git.con commit fetch-pack: refactor parsing in get_ack (82e5676)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "exec_cmd.h"
   4#include "help.h"
   5#include "quote.h"
   6#include "run-command.h"
   7#include "commit.h"
   8
   9const char git_usage_string[] =
  10        "git [--version] [--help] [-C <path>] [-c name=value]\n"
  11        "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  12        "           [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]\n"
  13        "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  14        "           <command> [<args>]";
  15
  16const char git_more_info_string[] =
  17        N_("'git help -a' and 'git help -g' lists available subcommands and some\n"
  18           "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  19           "to read about a specific subcommand or concept.");
  20
  21static struct startup_info git_startup_info;
  22static int use_pager = -1;
  23
  24static void commit_pager_choice(void) {
  25        switch (use_pager) {
  26        case 0:
  27                setenv("GIT_PAGER", "cat", 1);
  28                break;
  29        case 1:
  30                setup_pager();
  31                break;
  32        default:
  33                break;
  34        }
  35}
  36
  37static int handle_options(const char ***argv, int *argc, int *envchanged)
  38{
  39        const char **orig_argv = *argv;
  40
  41        while (*argc > 0) {
  42                const char *cmd = (*argv)[0];
  43                if (cmd[0] != '-')
  44                        break;
  45
  46                /*
  47                 * For legacy reasons, the "version" and "help"
  48                 * commands can be written with "--" prepended
  49                 * to make them look like flags.
  50                 */
  51                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  52                        break;
  53
  54                /*
  55                 * Check remaining flags.
  56                 */
  57                if (skip_prefix(cmd, "--exec-path", &cmd)) {
  58                        if (*cmd == '=')
  59                                git_set_argv_exec_path(cmd + 1);
  60                        else {
  61                                puts(git_exec_path());
  62                                exit(0);
  63                        }
  64                } else if (!strcmp(cmd, "--html-path")) {
  65                        puts(system_path(GIT_HTML_PATH));
  66                        exit(0);
  67                } else if (!strcmp(cmd, "--man-path")) {
  68                        puts(system_path(GIT_MAN_PATH));
  69                        exit(0);
  70                } else if (!strcmp(cmd, "--info-path")) {
  71                        puts(system_path(GIT_INFO_PATH));
  72                        exit(0);
  73                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  74                        use_pager = 1;
  75                } else if (!strcmp(cmd, "--no-pager")) {
  76                        use_pager = 0;
  77                        if (envchanged)
  78                                *envchanged = 1;
  79                } else if (!strcmp(cmd, "--no-replace-objects")) {
  80                        check_replace_refs = 0;
  81                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  82                        if (envchanged)
  83                                *envchanged = 1;
  84                } else if (!strcmp(cmd, "--git-dir")) {
  85                        if (*argc < 2) {
  86                                fprintf(stderr, "No directory given for --git-dir.\n" );
  87                                usage(git_usage_string);
  88                        }
  89                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
  90                        if (envchanged)
  91                                *envchanged = 1;
  92                        (*argv)++;
  93                        (*argc)--;
  94                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
  95                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
  96                        if (envchanged)
  97                                *envchanged = 1;
  98                } else if (!strcmp(cmd, "--namespace")) {
  99                        if (*argc < 2) {
 100                                fprintf(stderr, "No namespace given for --namespace.\n" );
 101                                usage(git_usage_string);
 102                        }
 103                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 104                        if (envchanged)
 105                                *envchanged = 1;
 106                        (*argv)++;
 107                        (*argc)--;
 108                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 109                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 110                        if (envchanged)
 111                                *envchanged = 1;
 112                } else if (!strcmp(cmd, "--work-tree")) {
 113                        if (*argc < 2) {
 114                                fprintf(stderr, "No directory given for --work-tree.\n" );
 115                                usage(git_usage_string);
 116                        }
 117                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 118                        if (envchanged)
 119                                *envchanged = 1;
 120                        (*argv)++;
 121                        (*argc)--;
 122                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 123                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 124                        if (envchanged)
 125                                *envchanged = 1;
 126                } else if (!strcmp(cmd, "--bare")) {
 127                        static char git_dir[PATH_MAX+1];
 128                        is_bare_repository_cfg = 1;
 129                        setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 130                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 131                        if (envchanged)
 132                                *envchanged = 1;
 133                } else if (!strcmp(cmd, "-c")) {
 134                        if (*argc < 2) {
 135                                fprintf(stderr, "-c expects a configuration string\n" );
 136                                usage(git_usage_string);
 137                        }
 138                        git_config_push_parameter((*argv)[1]);
 139                        (*argv)++;
 140                        (*argc)--;
 141                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 142                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 143                        if (envchanged)
 144                                *envchanged = 1;
 145                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 146                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 147                        if (envchanged)
 148                                *envchanged = 1;
 149                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 150                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 151                        if (envchanged)
 152                                *envchanged = 1;
 153                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 154                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 155                        if (envchanged)
 156                                *envchanged = 1;
 157                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 158                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 159                        if (envchanged)
 160                                *envchanged = 1;
 161                } else if (!strcmp(cmd, "--shallow-file")) {
 162                        (*argv)++;
 163                        (*argc)--;
 164                        set_alternate_shallow_file((*argv)[0], 1);
 165                        if (envchanged)
 166                                *envchanged = 1;
 167                } else if (!strcmp(cmd, "-C")) {
 168                        if (*argc < 2) {
 169                                fprintf(stderr, "No directory given for -C.\n" );
 170                                usage(git_usage_string);
 171                        }
 172                        if (chdir((*argv)[1]))
 173                                die_errno("Cannot change to '%s'", (*argv)[1]);
 174                        if (envchanged)
 175                                *envchanged = 1;
 176                        (*argv)++;
 177                        (*argc)--;
 178                } else {
 179                        fprintf(stderr, "Unknown option: %s\n", cmd);
 180                        usage(git_usage_string);
 181                }
 182
 183                (*argv)++;
 184                (*argc)--;
 185        }
 186        return (*argv) - orig_argv;
 187}
 188
 189static int handle_alias(int *argcp, const char ***argv)
 190{
 191        int envchanged = 0, ret = 0, saved_errno = errno;
 192        const char *subdir;
 193        int count, option_count;
 194        const char **new_argv;
 195        const char *alias_command;
 196        char *alias_string;
 197        int unused_nongit;
 198
 199        subdir = setup_git_directory_gently(&unused_nongit);
 200
 201        alias_command = (*argv)[0];
 202        alias_string = alias_lookup(alias_command);
 203        if (alias_string) {
 204                if (alias_string[0] == '!') {
 205                        const char **alias_argv;
 206                        int argc = *argcp, i;
 207
 208                        commit_pager_choice();
 209
 210                        /* build alias_argv */
 211                        alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 1));
 212                        alias_argv[0] = alias_string + 1;
 213                        for (i = 1; i < argc; ++i)
 214                                alias_argv[i] = (*argv)[i];
 215                        alias_argv[argc] = NULL;
 216
 217                        ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
 218                        if (ret >= 0)   /* normal exit */
 219                                exit(ret);
 220
 221                        die_errno("While expanding alias '%s': '%s'",
 222                            alias_command, alias_string + 1);
 223                }
 224                count = split_cmdline(alias_string, &new_argv);
 225                if (count < 0)
 226                        die("Bad alias.%s string: %s", alias_command,
 227                            split_cmdline_strerror(count));
 228                option_count = handle_options(&new_argv, &count, &envchanged);
 229                if (envchanged)
 230                        die("alias '%s' changes environment variables\n"
 231                                 "You can use '!git' in the alias to do this.",
 232                                 alias_command);
 233                memmove(new_argv - option_count, new_argv,
 234                                count * sizeof(char *));
 235                new_argv -= option_count;
 236
 237                if (count < 1)
 238                        die("empty alias for %s", alias_command);
 239
 240                if (!strcmp(alias_command, new_argv[0]))
 241                        die("recursive alias: %s", alias_command);
 242
 243                trace_argv_printf(new_argv,
 244                                  "trace: alias expansion: %s =>",
 245                                  alias_command);
 246
 247                new_argv = xrealloc(new_argv, sizeof(char *) *
 248                                    (count + *argcp));
 249                /* insert after command name */
 250                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 251
 252                *argv = new_argv;
 253                *argcp += count - 1;
 254
 255                ret = 1;
 256        }
 257
 258        if (subdir && chdir(subdir))
 259                die_errno("Cannot change to '%s'", subdir);
 260
 261        errno = saved_errno;
 262
 263        return ret;
 264}
 265
 266#define RUN_SETUP               (1<<0)
 267#define RUN_SETUP_GENTLY        (1<<1)
 268#define USE_PAGER               (1<<2)
 269/*
 270 * require working tree to be present -- anything uses this needs
 271 * RUN_SETUP for reading from the configuration file.
 272 */
 273#define NEED_WORK_TREE          (1<<3)
 274
 275struct cmd_struct {
 276        const char *cmd;
 277        int (*fn)(int, const char **, const char *);
 278        int option;
 279};
 280
 281static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 282{
 283        int status, help;
 284        struct stat st;
 285        const char *prefix;
 286
 287        prefix = NULL;
 288        help = argc == 2 && !strcmp(argv[1], "-h");
 289        if (!help) {
 290                if (p->option & RUN_SETUP)
 291                        prefix = setup_git_directory();
 292                else if (p->option & RUN_SETUP_GENTLY) {
 293                        int nongit_ok;
 294                        prefix = setup_git_directory_gently(&nongit_ok);
 295                }
 296
 297                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
 298                        use_pager = check_pager_config(p->cmd);
 299                if (use_pager == -1 && p->option & USE_PAGER)
 300                        use_pager = 1;
 301
 302                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 303                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 304                        trace_repo_setup(prefix);
 305        }
 306        commit_pager_choice();
 307
 308        if (!help && p->option & NEED_WORK_TREE)
 309                setup_work_tree();
 310
 311        trace_argv_printf(argv, "trace: built-in: git");
 312
 313        status = p->fn(argc, argv, prefix);
 314        if (status)
 315                return status;
 316
 317        /* Somebody closed stdout? */
 318        if (fstat(fileno(stdout), &st))
 319                return 0;
 320        /* Ignore write errors for pipes and sockets.. */
 321        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 322                return 0;
 323
 324        /* Check for ENOSPC and EIO errors.. */
 325        if (fflush(stdout))
 326                die_errno("write failure on standard output");
 327        if (ferror(stdout))
 328                die("unknown write failure on standard output");
 329        if (fclose(stdout))
 330                die_errno("close failed on standard output");
 331        return 0;
 332}
 333
 334static struct cmd_struct commands[] = {
 335        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 336        { "annotate", cmd_annotate, RUN_SETUP },
 337        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 338        { "archive", cmd_archive },
 339        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 340        { "blame", cmd_blame, RUN_SETUP },
 341        { "branch", cmd_branch, RUN_SETUP },
 342        { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 343        { "cat-file", cmd_cat_file, RUN_SETUP },
 344        { "check-attr", cmd_check_attr, RUN_SETUP },
 345        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 346        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 347        { "check-ref-format", cmd_check_ref_format },
 348        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 349        { "checkout-index", cmd_checkout_index,
 350                RUN_SETUP | NEED_WORK_TREE},
 351        { "cherry", cmd_cherry, RUN_SETUP },
 352        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 353        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 354        { "clone", cmd_clone },
 355        { "column", cmd_column, RUN_SETUP_GENTLY },
 356        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 357        { "commit-tree", cmd_commit_tree, RUN_SETUP },
 358        { "config", cmd_config, RUN_SETUP_GENTLY },
 359        { "count-objects", cmd_count_objects, RUN_SETUP },
 360        { "credential", cmd_credential, RUN_SETUP_GENTLY },
 361        { "describe", cmd_describe, RUN_SETUP },
 362        { "diff", cmd_diff },
 363        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 364        { "diff-index", cmd_diff_index, RUN_SETUP },
 365        { "diff-tree", cmd_diff_tree, RUN_SETUP },
 366        { "fast-export", cmd_fast_export, RUN_SETUP },
 367        { "fetch", cmd_fetch, RUN_SETUP },
 368        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 369        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 370        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 371        { "format-patch", cmd_format_patch, RUN_SETUP },
 372        { "fsck", cmd_fsck, RUN_SETUP },
 373        { "fsck-objects", cmd_fsck, RUN_SETUP },
 374        { "gc", cmd_gc, RUN_SETUP },
 375        { "get-tar-commit-id", cmd_get_tar_commit_id },
 376        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 377        { "hash-object", cmd_hash_object },
 378        { "help", cmd_help },
 379        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 380        { "init", cmd_init_db },
 381        { "init-db", cmd_init_db },
 382        { "log", cmd_log, RUN_SETUP },
 383        { "ls-files", cmd_ls_files, RUN_SETUP },
 384        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 385        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 386        { "mailinfo", cmd_mailinfo },
 387        { "mailsplit", cmd_mailsplit },
 388        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 389        { "merge-base", cmd_merge_base, RUN_SETUP },
 390        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 391        { "merge-index", cmd_merge_index, RUN_SETUP },
 392        { "merge-ours", cmd_merge_ours, RUN_SETUP },
 393        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 394        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 395        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 396        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 397        { "merge-tree", cmd_merge_tree, RUN_SETUP },
 398        { "mktag", cmd_mktag, RUN_SETUP },
 399        { "mktree", cmd_mktree, RUN_SETUP },
 400        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 401        { "name-rev", cmd_name_rev, RUN_SETUP },
 402        { "notes", cmd_notes, RUN_SETUP },
 403        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 404        { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 405        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 406        { "patch-id", cmd_patch_id },
 407        { "pickaxe", cmd_blame, RUN_SETUP },
 408        { "prune", cmd_prune, RUN_SETUP },
 409        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 410        { "push", cmd_push, RUN_SETUP },
 411        { "read-tree", cmd_read_tree, RUN_SETUP },
 412        { "receive-pack", cmd_receive_pack },
 413        { "reflog", cmd_reflog, RUN_SETUP },
 414        { "remote", cmd_remote, RUN_SETUP },
 415        { "remote-ext", cmd_remote_ext },
 416        { "remote-fd", cmd_remote_fd },
 417        { "repack", cmd_repack, RUN_SETUP },
 418        { "replace", cmd_replace, RUN_SETUP },
 419        { "rerere", cmd_rerere, RUN_SETUP },
 420        { "reset", cmd_reset, RUN_SETUP },
 421        { "rev-list", cmd_rev_list, RUN_SETUP },
 422        { "rev-parse", cmd_rev_parse },
 423        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 424        { "rm", cmd_rm, RUN_SETUP },
 425        { "send-pack", cmd_send_pack, RUN_SETUP },
 426        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 427        { "show", cmd_show, RUN_SETUP },
 428        { "show-branch", cmd_show_branch, RUN_SETUP },
 429        { "show-ref", cmd_show_ref, RUN_SETUP },
 430        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 431        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 432        { "stripspace", cmd_stripspace },
 433        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 434        { "tag", cmd_tag, RUN_SETUP },
 435        { "unpack-file", cmd_unpack_file, RUN_SETUP },
 436        { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 437        { "update-index", cmd_update_index, RUN_SETUP },
 438        { "update-ref", cmd_update_ref, RUN_SETUP },
 439        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 440        { "upload-archive", cmd_upload_archive },
 441        { "upload-archive--writer", cmd_upload_archive_writer },
 442        { "var", cmd_var, RUN_SETUP_GENTLY },
 443        { "verify-pack", cmd_verify_pack },
 444        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 445        { "version", cmd_version },
 446        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 447        { "write-tree", cmd_write_tree, RUN_SETUP },
 448};
 449
 450int is_builtin(const char *s)
 451{
 452        int i;
 453        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 454                struct cmd_struct *p = commands+i;
 455                if (!strcmp(s, p->cmd))
 456                        return 1;
 457        }
 458        return 0;
 459}
 460
 461static void handle_builtin(int argc, const char **argv)
 462{
 463        const char *cmd = argv[0];
 464        int i;
 465        static const char ext[] = STRIP_EXTENSION;
 466
 467        if (sizeof(ext) > 1) {
 468                i = strlen(argv[0]) - strlen(ext);
 469                if (i > 0 && !strcmp(argv[0] + i, ext)) {
 470                        char *argv0 = xstrdup(argv[0]);
 471                        argv[0] = cmd = argv0;
 472                        argv0[i] = '\0';
 473                }
 474        }
 475
 476        /* Turn "git cmd --help" into "git help cmd" */
 477        if (argc > 1 && !strcmp(argv[1], "--help")) {
 478                argv[1] = argv[0];
 479                argv[0] = cmd = "help";
 480        }
 481
 482        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 483                struct cmd_struct *p = commands+i;
 484                if (strcmp(p->cmd, cmd))
 485                        continue;
 486                exit(run_builtin(p, argc, argv));
 487        }
 488}
 489
 490static void execv_dashed_external(const char **argv)
 491{
 492        struct strbuf cmd = STRBUF_INIT;
 493        const char *tmp;
 494        int status;
 495
 496        if (use_pager == -1)
 497                use_pager = check_pager_config(argv[0]);
 498        commit_pager_choice();
 499
 500        strbuf_addf(&cmd, "git-%s", argv[0]);
 501
 502        /*
 503         * argv[0] must be the git command, but the argv array
 504         * belongs to the caller, and may be reused in
 505         * subsequent loop iterations. Save argv[0] and
 506         * restore it on error.
 507         */
 508        tmp = argv[0];
 509        argv[0] = cmd.buf;
 510
 511        trace_argv_printf(argv, "trace: exec:");
 512
 513        /*
 514         * if we fail because the command is not found, it is
 515         * OK to return. Otherwise, we just pass along the status code.
 516         */
 517        status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
 518        if (status >= 0 || errno != ENOENT)
 519                exit(status);
 520
 521        argv[0] = tmp;
 522
 523        strbuf_release(&cmd);
 524}
 525
 526static int run_argv(int *argcp, const char ***argv)
 527{
 528        int done_alias = 0;
 529
 530        while (1) {
 531                /* See if it's a builtin */
 532                handle_builtin(*argcp, *argv);
 533
 534                /* .. then try the external ones */
 535                execv_dashed_external(*argv);
 536
 537                /* It could be an alias -- this works around the insanity
 538                 * of overriding "git log" with "git show" by having
 539                 * alias.log = show
 540                 */
 541                if (done_alias || !handle_alias(argcp, argv))
 542                        break;
 543                done_alias = 1;
 544        }
 545
 546        return done_alias;
 547}
 548
 549
 550int main(int argc, char **av)
 551{
 552        const char **argv = (const char **) av;
 553        const char *cmd;
 554
 555        startup_info = &git_startup_info;
 556
 557        cmd = git_extract_argv0_path(argv[0]);
 558        if (!cmd)
 559                cmd = "git-help";
 560
 561        /*
 562         * Always open file descriptors 0/1/2 to avoid clobbering files
 563         * in die().  It also avoids messing up when the pipes are dup'ed
 564         * onto stdin/stdout/stderr in the child processes we spawn.
 565         */
 566        sanitize_stdfds();
 567
 568        git_setup_gettext();
 569
 570        /*
 571         * "git-xxxx" is the same as "git xxxx", but we obviously:
 572         *
 573         *  - cannot take flags in between the "git" and the "xxxx".
 574         *  - cannot execute it externally (since it would just do
 575         *    the same thing over again)
 576         *
 577         * So we just directly call the builtin handler, and die if
 578         * that one cannot handle it.
 579         */
 580        if (skip_prefix(cmd, "git-", &cmd)) {
 581                argv[0] = cmd;
 582                handle_builtin(argc, argv);
 583                die("cannot handle %s as a builtin", cmd);
 584        }
 585
 586        /* Look for flags.. */
 587        argv++;
 588        argc--;
 589        handle_options(&argv, &argc, NULL);
 590        if (argc > 0) {
 591                if (starts_with(argv[0], "--"))
 592                        argv[0] += 2;
 593        } else {
 594                /* The user didn't specify a command; give them help */
 595                commit_pager_choice();
 596                printf("usage: %s\n\n", git_usage_string);
 597                list_common_cmds_help();
 598                printf("\n%s\n", _(git_more_info_string));
 599                exit(1);
 600        }
 601        cmd = argv[0];
 602
 603        /*
 604         * We use PATH to find git commands, but we prepend some higher
 605         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 606         * environment, and the $(gitexecdir) from the Makefile at build
 607         * time.
 608         */
 609        setup_path();
 610
 611        while (1) {
 612                static int done_help = 0;
 613                static int was_alias = 0;
 614                was_alias = run_argv(&argc, &argv);
 615                if (errno != ENOENT)
 616                        break;
 617                if (was_alias) {
 618                        fprintf(stderr, "Expansion of alias '%s' failed; "
 619                                "'%s' is not a git command\n",
 620                                cmd, argv[0]);
 621                        exit(1);
 622                }
 623                if (!done_help) {
 624                        cmd = argv[0] = help_unknown_cmd(cmd);
 625                        done_help = 1;
 626                } else
 627                        break;
 628        }
 629
 630        fprintf(stderr, "Failed to run command '%s': %s\n",
 631                cmd, strerror(errno));
 632
 633        return 1;
 634}