Andrew's git / gitweb.git / git.c
?
git.con commit command-list.txt: documentation and guide line (fe902f2)
   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
  19struct cmd_struct {
  20        const char *cmd;
  21        int (*fn)(int, const char **, const char *);
  22        unsigned int option;
  23};
  24
  25const 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
  32const 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
  37static int use_pager = -1;
  38
  39static void list_builtins(struct string_list *list, unsigned int exclude_option);
  40
  41static 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
  48static 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
  82static 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
  95void 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
 105static 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
 291static 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
 360static 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
 419static 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
 543static 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
 554int is_builtin(const char *s)
 555{
 556        return !!get_builtin(s);
 557}
 558
 559static 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
 571static 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
 582static 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
 614static 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
 647static 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
 681int 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}