Andrew's git / gitweb.git / git.c
?
git.con commit Merge branch 'bw/ls-files-recurse-submodules' (1c2b1f7)
   1#include "builtin.h"
   2#include "exec_cmd.h"
   3#include "help.h"
   4#include "run-command.h"
   5
   6const char git_usage_string[] =
   7        "git [--version] [--help] [-C <path>] [-c name=value]\n"
   8        "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
   9        "           [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
  10        "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  11        "           <command> [<args>]";
  12
  13const char git_more_info_string[] =
  14        N_("'git help -a' and 'git help -g' list available subcommands and some\n"
  15           "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  16           "to read about a specific subcommand or concept.");
  17
  18static int use_pager = -1;
  19static char *orig_cwd;
  20static const char *env_names[] = {
  21        GIT_DIR_ENVIRONMENT,
  22        GIT_WORK_TREE_ENVIRONMENT,
  23        GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
  24        GIT_PREFIX_ENVIRONMENT
  25};
  26static char *orig_env[4];
  27static int save_restore_env_balance;
  28
  29static void save_env_before_alias(void)
  30{
  31        int i;
  32
  33        assert(save_restore_env_balance == 0);
  34        save_restore_env_balance = 1;
  35        orig_cwd = xgetcwd();
  36        for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  37                orig_env[i] = getenv(env_names[i]);
  38                if (orig_env[i])
  39                        orig_env[i] = xstrdup(orig_env[i]);
  40        }
  41}
  42
  43static void restore_env(int external_alias)
  44{
  45        int i;
  46
  47        assert(save_restore_env_balance == 1);
  48        save_restore_env_balance = 0;
  49        if (!external_alias && orig_cwd && chdir(orig_cwd))
  50                die_errno("could not move to %s", orig_cwd);
  51        free(orig_cwd);
  52        for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  53                if (external_alias &&
  54                    !strcmp(env_names[i], GIT_PREFIX_ENVIRONMENT))
  55                        continue;
  56                if (orig_env[i]) {
  57                        setenv(env_names[i], orig_env[i], 1);
  58                        free(orig_env[i]);
  59                } else {
  60                        unsetenv(env_names[i]);
  61                }
  62        }
  63}
  64
  65static 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
  78static int handle_options(const char ***argv, int *argc, int *envchanged)
  79{
  80        const char **orig_argv = *argv;
  81
  82        while (*argc > 0) {
  83                const char *cmd = (*argv)[0];
  84                if (cmd[0] != '-')
  85                        break;
  86
  87                /*
  88                 * For legacy reasons, the "version" and "help"
  89                 * commands can be written with "--" prepended
  90                 * to make them look like flags.
  91                 */
  92                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  93                        break;
  94
  95                /*
  96                 * Check remaining flags.
  97                 */
  98                if (skip_prefix(cmd, "--exec-path", &cmd)) {
  99                        if (*cmd == '=')
 100                                git_set_argv_exec_path(cmd + 1);
 101                        else {
 102                                puts(git_exec_path());
 103                                exit(0);
 104                        }
 105                } else if (!strcmp(cmd, "--html-path")) {
 106                        puts(system_path(GIT_HTML_PATH));
 107                        exit(0);
 108                } else if (!strcmp(cmd, "--man-path")) {
 109                        puts(system_path(GIT_MAN_PATH));
 110                        exit(0);
 111                } else if (!strcmp(cmd, "--info-path")) {
 112                        puts(system_path(GIT_INFO_PATH));
 113                        exit(0);
 114                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 115                        use_pager = 1;
 116                } else if (!strcmp(cmd, "--no-pager")) {
 117                        use_pager = 0;
 118                        if (envchanged)
 119                                *envchanged = 1;
 120                } else if (!strcmp(cmd, "--no-replace-objects")) {
 121                        check_replace_refs = 0;
 122                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 123                        if (envchanged)
 124                                *envchanged = 1;
 125                } else if (!strcmp(cmd, "--git-dir")) {
 126                        if (*argc < 2) {
 127                                fprintf(stderr, "No directory given for --git-dir.\n" );
 128                                usage(git_usage_string);
 129                        }
 130                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 131                        if (envchanged)
 132                                *envchanged = 1;
 133                        (*argv)++;
 134                        (*argc)--;
 135                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 136                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 137                        if (envchanged)
 138                                *envchanged = 1;
 139                } else if (!strcmp(cmd, "--namespace")) {
 140                        if (*argc < 2) {
 141                                fprintf(stderr, "No namespace given for --namespace.\n" );
 142                                usage(git_usage_string);
 143                        }
 144                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 145                        if (envchanged)
 146                                *envchanged = 1;
 147                        (*argv)++;
 148                        (*argc)--;
 149                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 150                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 151                        if (envchanged)
 152                                *envchanged = 1;
 153                } else if (!strcmp(cmd, "--work-tree")) {
 154                        if (*argc < 2) {
 155                                fprintf(stderr, "No directory given for --work-tree.\n" );
 156                                usage(git_usage_string);
 157                        }
 158                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 159                        if (envchanged)
 160                                *envchanged = 1;
 161                        (*argv)++;
 162                        (*argc)--;
 163                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 164                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 165                        if (envchanged)
 166                                *envchanged = 1;
 167                } else if (!strcmp(cmd, "--super-prefix")) {
 168                        if (*argc < 2) {
 169                                fprintf(stderr, "No prefix given for --super-prefix.\n" );
 170                                usage(git_usage_string);
 171                        }
 172                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 173                        if (envchanged)
 174                                *envchanged = 1;
 175                        (*argv)++;
 176                        (*argc)--;
 177                } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 178                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 179                        if (envchanged)
 180                                *envchanged = 1;
 181                } else if (!strcmp(cmd, "--bare")) {
 182                        char *cwd = xgetcwd();
 183                        is_bare_repository_cfg = 1;
 184                        setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 185                        free(cwd);
 186                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 187                        if (envchanged)
 188                                *envchanged = 1;
 189                } else if (!strcmp(cmd, "-c")) {
 190                        if (*argc < 2) {
 191                                fprintf(stderr, "-c expects a configuration string\n" );
 192                                usage(git_usage_string);
 193                        }
 194                        git_config_push_parameter((*argv)[1]);
 195                        (*argv)++;
 196                        (*argc)--;
 197                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 198                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 199                        if (envchanged)
 200                                *envchanged = 1;
 201                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 202                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 203                        if (envchanged)
 204                                *envchanged = 1;
 205                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 206                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 207                        if (envchanged)
 208                                *envchanged = 1;
 209                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 210                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 211                        if (envchanged)
 212                                *envchanged = 1;
 213                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 214                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 215                        if (envchanged)
 216                                *envchanged = 1;
 217                } else if (!strcmp(cmd, "--shallow-file")) {
 218                        (*argv)++;
 219                        (*argc)--;
 220                        set_alternate_shallow_file((*argv)[0], 1);
 221                        if (envchanged)
 222                                *envchanged = 1;
 223                } else if (!strcmp(cmd, "-C")) {
 224                        if (*argc < 2) {
 225                                fprintf(stderr, "No directory given for -C.\n" );
 226                                usage(git_usage_string);
 227                        }
 228                        if ((*argv)[1][0]) {
 229                                if (chdir((*argv)[1]))
 230                                        die_errno("Cannot change to '%s'", (*argv)[1]);
 231                                if (envchanged)
 232                                        *envchanged = 1;
 233                        }
 234                        (*argv)++;
 235                        (*argc)--;
 236                } else {
 237                        fprintf(stderr, "Unknown option: %s\n", cmd);
 238                        usage(git_usage_string);
 239                }
 240
 241                (*argv)++;
 242                (*argc)--;
 243        }
 244        return (*argv) - orig_argv;
 245}
 246
 247static int handle_alias(int *argcp, const char ***argv)
 248{
 249        int envchanged = 0, ret = 0, saved_errno = errno;
 250        int count, option_count;
 251        const char **new_argv;
 252        const char *alias_command;
 253        char *alias_string;
 254        int unused_nongit;
 255
 256        save_env_before_alias();
 257        setup_git_directory_gently(&unused_nongit);
 258
 259        alias_command = (*argv)[0];
 260        alias_string = alias_lookup(alias_command);
 261        if (alias_string) {
 262                if (alias_string[0] == '!') {
 263                        struct child_process child = CHILD_PROCESS_INIT;
 264
 265                        commit_pager_choice();
 266                        restore_env(1);
 267
 268                        child.use_shell = 1;
 269                        argv_array_push(&child.args, alias_string + 1);
 270                        argv_array_pushv(&child.args, (*argv) + 1);
 271
 272                        ret = run_command(&child);
 273                        if (ret >= 0)   /* normal exit */
 274                                exit(ret);
 275
 276                        die_errno("While expanding alias '%s': '%s'",
 277                            alias_command, alias_string + 1);
 278                }
 279                count = split_cmdline(alias_string, &new_argv);
 280                if (count < 0)
 281                        die("Bad alias.%s string: %s", alias_command,
 282                            split_cmdline_strerror(count));
 283                option_count = handle_options(&new_argv, &count, &envchanged);
 284                if (envchanged)
 285                        die("alias '%s' changes environment variables\n"
 286                                 "You can use '!git' in the alias to do this.",
 287                                 alias_command);
 288                memmove(new_argv - option_count, new_argv,
 289                                count * sizeof(char *));
 290                new_argv -= option_count;
 291
 292                if (count < 1)
 293                        die("empty alias for %s", alias_command);
 294
 295                if (!strcmp(alias_command, new_argv[0]))
 296                        die("recursive alias: %s", alias_command);
 297
 298                trace_argv_printf(new_argv,
 299                                  "trace: alias expansion: %s =>",
 300                                  alias_command);
 301
 302                REALLOC_ARRAY(new_argv, count + *argcp);
 303                /* insert after command name */
 304                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 305
 306                *argv = new_argv;
 307                *argcp += count - 1;
 308
 309                ret = 1;
 310        }
 311
 312        restore_env(0);
 313
 314        errno = saved_errno;
 315
 316        return ret;
 317}
 318
 319#define RUN_SETUP               (1<<0)
 320#define RUN_SETUP_GENTLY        (1<<1)
 321#define USE_PAGER               (1<<2)
 322/*
 323 * require working tree to be present -- anything uses this needs
 324 * RUN_SETUP for reading from the configuration file.
 325 */
 326#define NEED_WORK_TREE          (1<<3)
 327#define SUPPORT_SUPER_PREFIX    (1<<4)
 328
 329struct cmd_struct {
 330        const char *cmd;
 331        int (*fn)(int, const char **, const char *);
 332        int option;
 333};
 334
 335static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 336{
 337        int status, help;
 338        struct stat st;
 339        const char *prefix;
 340
 341        prefix = NULL;
 342        help = argc == 2 && !strcmp(argv[1], "-h");
 343        if (!help) {
 344                if (p->option & RUN_SETUP)
 345                        prefix = setup_git_directory();
 346                else if (p->option & RUN_SETUP_GENTLY) {
 347                        int nongit_ok;
 348                        prefix = setup_git_directory_gently(&nongit_ok);
 349                }
 350
 351                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
 352                        use_pager = check_pager_config(p->cmd);
 353                if (use_pager == -1 && p->option & USE_PAGER)
 354                        use_pager = 1;
 355
 356                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 357                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 358                        trace_repo_setup(prefix);
 359        }
 360        commit_pager_choice();
 361
 362        if (!help && get_super_prefix()) {
 363                if (!(p->option & SUPPORT_SUPER_PREFIX))
 364                        die("%s doesn't support --super-prefix", p->cmd);
 365                if (prefix)
 366                        die("can't use --super-prefix from a subdirectory");
 367        }
 368
 369        if (!help && p->option & NEED_WORK_TREE)
 370                setup_work_tree();
 371
 372        trace_argv_printf(argv, "trace: built-in: git");
 373
 374        status = p->fn(argc, argv, prefix);
 375        if (status)
 376                return status;
 377
 378        /* Somebody closed stdout? */
 379        if (fstat(fileno(stdout), &st))
 380                return 0;
 381        /* Ignore write errors for pipes and sockets.. */
 382        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 383                return 0;
 384
 385        /* Check for ENOSPC and EIO errors.. */
 386        if (fflush(stdout))
 387                die_errno("write failure on standard output");
 388        if (ferror(stdout))
 389                die("unknown write failure on standard output");
 390        if (fclose(stdout))
 391                die_errno("close failed on standard output");
 392        return 0;
 393}
 394
 395static struct cmd_struct commands[] = {
 396        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 397        { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 398        { "annotate", cmd_annotate, RUN_SETUP },
 399        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 400        { "archive", cmd_archive },
 401        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 402        { "blame", cmd_blame, RUN_SETUP },
 403        { "branch", cmd_branch, RUN_SETUP },
 404        { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 405        { "cat-file", cmd_cat_file, RUN_SETUP },
 406        { "check-attr", cmd_check_attr, RUN_SETUP },
 407        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 408        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 409        { "check-ref-format", cmd_check_ref_format },
 410        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 411        { "checkout-index", cmd_checkout_index,
 412                RUN_SETUP | NEED_WORK_TREE},
 413        { "cherry", cmd_cherry, RUN_SETUP },
 414        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 415        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 416        { "clone", cmd_clone },
 417        { "column", cmd_column, RUN_SETUP_GENTLY },
 418        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 419        { "commit-tree", cmd_commit_tree, RUN_SETUP },
 420        { "config", cmd_config, RUN_SETUP_GENTLY },
 421        { "count-objects", cmd_count_objects, RUN_SETUP },
 422        { "credential", cmd_credential, RUN_SETUP_GENTLY },
 423        { "describe", cmd_describe, RUN_SETUP },
 424        { "diff", cmd_diff },
 425        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 426        { "diff-index", cmd_diff_index, RUN_SETUP },
 427        { "diff-tree", cmd_diff_tree, RUN_SETUP },
 428        { "fast-export", cmd_fast_export, RUN_SETUP },
 429        { "fetch", cmd_fetch, RUN_SETUP },
 430        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 431        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 432        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 433        { "format-patch", cmd_format_patch, RUN_SETUP },
 434        { "fsck", cmd_fsck, RUN_SETUP },
 435        { "fsck-objects", cmd_fsck, RUN_SETUP },
 436        { "gc", cmd_gc, RUN_SETUP },
 437        { "get-tar-commit-id", cmd_get_tar_commit_id },
 438        { "grep", cmd_grep, RUN_SETUP_GENTLY },
 439        { "hash-object", cmd_hash_object },
 440        { "help", cmd_help },
 441        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 442        { "init", cmd_init_db },
 443        { "init-db", cmd_init_db },
 444        { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 445        { "log", cmd_log, RUN_SETUP },
 446        { "ls-files", cmd_ls_files, RUN_SETUP | SUPPORT_SUPER_PREFIX },
 447        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 448        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 449        { "mailinfo", cmd_mailinfo },
 450        { "mailsplit", cmd_mailsplit },
 451        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 452        { "merge-base", cmd_merge_base, RUN_SETUP },
 453        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 454        { "merge-index", cmd_merge_index, RUN_SETUP },
 455        { "merge-ours", cmd_merge_ours, RUN_SETUP },
 456        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 457        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 458        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 459        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 460        { "merge-tree", cmd_merge_tree, RUN_SETUP },
 461        { "mktag", cmd_mktag, RUN_SETUP },
 462        { "mktree", cmd_mktree, RUN_SETUP },
 463        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 464        { "name-rev", cmd_name_rev, RUN_SETUP },
 465        { "notes", cmd_notes, RUN_SETUP },
 466        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 467        { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 468        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 469        { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
 470        { "pickaxe", cmd_blame, RUN_SETUP },
 471        { "prune", cmd_prune, RUN_SETUP },
 472        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 473        { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 474        { "push", cmd_push, RUN_SETUP },
 475        { "read-tree", cmd_read_tree, RUN_SETUP },
 476        { "receive-pack", cmd_receive_pack },
 477        { "reflog", cmd_reflog, RUN_SETUP },
 478        { "remote", cmd_remote, RUN_SETUP },
 479        { "remote-ext", cmd_remote_ext },
 480        { "remote-fd", cmd_remote_fd },
 481        { "repack", cmd_repack, RUN_SETUP },
 482        { "replace", cmd_replace, RUN_SETUP },
 483        { "rerere", cmd_rerere, RUN_SETUP },
 484        { "reset", cmd_reset, RUN_SETUP },
 485        { "rev-list", cmd_rev_list, RUN_SETUP },
 486        { "rev-parse", cmd_rev_parse },
 487        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 488        { "rm", cmd_rm, RUN_SETUP },
 489        { "send-pack", cmd_send_pack, RUN_SETUP },
 490        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 491        { "show", cmd_show, RUN_SETUP },
 492        { "show-branch", cmd_show_branch, RUN_SETUP },
 493        { "show-ref", cmd_show_ref, RUN_SETUP },
 494        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 495        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 496        { "stripspace", cmd_stripspace },
 497        { "submodule--helper", cmd_submodule__helper, RUN_SETUP },
 498        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 499        { "tag", cmd_tag, RUN_SETUP },
 500        { "unpack-file", cmd_unpack_file, RUN_SETUP },
 501        { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 502        { "update-index", cmd_update_index, RUN_SETUP },
 503        { "update-ref", cmd_update_ref, RUN_SETUP },
 504        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 505        { "upload-archive", cmd_upload_archive },
 506        { "upload-archive--writer", cmd_upload_archive_writer },
 507        { "var", cmd_var, RUN_SETUP_GENTLY },
 508        { "verify-commit", cmd_verify_commit, RUN_SETUP },
 509        { "verify-pack", cmd_verify_pack },
 510        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 511        { "version", cmd_version },
 512        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 513        { "worktree", cmd_worktree, RUN_SETUP },
 514        { "write-tree", cmd_write_tree, RUN_SETUP },
 515};
 516
 517static struct cmd_struct *get_builtin(const char *s)
 518{
 519        int i;
 520        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 521                struct cmd_struct *p = commands + i;
 522                if (!strcmp(s, p->cmd))
 523                        return p;
 524        }
 525        return NULL;
 526}
 527
 528int is_builtin(const char *s)
 529{
 530        return !!get_builtin(s);
 531}
 532
 533#ifdef STRIP_EXTENSION
 534static void strip_extension(const char **argv)
 535{
 536        size_t len;
 537
 538        if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 539                argv[0] = xmemdupz(argv[0], len);
 540}
 541#else
 542#define strip_extension(cmd)
 543#endif
 544
 545static void handle_builtin(int argc, const char **argv)
 546{
 547        struct argv_array args = ARGV_ARRAY_INIT;
 548        const char *cmd;
 549        struct cmd_struct *builtin;
 550
 551        strip_extension(argv);
 552        cmd = argv[0];
 553
 554        /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 555        if (argc > 1 && !strcmp(argv[1], "--help")) {
 556                int i;
 557
 558                argv[1] = argv[0];
 559                argv[0] = cmd = "help";
 560
 561                for (i = 0; i < argc; i++) {
 562                        argv_array_push(&args, argv[i]);
 563                        if (!i)
 564                                argv_array_push(&args, "--exclude-guides");
 565                }
 566
 567                argc++;
 568                argv = args.argv;
 569        }
 570
 571        builtin = get_builtin(cmd);
 572        if (builtin)
 573                exit(run_builtin(builtin, argc, argv));
 574        argv_array_clear(&args);
 575}
 576
 577static void execv_dashed_external(const char **argv)
 578{
 579        struct strbuf cmd = STRBUF_INIT;
 580        const char *tmp;
 581        int status;
 582
 583        if (get_super_prefix())
 584                die("%s doesn't support --super-prefix", argv[0]);
 585
 586        if (use_pager == -1)
 587                use_pager = check_pager_config(argv[0]);
 588        commit_pager_choice();
 589
 590        strbuf_addf(&cmd, "git-%s", argv[0]);
 591
 592        /*
 593         * argv[0] must be the git command, but the argv array
 594         * belongs to the caller, and may be reused in
 595         * subsequent loop iterations. Save argv[0] and
 596         * restore it on error.
 597         */
 598        tmp = argv[0];
 599        argv[0] = cmd.buf;
 600
 601        trace_argv_printf(argv, "trace: exec:");
 602
 603        /*
 604         * if we fail because the command is not found, it is
 605         * OK to return. Otherwise, we just pass along the status code.
 606         */
 607        status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
 608        if (status >= 0 || errno != ENOENT)
 609                exit(status);
 610
 611        argv[0] = tmp;
 612
 613        strbuf_release(&cmd);
 614}
 615
 616static int run_argv(int *argcp, const char ***argv)
 617{
 618        int done_alias = 0;
 619
 620        while (1) {
 621                /*
 622                 * If we tried alias and futzed with our environment,
 623                 * it no longer is safe to invoke builtins directly in
 624                 * general.  We have to spawn them as dashed externals.
 625                 *
 626                 * NEEDSWORK: if we can figure out cases
 627                 * where it is safe to do, we can avoid spawning a new
 628                 * process.
 629                 */
 630                if (!done_alias)
 631                        handle_builtin(*argcp, *argv);
 632
 633                /* .. then try the external ones */
 634                execv_dashed_external(*argv);
 635
 636                /* It could be an alias -- this works around the insanity
 637                 * of overriding "git log" with "git show" by having
 638                 * alias.log = show
 639                 */
 640                if (done_alias)
 641                        break;
 642                if (!handle_alias(argcp, argv))
 643                        break;
 644                done_alias = 1;
 645        }
 646
 647        return done_alias;
 648}
 649
 650int cmd_main(int argc, const char **argv)
 651{
 652        const char *cmd;
 653        int done_help = 0;
 654
 655        cmd = argv[0];
 656        if (!cmd)
 657                cmd = "git-help";
 658
 659        trace_command_performance(argv);
 660
 661        /*
 662         * "git-xxxx" is the same as "git xxxx", but we obviously:
 663         *
 664         *  - cannot take flags in between the "git" and the "xxxx".
 665         *  - cannot execute it externally (since it would just do
 666         *    the same thing over again)
 667         *
 668         * So we just directly call the builtin handler, and die if
 669         * that one cannot handle it.
 670         */
 671        if (skip_prefix(cmd, "git-", &cmd)) {
 672                argv[0] = cmd;
 673                handle_builtin(argc, argv);
 674                die("cannot handle %s as a builtin", cmd);
 675        }
 676
 677        /* Look for flags.. */
 678        argv++;
 679        argc--;
 680        handle_options(&argv, &argc, NULL);
 681        if (argc > 0) {
 682                /* translate --help and --version into commands */
 683                skip_prefix(argv[0], "--", &argv[0]);
 684        } else {
 685                /* The user didn't specify a command; give them help */
 686                commit_pager_choice();
 687                printf("usage: %s\n\n", git_usage_string);
 688                list_common_cmds_help();
 689                printf("\n%s\n", _(git_more_info_string));
 690                exit(1);
 691        }
 692        cmd = argv[0];
 693
 694        /*
 695         * We use PATH to find git commands, but we prepend some higher
 696         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 697         * environment, and the $(gitexecdir) from the Makefile at build
 698         * time.
 699         */
 700        setup_path();
 701
 702        while (1) {
 703                int was_alias = run_argv(&argc, &argv);
 704                if (errno != ENOENT)
 705                        break;
 706                if (was_alias) {
 707                        fprintf(stderr, "Expansion of alias '%s' failed; "
 708                                "'%s' is not a git command\n",
 709                                cmd, argv[0]);
 710                        exit(1);
 711                }
 712                if (!done_help) {
 713                        cmd = argv[0] = help_unknown_cmd(cmd);
 714                        done_help = 1;
 715                } else
 716                        break;
 717        }
 718
 719        fprintf(stderr, "Failed to run command '%s': %s\n",
 720                cmd, strerror(errno));
 721
 722        return 1;
 723}