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