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