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