUP for reading from the configuration file.
283  */
284 #define NEED_WORK_TREE          (1<<3)
285 #define SUPPORT_SUPER_PREFIX    (1<<4)
286
287 struct cmd_struct {
288         const char *cmd;
289         int (*fn)(int, const char **, const char *);
290         int option;
291 };
292
293 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
294 {
295         int status, help;
296         struct stat st;
297         const char *prefix;
298
299         prefix = NULL;
300         help = argc == 2 && !strcmp(argv[1], "-h");
301         if (!help) {
302                 if (p->option & RUN_SETUP)
303                         prefix = setup_git_directory();
304                 else if (p->option & RUN_SETUP_GENTLY) {
305                         int nongit_ok;
306                         prefix = setup_git_directory_gently(&nongit_ok);
307                 }
308
309                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
310                         use_pager = check_pager_config(p->cmd);
311                 if (use_pager == -1 && p->option & USE_PAGER)
312                         use_pager = 1;
313
314                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
315                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
316                         trace_repo_setup(prefix);
317         }
318         commit_pager_choice();
319
320         if (!help && get_super_prefix()) {
321                 if (!(p->option & SUPPORT_SUPER_PREFIX))
322                         die("%s doesn't support --super-prefix", p->cmd);
323         }
324
325         if (!help && p->option & NEED_WORK_TREE)
326                 setup_work_tree();
327
328         trace_argv_printf(argv, "trace: built-in: git");
329
330         status = p->fn(argc, argv, prefix);
331         if (status)
332                 return status;
333
334         /* Somebody closed stdout? */
335         if (fstat(fileno(stdout), &st))
336                 return 0;
337         /* Ignore write errors for pipes and sockets.. */
338         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
339                 return 0;
340
341         /* Check for ENOSPC and EIO errors.. */
342         if (fflush(stdout))
343                 die_errno("write failure on standard output");
344         if (ferror(stdout))
345                 die("unknown write failure on standard output");
346         if (fclose(stdout))
347                 die_errno("close failed on standard output");
348         return 0;
349 }
350
351 static struct cmd_struct commands[] = {
352         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
353         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
354         { "annotate", cmd_annotate, RUN_SETUP },
355         { "apply", cmd_apply, RUN_SETUP_GENTLY },
356         { "archive", cmd_archive, RUN_SETUP_GENTLY },
357         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
358         { "blame", cmd_blame, RUN_SETUP },
359         { "branch", cmd_branch, RUN_SETUP },
360         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
361         { "cat-file", cmd_cat_file, RUN_SETUP },
362         { "check-attr", cmd_check_attr, RUN_SETUP },
363         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
364         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
365         { "check-ref-format", cmd_check_ref_format },
366         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
367         { "checkout-index", cmd_checkout_index,
368                 RUN_SETUP | NEED_WORK_TREE},
369         { "cherry", cmd_cherry, RUN_SETUP },
370         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
371         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
372         { "clone", cmd_clone },
373         { "column", cmd_column, RUN_SETUP_GENTLY },
374         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
375         { "commit-tree", cmd_commit_tree, RUN_SETUP },
376         { "config", cmd_config, RUN_SETUP_GENTLY },
377         { "count-objects", cmd_count_objects, RUN_SETUP },
378         { "credential", cmd_credential, RUN_SETUP_GENTLY },
379         { "describe", cmd_describe, RUN_SETUP },
380         { "diff", cmd_diff },
381         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
382         { "diff-index", cmd_diff_index, RUN_SETUP },
383         { "diff-tree", cmd_diff_tree, RUN_SETUP },
384         { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
385         { "fast-export", cmd_fast_export, RUN_SETUP },
386         { "fetch", cmd_fetch, RUN_SETUP },
387         { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
388         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
389         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
390         { "format-patch", cmd_format_patch, RUN_SETUP },
391         { "fsck", cmd_fsck, RUN_SETUP },
392         { "fsck-objects", cmd_fsck, RUN_SETUP },
393         { "gc", cmd_gc, RUN_SETUP },
394         { "get-tar-commit-id", cmd_get_tar_commit_id },
395         { "grep", cmd_grep, RUN_SETUP_GENTLY | SUPPORT_SUPER_PREFIX },
396         { "hash-object", cmd_hash_object },
397         { "help", cmd_help },
398         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
399         { "init", cmd_init_db },
400         { "init-db", cmd_init_db },
401         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
402         { "log", cmd_log, RUN_SETUP },
403         { "ls-files", cmd_ls_files, RUN_SETUP },
404         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
405         { "ls-tree", cmd_ls_tree, RUN_SETUP },
406         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
407         { "mailsplit", cmd_mailsplit },
408         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
409         { "merge-base", cmd_merge_base, RUN_SETUP },
410         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
411         { "merge-index", cmd_merge_index, RUN_SETUP },
412         { "merge-ours", cmd_merge_ours, RUN_SETUP },
413         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
414         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
415         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
416         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
417         { "merge-tree", cmd_merge_tree, RUN_SETUP },
418         { "mktag", cmd_mktag, RUN_SETUP },
419         { "mktree", cmd_mktree, RUN_SETUP },
420         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
421         { "name-rev", cmd_name_rev, RUN_SETUP },
422         { "notes", cmd_notes, RUN_SETUP },
423         { "pack-objects", cmd_pack_objects, RUN_SETUP },
424         { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
425         { "pack-refs", cmd_pack_refs, RUN_SETUP },
426         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
427         { "pickaxe", cmd_blame, RUN_SETUP },
428         { "prune", cmd_prune, RUN_SETUP },
429         { "prune-packed", cmd_prune_packed, RUN_SETUP },
430         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
431         { "push", cmd_push, RUN_SETUP },
432         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
433         { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
434         { "receive-pack", cmd_receive_pack },
435         { "reflog", cmd_reflog, RUN_SETUP },
436         { "remote", cmd_remote, RUN_SETUP },
437         { "remote-ext", cmd_remote_ext },
438         { "remote-fd", cmd_remote_fd },
439         { "repack", cmd_repack, RUN_SETUP },
440         { "replace", cmd_replace, RUN_SETUP },
441         { "rerere", cmd_rerere, RUN_SETUP },
442         { "reset", cmd_reset, RUN_SETUP },
443         { "rev-list", cmd_rev_list, RUN_SETUP },
444         { "rev-parse", cmd_rev_parse },
445         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
446         { "rm", cmd_rm, RUN_SETUP },
447         { "send-pack", cmd_send_pack, RUN_SETUP },
448         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
449         { "show", cmd_show, RUN_SETUP },
450         { "show-branch", cmd_show_branch, RUN_SETUP },
451         { "show-ref", cmd_show_ref, RUN_SETUP },
452         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
453         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
454         { "stripspace", cmd_stripspace },
455         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX},
456         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
457         { "tag", cmd_tag, RUN_SETUP },
458         { "unpack-file", cmd_unpack_file, RUN_SETUP },
459         { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
460         { "update-index", cmd_update_index, RUN_SETUP },
461         { "update-ref", cmd_update_ref, RUN_SETUP },
462         { "update-server-info", cmd_update_server_info, RUN_SETUP },
463         { "upload-archive", cmd_upload_archive },
464         { "upload-archive--writer", cmd_upload_archive_writer },
465         { "var", cmd_var, RUN_SETUP_GENTLY },
466         { "verify-commit", cmd_verify_commit, RUN_SETUP },
467         { "verify-pack", cmd_verify_pack },
468         { "verify-tag", cmd_verify_tag, RUN_SETUP },
469         { "version", cmd_version },
470         { "whatchanged", cmd_whatchanged, RUN_SETUP },
471         { "worktree", cmd_worktree, RUN_SETUP },
472         { "write-tree", cmd_write_tree, RUN_SETUP },
473 };
474
475 static struct cmd_struct *get_builtin(const char *s)
476 {
477         int i;
478         for (i = 0; i < ARRAY_SIZE(commands); i++) {
479                 struct cmd_struct *p = commands + i;
480                 if (!strcmp(s, p->cmd))
481                         return p;
482         }
483         return NULL;
484 }
485
486 int is_builtin(const char *s)
487 {
488         return !!get_builtin(s);
489 }
490
491 static void list_builtins(void)
492 {
493         int i;
494         for (i = 0; i < ARRAY_SIZE(commands); i++)
495                 printf("%s\n", commands[i].cmd);
496 }
497
498 #ifdef STRIP_EXTENSION
499 static void strip_extension(const char **argv)
500 {
501         size_t len;
502
503         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
504                 argv[0] = xmemdupz(argv[0], len);
505 }
506 #else
507 #define strip_extension(cmd)
508 #endif
509
510 static void handle_builtin(int argc, const char **argv)
511 {
512         struct argv_array args = ARGV_ARRAY_INIT;
513         const char *cmd;
514         struct cmd_struct *builtin;
515
516         strip_extension(argv);
517         cmd = argv[0];
518
519         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
520         if (argc > 1 && !strcmp(argv[1], "--help")) {
521                 int i;
522
523                 argv[1] = argv[0];
524                 argv[0] = cmd = "help";
525
526                 for (i = 0; i < argc; i++) {
527                         argv_array_push(&args, argv[i]);
528                         if (!i)
529                                 argv_array_push(&args, "--exclude-guides");
530                 }
531
532                 argc++;
533                 argv = args.argv;
534         }
535
536         builtin = get_builtin(cmd);
537         if (builtin)
538                 exit(run_builtin(builtin, argc, argv));
539         argv_array_clear(&args);
540 }
541
542 static void execv_dashed_external(const char **argv)
543 {
544         struct child_process cmd = CHILD_PROCESS_INIT;
545         int status;
546
547         if (get_super_prefix())
548                 die("%s doesn't support --super-prefix", argv[0]);
549
550         if (use_pager == -1)
551                 use_pager = check_pager_config(argv[0]);
552         commit_pager_choice();
553
554         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
555         argv_array_pushv(&cmd.args, argv + 1);
556         cmd.clean_on_exit = 1;
557         cmd.wait_after_clean = 1;
558         cmd.silent_exec_failure = 1;
559
560         trace_argv_printf(cmd.args.argv, "trace: exec:");
561
562         /*
563          * If we fail because the command is not found, it is
564          * OK to return. Otherwise, we just pass along the status code,
565          * or our usual generic code if we were not even able to exec
566          * the program.
567          */
568         status = run_command(&cmd);
569         if (status >= 0)
570                 exit(status);
571         else if (errno != ENOENT)
572                 exit(128);
573 }
574
575 static int run_argv(int *argcp, const char ***argv)
576 {
577         int done_alias = 0;
578
579         while (1) {
580                 /*
581                  * If we tried alias and futzed with our environment,
582                  * it no longer is safe to invoke builtins directly in
583                  * general.  We have to spawn them as dashed externals.
584                  *
585                  * NEEDSWORK: if we can figure out cases
586                  * where it is safe to do, we can avoid spawning a new
587                  * process.
588                  */
589                 if (!done_alias)
590                         handle_builtin(*argcp, *argv);
591
592                 /* .. then try the external ones */
593                 execv_dashed_external(*argv);
594
595                 /* It could be an alias -- this works around the insanity
596                  * of overriding "git log" with "git show" by having
597                  * alias.log = show
598                  */
599                 if (done_alias)
600                         break;
601                 if (!handle_alias(argcp, argv))
602                         break;
603                 done_alias = 1;
604         }
605
606         return done_alias;
607 }
608
609 int cmd_main(int argc, const char **argv)
610 {
611         const char *cmd;
612         int done_help = 0;
613
614         cmd = argv[0];
615         if (!cmd)
616                 cmd = "git-help";
617         else {
618                 const char *slash = find_last_dir_sep(cmd);
619                 if (slash)
620                         cmd = slash + 1;
621         }
622
623         trace_command_performance(argv);
624
625         /*
626          * "git-xxxx" is the same as "git xxxx", but we obviously:
627          *
628          *  - cannot take flags in between the "git" and the "xxxx".
629          *  - cannot execute it externally (since it would just do
630          *    the same thing over again)
631          *
632          * So we just directly call the builtin handler, and die if
633          * that one cannot handle it.
634          */
635         if (skip_prefix(cmd, "git-", &cmd)) {
636                 argv[0] = cmd;
637                 handle_builtin(argc, argv);
638                 die("cannot handle %s as a builtin", cmd);
639         }
640
641         /* Look for flags.. */
642         argv++;
643         argc--;
644         handle_options(&argv, &argc, NULL);
645         if (argc > 0) {
646                 /* translate --help and --version into commands */
647                 skip_prefix(argv[0], "--", &argv[0]);
648         } else {
649                 /* The user didn't specify a command; give them help */
650                 commit_pager_choice();
651                 printf("usage: %s\n\n", git_usage_string);
652                 list_common_cmds_help();
653                 printf("\n%s\n", _(git_more_info_string));
654                 exit(1);
655         }
656         cmd = argv[0];
657
658         /*
659          * We use PATH to find git commands, but we prepend some higher
660          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
661          * environment, and the $(gitexecdir) from the Makefile at build
662          * time.
663          */
664         setup_path();
665
666         while (1) {
667                 int was_alias = run_argv(&argc, &argv);
668                 if (errno != ENOENT)
669                         break;
670                 if (was_alias) {
671                         fprintf(stderr, "Expansion of alias '%s' failed; "
672                                 "'%s' is not a git command\n",
673                                 cmd, argv[0]);
674                         exit(1);
675                 }
676                 if (!done_help) {
677                         cmd = argv[0] = help_unknown_cmd(cmd);
678                         done_help = 1;
679                 } else
680                         break;
681         }
682
683         fprintf(stderr, "Failed to run command '%s': %s\n",
684                 cmd, strerror(errno));
685
686         return 1;
687 }