git.con commit fmt-merge-msg: plug small leak of commit buffer (1154aa4)
   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 (starts_with(cmd, "--exec-path")) {
  58                        cmd += 11;
  59                        if (*cmd == '=')
  60                                git_set_argv_exec_path(cmd + 1);
  61                        else {
  62                                puts(git_exec_path());
  63                                exit(0);
  64                        }
  65                } else if (!strcmp(cmd, "--html-path")) {
  66                        puts(system_path(GIT_HTML_PATH));
  67                        exit(0);
  68                } else if (!strcmp(cmd, "--man-path")) {
  69                        puts(system_path(GIT_MAN_PATH));
  70                        exit(0);
  71                } else if (!strcmp(cmd, "--info-path")) {
  72                        puts(system_path(GIT_INFO_PATH));
  73                        exit(0);
  74                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  75                        use_pager = 1;
  76                } else if (!strcmp(cmd, "--no-pager")) {
  77                        use_pager = 0;
  78                        if (envchanged)
  79                                *envchanged = 1;
  80                } else if (!strcmp(cmd, "--no-replace-objects")) {
  81                        check_replace_refs = 0;
  82                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  83                        if (envchanged)
  84                                *envchanged = 1;
  85                } else if (!strcmp(cmd, "--git-dir")) {
  86                        if (*argc < 2) {
  87                                fprintf(stderr, "No directory given for --git-dir.\n" );
  88                                usage(git_usage_string);
  89                        }
  90                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
  91                        if (envchanged)
  92                                *envchanged = 1;
  93                        (*argv)++;
  94                        (*argc)--;
  95                } else if (starts_with(cmd, "--git-dir=")) {
  96                        setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
  97                        if (envchanged)
  98                                *envchanged = 1;
  99                } else if (!strcmp(cmd, "--namespace")) {
 100                        if (*argc < 2) {
 101                                fprintf(stderr, "No namespace given for --namespace.\n" );
 102                                usage(git_usage_string);
 103                        }
 104                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 105                        if (envchanged)
 106                                *envchanged = 1;
 107                        (*argv)++;
 108                        (*argc)--;
 109                } else if (starts_with(cmd, "--namespace=")) {
 110                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd + 12, 1);
 111                        if (envchanged)
 112                                *envchanged = 1;
 113                } else if (!strcmp(cmd, "--work-tree")) {
 114                        if (*argc < 2) {
 115                                fprintf(stderr, "No directory given for --work-tree.\n" );
 116                                usage(git_usage_string);
 117                        }
 118                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 119                        if (envchanged)
 120                                *envchanged = 1;
 121                        (*argv)++;
 122                        (*argc)--;
 123                } else if (starts_with(cmd, "--work-tree=")) {
 124                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
 125                        if (envchanged)
 126                                *envchanged = 1;
 127                } else if (!strcmp(cmd, "--bare")) {
 128                        static char git_dir[PATH_MAX+1];
 129                        is_bare_repository_cfg = 1;
 130                        setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 131                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 132                        if (envchanged)
 133                                *envchanged = 1;
 134                } else if (!strcmp(cmd, "-c")) {
 135                        if (*argc < 2) {
 136                                fprintf(stderr, "-c expects a configuration string\n" );
 137                                usage(git_usage_string);
 138                        }
 139                        git_config_push_parameter((*argv)[1]);
 140                        (*argv)++;
 141                        (*argc)--;
 142                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 143                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 144                        if (envchanged)
 145                                *envchanged = 1;
 146                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 147                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 148                        if (envchanged)
 149                                *envchanged = 1;
 150                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 151                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 152                        if (envchanged)
 153                                *envchanged = 1;
 154                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 155                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 156                        if (envchanged)
 157                                *envchanged = 1;
 158                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 159                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 160                        if (envchanged)
 161                                *envchanged = 1;
 162                } else if (!strcmp(cmd, "--shallow-file")) {
 163                        (*argv)++;
 164                        (*argc)--;
 165                        set_alternate_shallow_file((*argv)[0], 1);
 166                        if (envchanged)
 167                                *envchanged = 1;
 168                } else if (!strcmp(cmd, "-C")) {
 169                        if (*argc < 2) {
 170                                fprintf(stderr, "No directory given for -C.\n" );
 171                                usage(git_usage_string);
 172                        }
 173                        if (chdir((*argv)[1]))
 174                                die_errno("Cannot change to '%s'", (*argv)[1]);
 175                        if (envchanged)
 176                                *envchanged = 1;
 177                        (*argv)++;
 178                        (*argc)--;
 179                } else {
 180                        fprintf(stderr, "Unknown option: %s\n", cmd);
 181                        usage(git_usage_string);
 182                }
 183
 184                (*argv)++;
 185                (*argc)--;
 186        }
 187        return (*argv) - orig_argv;
 188}
 189
 190static int handle_alias(int *argcp, const char ***argv)
 191{
 192        int envchanged = 0, ret = 0, saved_errno = errno;
 193        const char *subdir;
 194        int count, option_count;
 195        const char **new_argv;
 196        const char *alias_command;
 197        char *alias_string;
 198        int unused_nongit;
 199
 200        subdir = setup_git_directory_gently(&unused_nongit);
 201
 202        alias_command = (*argv)[0];
 203        alias_string = alias_lookup(alias_command);
 204        if (alias_string) {
 205                if (alias_string[0] == '!') {
 206                        const char **alias_argv;
 207                        int argc = *argcp, i;
 208
 209                        commit_pager_choice();
 210
 211                        /* build alias_argv */
 212                        alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 1));
 213                        alias_argv[0] = alias_string + 1;
 214                        for (i = 1; i < argc; ++i)
 215                                alias_argv[i] = (*argv)[i];
 216                        alias_argv[argc] = NULL;
 217
 218                        ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
 219                        if (ret >= 0)   /* normal exit */
 220                                exit(ret);
 221
 222                        die_errno("While expanding alias '%s': '%s'",
 223                            alias_command, alias_string + 1);
 224                }
 225                count = split_cmdline(alias_string, &new_argv);
 226                if (count < 0)
 227                        die("Bad alias.%s string: %s", alias_command,
 228                            split_cmdline_strerror(count));
 229                option_count = handle_options(&new_argv, &count, &envchanged);
 230                if (envchanged)
 231                        die("alias '%s' changes environment variables\n"
 232                                 "You can use '!git' in the alias to do this.",
 233                                 alias_command);
 234                memmove(new_argv - option_count, new_argv,
 235                                count * sizeof(char *));
 236                new_argv -= option_count;
 237
 238                if (count < 1)
 239                        die("empty alias for %s", alias_command);
 240
 241                if (!strcmp(alias_command, new_argv[0]))
 242                        die("recursive alias: %s", alias_command);
 243
 244                trace_argv_printf(new_argv,
 245                                  "trace: alias expansion: %s =>",
 246                                  alias_command);
 247
 248                new_argv = xrealloc(new_argv, sizeof(char *) *
 249                                    (count + *argcp));
 250                /* insert after command name */
 251                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 252
 253                *argv = new_argv;
 254                *argcp += count - 1;
 255
 256                ret = 1;
 257        }
 258
 259        if (subdir && chdir(subdir))
 260                die_errno("Cannot change to '%s'", subdir);
 261
 262        errno = saved_errno;
 263
 264        return ret;
 265}
 266
 267#define RUN_SETUP               (1<<0)
 268#define RUN_SETUP_GENTLY        (1<<1)
 269#define USE_PAGER               (1<<2)
 270/*
 271 * require working tree to be present -- anything uses this needs
 272 * RUN_SETUP for reading from the configuration file.
 273 */
 274#define NEED_WORK_TREE          (1<<3)
 275
 276struct cmd_struct {
 277        const char *cmd;
 278        int (*fn)(int, const char **, const char *);
 279        int option;
 280};
 281
 282static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 283{
 284        int status, help;
 285        struct stat st;
 286        const char *prefix;
 287
 288        prefix = NULL;
 289        help = argc == 2 && !strcmp(argv[1], "-h");
 290        if (!help) {
 291                if (p->option & RUN_SETUP)
 292                        prefix = setup_git_directory();
 293                if (p->option & RUN_SETUP_GENTLY) {
 294                        int nongit_ok;
 295                        prefix = setup_git_directory_gently(&nongit_ok);
 296                }
 297
 298                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
 299                        use_pager = check_pager_config(p->cmd);
 300                if (use_pager == -1 && p->option & USE_PAGER)
 301                        use_pager = 1;
 302
 303                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 304                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 305                        trace_repo_setup(prefix);
 306        }
 307        commit_pager_choice();
 308
 309        if (!help && p->option & NEED_WORK_TREE)
 310                setup_work_tree();
 311
 312        trace_argv_printf(argv, "trace: built-in: git");
 313
 314        status = p->fn(argc, argv, prefix);
 315        if (status)
 316                return status;
 317
 318        /* Somebody closed stdout? */
 319        if (fstat(fileno(stdout), &st))
 320                return 0;
 321        /* Ignore write errors for pipes and sockets.. */
 322        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 323                return 0;
 324
 325        /* Check for ENOSPC and EIO errors.. */
 326        if (fflush(stdout))
 327                die_errno("write failure on standard output");
 328        if (ferror(stdout))
 329                die("unknown write failure on standard output");
 330        if (fclose(stdout))
 331                die_errno("close failed on standard output");
 332        return 0;
 333}
 334
 335static struct cmd_struct commands[] = {
 336        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 337        { "annotate", cmd_annotate, RUN_SETUP },
 338        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 339        { "archive", cmd_archive },
 340        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 341        { "blame", cmd_blame, RUN_SETUP },
 342        { "branch", cmd_branch, RUN_SETUP },
 343        { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 344        { "cat-file", cmd_cat_file, RUN_SETUP },
 345        { "check-attr", cmd_check_attr, RUN_SETUP },
 346        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 347        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 348        { "check-ref-format", cmd_check_ref_format },
 349        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 350        { "checkout-index", cmd_checkout_index,
 351                RUN_SETUP | NEED_WORK_TREE},
 352        { "cherry", cmd_cherry, RUN_SETUP },
 353        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 354        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 355        { "clone", cmd_clone },
 356        { "column", cmd_column, RUN_SETUP_GENTLY },
 357        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 358        { "commit-tree", cmd_commit_tree, RUN_SETUP },
 359        { "config", cmd_config, RUN_SETUP_GENTLY },
 360        { "count-objects", cmd_count_objects, RUN_SETUP },
 361        { "credential", cmd_credential, RUN_SETUP_GENTLY },
 362        { "describe", cmd_describe, RUN_SETUP },
 363        { "diff", cmd_diff },
 364        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 365        { "diff-index", cmd_diff_index, RUN_SETUP },
 366        { "diff-tree", cmd_diff_tree, RUN_SETUP },
 367        { "fast-export", cmd_fast_export, RUN_SETUP },
 368        { "fetch", cmd_fetch, RUN_SETUP },
 369        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 370        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 371        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 372        { "format-patch", cmd_format_patch, RUN_SETUP },
 373        { "fsck", cmd_fsck, RUN_SETUP },
 374        { "fsck-objects", cmd_fsck, RUN_SETUP },
 375        { "gc", cmd_gc, RUN_SETUP },
 376        { "get-tar-commit-id", cmd_get_tar_commit_id },
 377        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 378        { "hash-object", cmd_hash_object },
 379        { "help", cmd_help },
 380        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 381        { "init", cmd_init_db },
 382        { "init-db", cmd_init_db },
 383        { "log", cmd_log, RUN_SETUP },
 384        { "ls-files", cmd_ls_files, RUN_SETUP },
 385        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 386        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 387        { "mailinfo", cmd_mailinfo },
 388        { "mailsplit", cmd_mailsplit },
 389        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 390        { "merge-base", cmd_merge_base, RUN_SETUP },
 391        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 392        { "merge-index", cmd_merge_index, RUN_SETUP },
 393        { "merge-ours", cmd_merge_ours, RUN_SETUP },
 394        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 395        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 396        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 397        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 398        { "merge-tree", cmd_merge_tree, RUN_SETUP },
 399        { "mktag", cmd_mktag, RUN_SETUP },
 400        { "mktree", cmd_mktree, RUN_SETUP },
 401        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 402        { "name-rev", cmd_name_rev, RUN_SETUP },
 403        { "notes", cmd_notes, RUN_SETUP },
 404        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 405        { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 406        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 407        { "patch-id", cmd_patch_id },
 408        { "pickaxe", cmd_blame, RUN_SETUP },
 409        { "prune", cmd_prune, RUN_SETUP },
 410        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 411        { "push", cmd_push, RUN_SETUP },
 412        { "read-tree", cmd_read_tree, RUN_SETUP },
 413        { "receive-pack", cmd_receive_pack },
 414        { "reflog", cmd_reflog, RUN_SETUP },
 415        { "remote", cmd_remote, RUN_SETUP },
 416        { "remote-ext", cmd_remote_ext },
 417        { "remote-fd", cmd_remote_fd },
 418        { "repack", cmd_repack, RUN_SETUP },
 419        { "replace", cmd_replace, RUN_SETUP },
 420        { "rerere", cmd_rerere, RUN_SETUP },
 421        { "reset", cmd_reset, RUN_SETUP },
 422        { "rev-list", cmd_rev_list, RUN_SETUP },
 423        { "rev-parse", cmd_rev_parse },
 424        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 425        { "rm", cmd_rm, RUN_SETUP },
 426        { "send-pack", cmd_send_pack, RUN_SETUP },
 427        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 428        { "show", cmd_show, RUN_SETUP },
 429        { "show-branch", cmd_show_branch, RUN_SETUP },
 430        { "show-ref", cmd_show_ref, RUN_SETUP },
 431        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 432        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 433        { "stripspace", cmd_stripspace },
 434        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 435        { "tag", cmd_tag, RUN_SETUP },
 436        { "unpack-file", cmd_unpack_file, RUN_SETUP },
 437        { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 438        { "update-index", cmd_update_index, RUN_SETUP },
 439        { "update-ref", cmd_update_ref, RUN_SETUP },
 440        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 441        { "upload-archive", cmd_upload_archive },
 442        { "upload-archive--writer", cmd_upload_archive_writer },
 443        { "var", cmd_var, RUN_SETUP_GENTLY },
 444        { "verify-pack", cmd_verify_pack },
 445        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 446        { "version", cmd_version },
 447        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 448        { "write-tree", cmd_write_tree, RUN_SETUP },
 449};
 450
 451int is_builtin(const char *s)
 452{
 453        int i;
 454        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 455                struct cmd_struct *p = commands+i;
 456                if (!strcmp(s, p->cmd))
 457                        return 1;
 458        }
 459        return 0;
 460}
 461
 462static void handle_builtin(int argc, const char **argv)
 463{
 464        const char *cmd = argv[0];
 465        int i;
 466        static const char ext[] = STRIP_EXTENSION;
 467
 468        if (sizeof(ext) > 1) {
 469                i = strlen(argv[0]) - strlen(ext);
 470                if (i > 0 && !strcmp(argv[0] + i, ext)) {
 471                        char *argv0 = xstrdup(argv[0]);
 472                        argv[0] = cmd = argv0;
 473                        argv0[i] = '\0';
 474                }
 475        }
 476
 477        /* Turn "git cmd --help" into "git help cmd" */
 478        if (argc > 1 && !strcmp(argv[1], "--help")) {
 479                argv[1] = argv[0];
 480                argv[0] = cmd = "help";
 481        }
 482
 483        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 484                struct cmd_struct *p = commands+i;
 485                if (strcmp(p->cmd, cmd))
 486                        continue;
 487                exit(run_builtin(p, argc, argv));
 488        }
 489}
 490
 491static void execv_dashed_external(const char **argv)
 492{
 493        struct strbuf cmd = STRBUF_INIT;
 494        const char *tmp;
 495        int status;
 496
 497        if (use_pager == -1)
 498                use_pager = check_pager_config(argv[0]);
 499        commit_pager_choice();
 500
 501        strbuf_addf(&cmd, "git-%s", argv[0]);
 502
 503        /*
 504         * argv[0] must be the git command, but the argv array
 505         * belongs to the caller, and may be reused in
 506         * subsequent loop iterations. Save argv[0] and
 507         * restore it on error.
 508         */
 509        tmp = argv[0];
 510        argv[0] = cmd.buf;
 511
 512        trace_argv_printf(argv, "trace: exec:");
 513
 514        /*
 515         * if we fail because the command is not found, it is
 516         * OK to return. Otherwise, we just pass along the status code.
 517         */
 518        status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
 519        if (status >= 0 || errno != ENOENT)
 520                exit(status);
 521
 522        argv[0] = tmp;
 523
 524        strbuf_release(&cmd);
 525}
 526
 527static int run_argv(int *argcp, const char ***argv)
 528{
 529        int done_alias = 0;
 530
 531        while (1) {
 532                /* See if it's a builtin */
 533                handle_builtin(*argcp, *argv);
 534
 535                /* .. then try the external ones */
 536                execv_dashed_external(*argv);
 537
 538                /* It could be an alias -- this works around the insanity
 539                 * of overriding "git log" with "git show" by having
 540                 * alias.log = show
 541                 */
 542                if (done_alias || !handle_alias(argcp, argv))
 543                        break;
 544                done_alias = 1;
 545        }
 546
 547        return done_alias;
 548}
 549
 550
 551int main(int argc, char **av)
 552{
 553        const char **argv = (const char **) av;
 554        const char *cmd;
 555
 556        startup_info = &git_startup_info;
 557
 558        cmd = git_extract_argv0_path(argv[0]);
 559        if (!cmd)
 560                cmd = "git-help";
 561
 562        /*
 563         * Always open file descriptors 0/1/2 to avoid clobbering files
 564         * in die().  It also avoids messing up when the pipes are dup'ed
 565         * onto stdin/stdout/stderr in the child processes we spawn.
 566         */
 567        sanitize_stdfds();
 568
 569        git_setup_gettext();
 570
 571        /*
 572         * "git-xxxx" is the same as "git xxxx", but we obviously:
 573         *
 574         *  - cannot take flags in between the "git" and the "xxxx".
 575         *  - cannot execute it externally (since it would just do
 576         *    the same thing over again)
 577         *
 578         * So we just directly call the builtin handler, and die if
 579         * that one cannot handle it.
 580         */
 581        if (starts_with(cmd, "git-")) {
 582                cmd += 4;
 583                argv[0] = cmd;
 584                handle_builtin(argc, argv);
 585                die("cannot handle %s as a builtin", cmd);
 586        }
 587
 588        /* Look for flags.. */
 589        argv++;
 590        argc--;
 591        handle_options(&argv, &argc, NULL);
 592        if (argc > 0) {
 593                if (starts_with(argv[0], "--"))
 594                        argv[0] += 2;
 595        } else {
 596                /* The user didn't specify a command; give them help */
 597                commit_pager_choice();
 598                printf("usage: %s\n\n", git_usage_string);
 599                list_common_cmds_help();
 600                printf("\n%s\n", _(git_more_info_string));
 601                exit(1);
 602        }
 603        cmd = argv[0];
 604
 605        /*
 606         * We use PATH to find git commands, but we prepend some higher
 607         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 608         * environment, and the $(gitexecdir) from the Makefile at build
 609         * time.
 610         */
 611        setup_path();
 612
 613        while (1) {
 614                static int done_help = 0;
 615                static int was_alias = 0;
 616                was_alias = run_argv(&argc, &argv);
 617                if (errno != ENOENT)
 618                        break;
 619                if (was_alias) {
 620                        fprintf(stderr, "Expansion of alias '%s' failed; "
 621                                "'%s' is not a git command\n",
 622                                cmd, argv[0]);
 623                        exit(1);
 624                }
 625                if (!done_help) {
 626                        cmd = argv[0] = help_unknown_cmd(cmd);
 627                        done_help = 1;
 628                } else
 629                        break;
 630        }
 631
 632        fprintf(stderr, "Failed to run command '%s': %s\n",
 633                cmd, strerror(errno));
 634
 635        return 1;
 636}