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 #include "alias.h"
   7
   8 #define RUN_SETUP               (1<<0)
   9 #define RUN_SETUP_GENTLY        (1<<1)
  10 #define USE_PAGER               (1<<2)
  11 /*
  12  * require working tree to be present -- anything uses this needs
  13  * RUN_SETUP for reading from the configuration file.
  14  */
  15 #define NEED_WORK_TREE          (1<<3)
  16 #define SUPPORT_SUPER_PREFIX    (1<<4)
  17 #define DELAY_PAGER_CONFIG      (1<<5)
  18 #define NO_PARSEOPT             (1<<6) /* parse-options is not used */
  19
  20 struct cmd_struct {
  21         const char *cmd;
  22         int (*fn)(int, const char **, const char *);
  23         unsigned int option;
  24 };
  25
  26 const char git_usage_string[] =
  27         N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
  28            "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  29            "           [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
  30            "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  31            "           <command> [<args>]");
  32
  33 const char git_more_info_string[] =
  34         N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  35            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  36            "to read about a specific subcommand or concept.");
  37
  38 static int use_pager = -1;
  39
  40 static void list_builtins(struct string_list *list, unsigned int exclude_option);
  41
  42 static int match_token(const char *spec, int len, const char *token)
  43 {
  44         int token_len = strlen(token);
  45
  46         return len == token_len && !strncmp(spec, token, token_len);
  47 }
  48
  49 static int list_cmds(const char *spec)
  50 {
  51         struct string_list list = STRING_LIST_INIT_DUP;
  52         int i;
  53
  54         while (*spec) {
  55                 const char *sep = strchrnul(spec, ',');
  56                 int len = sep - spec;
  57
  58                 if (match_token(spec, len, "builtins"))
  59                         list_builtins(&list, 0);
  60                 else if (match_token(spec, len, "main"))
  61                         list_all_main_cmds(&list);
  62                 else if (match_token(spec, len, "others"))
  63                         list_all_other_cmds(&list);
  64                 else if (len > 5 && !strncmp(spec, "list-", 5)) {
  65                         struct strbuf sb = STRBUF_INIT;
  66
  67                         strbuf_add(&sb, spec + 5, len - 5);
  68                         list_cmds_by_category(&list, sb.buf);
  69                         strbuf_release(&sb);
  70                 }
  71                 else
  72                         die(_("unsupported command listing type '%s'"), spec);
  73                 spec += len;
  74                 if (*spec == ',')
  75                         spec++;
  76         }
  77         for (i = 0; i < list.nr; i++)
  78                 puts(list.items[i].string);
  79         string_list_clear(&list, 0);
  80         return 0;
  81 }
  82
  83 static void commit_pager_choice(void) {
  84         switch (use_pager) {
  85         case 0:
  86                 setenv("GIT_PAGER", "cat", 1);
  87                 break;
  88         case 1:
  89                 setup_pager();
  90                 break;
  91         default:
  92                 break;
  93         }
  94 }
  95
  96 void setup_auto_pager(const char *cmd, int def)
  97 {
  98         if (use_pager != -1 || pager_in_use())
  99                 return;
 100         use_pager = check_pager_config(cmd);
 101         if (use_pager == -1)
 102                 use_pager = def;
 103         commit_pager_choice();
 104 }
 105
 106 static int handle_options(const char ***argv, int *argc, int *envchanged)
 107 {
 108         const char **orig_argv = *argv;
 109
 110         while (*argc > 0) {
 111                 const char *cmd = (*argv)[0];
 112                 if (cmd[0] != '-')
 113                         break;
 114
 115                 /*
 116                  * For legacy reasons, the "version" and "help"
 117                  * commands can be written with "--" prepended
 118                  * to make them look like flags.
 119                  */
 120                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 121                         break;
 122
 123                 /*
 124                  * Check remaining flags.
 125                  */
 126                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
 127                         if (*cmd == '=')
 128                                 git_set_argv_exec_path(cmd + 1);
 129                         else {
 130                                 puts(git_exec_path());
 131                                 exit(0);
 132                         }
 133                 } else if (!strcmp(cmd, "--html-path")) {
 134                         puts(system_path(GIT_HTML_PATH));
 135                         exit(0);
 136                 } else if (!strcmp(cmd, "--man-path")) {
 137                         puts(system_path(GIT_MAN_PATH));
 138                         exit(0);
 139                 } else if (!strcmp(cmd, "--info-path")) {
 140                         puts(system_path(GIT_INFO_PATH));
 141                         exit(0);
 142                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 143                         use_pager = 1;
 144                 } else if (!strcmp(cmd, "--no-pager")) {
 145                         use_pager = 0;
 146                         if (envchanged)
 147                                 *envchanged = 1;
 148                 } else if (!strcmp(cmd, "--no-replace-objects")) {
 149                         check_replace_refs = 0;
 150                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 151                         if (envchanged)
 152                                 *envchanged = 1;
 153                 } else if (!strcmp(cmd, "--git-dir")) {
 154                         if (*argc < 2) {
 155                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
 156                                 usage(git_usage_string);
 157                         }
 158                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 159                         if (envchanged)
 160                                 *envchanged = 1;
 161                         (*argv)++;
 162                         (*argc)--;
 163                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 164                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 165                         if (envchanged)
 166                                 *envchanged = 1;
 167                 } else if (!strcmp(cmd, "--namespace")) {
 168                         if (*argc < 2) {
 169                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 170                                 usage(git_usage_string);
 171                         }
 172                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 173                         if (envchanged)
 174                                 *envchanged = 1;
 175                         (*argv)++;
 176                         (*argc)--;
 177                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 178                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 179                         if (envchanged)
 180                                 *envchanged = 1;
 181                 } else if (!strcmp(cmd, "--work-tree")) {
 182                         if (*argc < 2) {
 183                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
 184                                 usage(git_usage_string);
 185                         }
 186                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 187                         if (envchanged)
 188                                 *envchanged = 1;
 189                         (*argv)++;
 190                         (*argc)--;
 191                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 192                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 193                         if (envchanged)
 194                                 *envchanged = 1;
 195                 } else if (!strcmp(cmd, "--super-prefix")) {
 196                         if (*argc < 2) {
 197                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 198                                 usage(git_usage_string);
 199                         }
 200                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 201                         if (envchanged)
 202                                 *envchanged = 1;
 203                         (*argv)++;
 204                         (*argc)--;
 205                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 206                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 207                         if (envchanged)
 208                                 *envchanged = 1;
 209                 } else if (!strcmp(cmd, "--bare")) {
 210                         char *cwd = xgetcwd();
 211                         is_bare_repository_cfg = 1;
 212                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 213                         free(cwd);
 214                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 215                         if (envchanged)
 216                                 *envchanged = 1;
 217                 } else if (!strcmp(cmd, "-c")) {
 218                         if (*argc < 2) {
 219                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 220                                 usage(git_usage_string);
 221                         }
 222                         git_config_push_parameter((*argv)[1]);
 223                         (*argv)++;
 224                         (*argc)--;
 225                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 226                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 227                         if (envchanged)
 228                                 *envchanged = 1;
 229                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 230                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 231                         if (envchanged)
 232                                 *envchanged = 1;
 233                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 234                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 235                         if (envchanged)
 236                                 *envchanged = 1;
 237                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 238                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 239                         if (envchanged)
 240                                 *envchanged = 1;
 241                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 242                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 243                         if (envchanged)
 244                                 *envchanged = 1;
 245                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 246                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 247                         if (envchanged)
 248                                 *envchanged = 1;
 249                 } else if (!strcmp(cmd, "--shallow-file")) {
 250                         (*argv)++;
 251                         (*argc)--;
 252                         set_alternate_shallow_file((*argv)[0], 1);
 253                         if (envchanged)
 254                                 *envchanged = 1;
 255                 } else if (!strcmp(cmd, "-C")) {
 256                         if (*argc < 2) {
 257                                 fprintf(stderr, _("no directory given for -C\n" ));
 258                                 usage(git_usage_string);
 259                         }
 260                         if ((*argv)[1][0]) {
 261                                 if (chdir((*argv)[1]))
 262                                         die_errno("cannot change to '%s'", (*argv)[1]);
 263                                 if (envchanged)
 264                                         *envchanged = 1;
 265                         }
 266                         (*argv)++;
 267                         (*argc)--;
 268                 } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
 269                         if (!strcmp(cmd, "parseopt")) {
 270                                 struct string_list list = STRING_LIST_INIT_DUP;
 271                                 int i;
 272
 273                                 list_builtins(&list, NO_PARSEOPT);
 274                                 for (i = 0; i < list.nr; i++)
 275                                         printf("%s ", list.items[i].string);
 276                                 string_list_clear(&list, 0);
 277                                 exit(0);
 278                         } else {
 279                                 exit(list_cmds(cmd));
 280                         }
 281                 } else {
 282                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 283                         usage(git_usage_string);
 284                 }
 285
 286                 (*argv)++;
 287                 (*argc)--;
 288         }
 289         return (*argv) - orig_argv;
 290 }
 291
 292 static int handle_alias(int *argcp, const char ***argv)
 293 {
 294         int envchanged = 0, ret = 0, saved_errno = errno;
 295         int count, option_count;
 296         const char **new_argv;
 297         const char *alias_command;
 298         char *alias_string;
 299
 300         alias_command = (*argv)[0];
 301         alias_string = alias_lookup(alias_command);
 302         if (alias_string) {
 303                 if (alias_string[0] == '!') {
 304                         struct child_process child = CHILD_PROCESS_INIT;
 305                         int nongit_ok;
 306
 307                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 308                         setup_git_directory_gently(&nongit_ok);
 309
 310                         commit_pager_choice();
 311
 312                         child.use_shell = 1;
 313                         argv_array_push(&child.args, alias_string + 1);
 314                         argv_array_pushv(&child.args, (*argv) + 1);
 315
 316                         ret = run_command(&child);
 317                         if (ret >= 0)   /* normal exit */
 318                                 exit(ret);
 319
 320                         die_errno("while expanding alias '%s': '%s'",
 321                             alias_command, alias_string + 1);
 322                 }
 323                 count = split_cmdline(alias_string, &new_argv);
 324                 if (count < 0)
 325                         die("Bad alias.%s string: %s", alias_command,
 326                             split_cmdline_strerror(count));
 327                 option_count = handle_options(&new_argv, &count, &envchanged);
 328                 if (envchanged)
 329                         die("alias '%s' changes environment variables.\n"
 330                                  "You can use '!git' in the alias to do this",
 331                                  alias_command);
 332                 memmove(new_argv - option_count, new_argv,
 333                                 count * sizeof(char *));
 334                 new_argv -= option_count;
 335
 336                 if (count < 1)
 337                         die("empty alias for %s", alias_command);
 338
 339                 if (!strcmp(alias_command, new_argv[0]))
 340                         die("recursive alias: %s", alias_command);
 341
 342                 trace_argv_printf(new_argv,
 343                                   "trace: alias expansion: %s =>",
 344                                   alias_command);
 345
 346                 REALLOC_ARRAY(new_argv, count + *argcp);
 347                 /* insert after command name */
 348                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 349
 350                 *argv = new_argv;
 351                 *argcp += count - 1;
 352
 353                 ret = 1;
 354         }
 355
 356         errno = saved_errno;
 357
 358         return ret;
 359 }
 360
 361 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 362 {
 363         int status, help;
 364         struct stat st;
 365         const char *prefix;
 366
 367         prefix = NULL;
 368         help = argc == 2 && !strcmp(argv[1], "-h");
 369         if (!help) {
 370                 if (p->option & RUN_SETUP)
 371                         prefix = setup_git_directory();
 372                 else if (p->option & RUN_SETUP_GENTLY) {
 373                         int nongit_ok;
 374                         prefix = setup_git_directory_gently(&nongit_ok);
 375                 }
 376
 377                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 378                     !(p->option & DELAY_PAGER_CONFIG))
 379                         use_pager = check_pager_config(p->cmd);
 380                 if (use_pager == -1 && p->option & USE_PAGER)
 381                         use_pager = 1;
 382
 383                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 384                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 385                         trace_repo_setup(prefix);
 386         }
 387         commit_pager_choice();
 388
 389         if (!help && get_super_prefix()) {
 390                 if (!(p->option & SUPPORT_SUPER_PREFIX))
 391                         die("%s doesn't support --super-prefix", p->cmd);
 392         }
 393
 394         if (!help && p->option & NEED_WORK_TREE)
 395                 setup_work_tree();
 396
 397         trace_argv_printf(argv, "trace: built-in: git");
 398
 399         status = p->fn(argc, argv, prefix);
 400         if (status)
 401                 return status;
 402
 403         /* Somebody closed stdout? */
 404         if (fstat(fileno(stdout), &st))
 405                 return 0;
 406         /* Ignore write errors for pipes and sockets.. */
 407         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 408                 return 0;
 409
 410         /* Check for ENOSPC and EIO errors.. */
 411         if (fflush(stdout))
 412                 die_errno("write failure on standard output");
 413         if (ferror(stdout))
 414                 die("unknown write failure on standard output");
 415         if (fclose(stdout))
 416                 die_errno("close failed on standard output");
 417         return 0;
 418 }
 419
 420 static struct cmd_struct commands[] = {
 421         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 422         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 423         { "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
 424         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 425         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 426         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 427         { "blame", cmd_blame, RUN_SETUP },
 428         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 429         { "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
 430         { "cat-file", cmd_cat_file, RUN_SETUP },
 431         { "check-attr", cmd_check_attr, RUN_SETUP },
 432         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 433         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 434         { "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
 435         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 436         { "checkout-index", cmd_checkout_index,
 437                 RUN_SETUP | NEED_WORK_TREE},
 438         { "cherry", cmd_cherry, RUN_SETUP },
 439         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 440         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 441         { "clone", cmd_clone },
 442         { "column", cmd_column, RUN_SETUP_GENTLY },
 443         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 444         { "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
 445         { "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
 446         { "count-objects", cmd_count_objects, RUN_SETUP },
 447         { "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
 448         { "describe", cmd_describe, RUN_SETUP },
 449         { "diff", cmd_diff, NO_PARSEOPT },
 450         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 451         { "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 452         { "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
 453         { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 454         { "fast-export", cmd_fast_export, RUN_SETUP },
 455         { "fetch", cmd_fetch, RUN_SETUP },
 456         { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
 457         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 458         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 459         { "format-patch", cmd_format_patch, RUN_SETUP },
 460         { "fsck", cmd_fsck, RUN_SETUP },
 461         { "fsck-objects", cmd_fsck, RUN_SETUP },
 462         { "gc", cmd_gc, RUN_SETUP },
 463         { "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
 464         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 465         { "hash-object", cmd_hash_object },
 466         { "help", cmd_help },
 467         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 468         { "init", cmd_init_db },
 469         { "init-db", cmd_init_db },
 470         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 471         { "log", cmd_log, RUN_SETUP },
 472         { "ls-files", cmd_ls_files, RUN_SETUP },
 473         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 474         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 475         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
 476         { "mailsplit", cmd_mailsplit, NO_PARSEOPT },
 477         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 478         { "merge-base", cmd_merge_base, RUN_SETUP },
 479         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 480         { "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
 481         { "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
 482         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 483         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 484         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 485         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 486         { "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 487         { "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 488         { "mktree", cmd_mktree, RUN_SETUP },
 489         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 490         { "name-rev", cmd_name_rev, RUN_SETUP },
 491         { "notes", cmd_notes, RUN_SETUP },
 492         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 493         { "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
 494         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 495         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
 496         { "pickaxe", cmd_blame, RUN_SETUP },
 497         { "prune", cmd_prune, RUN_SETUP },
 498         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 499         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 500         { "push", cmd_push, RUN_SETUP },
 501         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 502         { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 503         { "receive-pack", cmd_receive_pack },
 504         { "reflog", cmd_reflog, RUN_SETUP },
 505         { "remote", cmd_remote, RUN_SETUP },
 506         { "remote-ext", cmd_remote_ext, NO_PARSEOPT },
 507         { "remote-fd", cmd_remote_fd, NO_PARSEOPT },
 508         { "repack", cmd_repack, RUN_SETUP },
 509         { "replace", cmd_replace, RUN_SETUP },
 510         { "rerere", cmd_rerere, RUN_SETUP },
 511         { "reset", cmd_reset, RUN_SETUP },
 512         { "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 513         { "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 514         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 515         { "rm", cmd_rm, RUN_SETUP },
 516         { "send-pack", cmd_send_pack, RUN_SETUP },
 517         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 518         { "show", cmd_show, RUN_SETUP },
 519         { "show-branch", cmd_show_branch, RUN_SETUP },
 520         { "show-ref", cmd_show_ref, RUN_SETUP },
 521         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 522         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 523         { "stripspace", cmd_stripspace },
 524         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
 525         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 526         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 527         { "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
 528         { "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
 529         { "update-index", cmd_update_index, RUN_SETUP },
 530         { "update-ref", cmd_update_ref, RUN_SETUP },
 531         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 532         { "upload-archive", cmd_upload_archive, NO_PARSEOPT },
 533         { "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
 534         { "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
 535         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 536         { "verify-pack", cmd_verify_pack },
 537         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 538         { "version", cmd_version },
 539         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 540         { "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
 541         { "write-tree", cmd_write_tree, RUN_SETUP },
 542 };
 543
 544 static struct cmd_struct *get_builtin(const char *s)
 545 {
 546         int i;
 547         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 548                 struct cmd_struct *p = commands + i;
 549                 if (!strcmp(s, p->cmd))
 550                         return p;
 551         }
 552         return NULL;
 553 }
 554
 555 int is_builtin(const char *s)
 556 {
 557         return !!get_builtin(s);
 558 }
 559
 560 static void list_builtins(struct string_list *out, unsigned int exclude_option)
 561 {
 562         int i;
 563         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 564                 if (exclude_option &&
 565                     (commands[i].option & exclude_option))
 566                         continue;
 567                 string_list_append(out, commands[i].cmd);
 568         }
 569 }
 570
 571 #ifdef STRIP_EXTENSION
 572 static void strip_extension(const char **argv)
 573 {
 574         size_t len;
 575
 576         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 577                 argv[0] = xmemdupz(argv[0], len);
 578 }
 579 #else
 580 #define strip_extension(cmd)
 581 #endif
 582
 583 static void handle_builtin(int argc, const char **argv)
 584 {
 585         struct argv_array args = ARGV_ARRAY_INIT;
 586         const char *cmd;
 587         struct cmd_struct *builtin;
 588
 589         strip_extension(argv);
 590         cmd = argv[0];
 591
 592         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 593         if (argc > 1 && !strcmp(argv[1], "--help")) {
 594                 int i;
 595
 596                 argv[1] = argv[0];
 597                 argv[0] = cmd = "help";
 598
 599                 for (i = 0; i < argc; i++) {
 600                         argv_array_push(&args, argv[i]);
 601                         if (!i)
 602                                 argv_array_push(&args, "--exclude-guides");
 603                 }
 604
 605                 argc++;
 606                 argv = args.argv;
 607         }
 608
 609         builtin = get_builtin(cmd);
 610         if (builtin)
 611                 exit(run_builtin(builtin, argc, argv));
 612         argv_array_clear(&args);
 613 }
 614
 615 static void execv_dashed_external(const char **argv)
 616 {
 617         struct child_process cmd = CHILD_PROCESS_INIT;
 618         int status;
 619
 620         if (get_super_prefix())
 621                 die("%s doesn't support --super-prefix", argv[0]);
 622
 623         if (use_pager == -1 && !is_builtin(argv[0]))
 624                 use_pager = check_pager_config(argv[0]);
 625         commit_pager_choice();
 626
 627         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 628         argv_array_pushv(&cmd.args, argv + 1);
 629         cmd.clean_on_exit = 1;
 630         cmd.wait_after_clean = 1;
 631         cmd.silent_exec_failure = 1;
 632
 633         trace_argv_printf(cmd.args.argv, "trace: exec:");
 634
 635         /*
 636          * If we fail because the command is not found, it is
 637          * OK to return. Otherwise, we just pass along the status code,
 638          * or our usual generic code if we were not even able to exec
 639          * the program.
 640          */
 641         status = run_command(&cmd);
 642         if (status >= 0)
 643                 exit(status);
 644         else if (errno != ENOENT)
 645                 exit(128);
 646 }
 647
 648 static int run_argv(int *argcp, const char ***argv)
 649 {
 650         int done_alias = 0;
 651
 652         while (1) {
 653                 /*
 654                  * If we tried alias and futzed with our environment,
 655                  * it no longer is safe to invoke builtins directly in
 656                  * general.  We have to spawn them as dashed externals.
 657                  *
 658                  * NEEDSWORK: if we can figure out cases
 659                  * where it is safe to do, we can avoid spawning a new
 660                  * process.
 661                  */
 662                 if (!done_alias)
 663                         handle_builtin(*argcp, *argv);
 664
 665                 /* .. then try the external ones */
 666                 execv_dashed_external(*argv);
 667
 668                 /* It could be an alias -- this works around the insanity
 669                  * of overriding "git log" with "git show" by having
 670                  * alias.log = show
 671                  */
 672                 if (done_alias)
 673                         break;
 674                 if (!handle_alias(argcp, argv))
 675                         break;
 676                 done_alias = 1;
 677         }
 678
 679         return done_alias;
 680 }
 681
 682 int cmd_main(int argc, const char **argv)
 683 {
 684         const char *cmd;
 685         int done_help = 0;
 686
 687         cmd = argv[0];
 688         if (!cmd)
 689                 cmd = "git-help";
 690         else {
 691                 const char *slash = find_last_dir_sep(cmd);
 692                 if (slash)
 693                         cmd = slash + 1;
 694         }
 695
 696         trace_command_performance(argv);
 697
 698         /*
 699          * "git-xxxx" is the same as "git xxxx", but we obviously:
 700          *
 701          *  - cannot take flags in between the "git" and the "xxxx".
 702          *  - cannot execute it externally (since it would just do
 703          *    the same thing over again)
 704          *
 705          * So we just directly call the builtin handler, and die if
 706          * that one cannot handle it.
 707          */
 708         if (skip_prefix(cmd, "git-", &cmd)) {
 709                 argv[0] = cmd;
 710                 handle_builtin(argc, argv);
 711                 die("cannot handle %s as a builtin", cmd);
 712         }
 713
 714         /* Look for flags.. */
 715         argv++;
 716         argc--;
 717         handle_options(&argv, &argc, NULL);
 718         if (argc > 0) {
 719                 /* translate --help and --version into commands */
 720                 skip_prefix(argv[0], "--", &argv[0]);
 721         } else {
 722                 /* The user didn't specify a command; give them help */
 723                 commit_pager_choice();
 724                 printf("usage: %s\n\n", git_usage_string);
 725                 list_common_cmds_help();
 726                 printf("\n%s\n", _(git_more_info_string));
 727                 exit(1);
 728         }
 729         cmd = argv[0];
 730
 731         /*
 732          * We use PATH to find git commands, but we prepend some higher
 733          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 734          * environment, and the $(gitexecdir) from the Makefile at build
 735          * time.
 736          */
 737         setup_path();
 738
 739         while (1) {
 740                 int was_alias = run_argv(&argc, &argv);
 741                 if (errno != ENOENT)
 742                         break;
 743                 if (was_alias) {
 744                         fprintf(stderr, _("expansion of alias '%s' failed; "
 745                                           "'%s' is not a git command\n"),
 746                                 cmd, argv[0]);
 747                         exit(1);
 748                 }
 749                 if (!done_help) {
 750                         cmd = argv[0] = help_unknown_cmd(cmd);
 751                         done_help = 1;
 752                 } else
 753                         break;
 754         }
 755
 756         fprintf(stderr, _("failed to run command '%s': %s\n"),
 757                 cmd, strerror(errno));
 758
 759         return 1;
 760 }