Andrew's git / gitweb.git / git.c
?
git.con commit Documentation/git-submodule: cleanup "add" section (beebc6d)
   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 list_builtins(void);
  30
  31static void save_env_before_alias(void)
  32{
  33        int i;
  34
  35        assert(save_restore_env_balance == 0);
  36        save_restore_env_balance = 1;
  37        orig_cwd = xgetcwd();
  38        for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  39                orig_env[i] = getenv(env_names[i]);
  40                orig_env[i] = xstrdup_or_null(orig_env[i]);
  41        }
  42}
  43
  44static void restore_env(int external_alias)
  45{
  46        int i;
  47
  48        assert(save_restore_env_balance == 1);
  49        save_restore_env_balance = 0;
  50        if (!external_alias && orig_cwd && chdir(orig_cwd))
  51                die_errno("could not move to %s", orig_cwd);
  52        free(orig_cwd);
  53        for (i = 0; i < ARRAY_SIZE(env_names); i++) {
  54                if (external_alias &&
  55                    !strcmp(env_names[i], GIT_PREFIX_ENVIRONMENT))
  56                        continue;
  57                if (orig_env[i]) {
  58                        setenv(env_names[i], orig_env[i], 1);
  59                        free(orig_env[i]);
  60                } else {
  61                        unsetenv(env_names[i]);
  62                }
  63        }
  64}
  65
  66static void commit_pager_choice(void) {
  67        switch (use_pager) {
  68        case 0:
  69                setenv("GIT_PAGER", "cat", 1);
  70                break;
  71        case 1:
  72                setup_pager();
  73                break;
  74        default:
  75                break;
  76        }
  77}
  78
  79static int handle_options(const char ***argv, int *argc, int *envchanged)
  80{
  81        const char **orig_argv = *argv;
  82
  83        while (*argc > 0) {
  84                const char *cmd = (*argv)[0];
  85                if (cmd[0] != '-')
  86                        break;
  87
  88                /*
  89                 * For legacy reasons, the "version" and "help"
  90                 * commands can be written with "--" prepended
  91                 * to make them look like flags.
  92                 */
  93                if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  94                        break;
  95
  96                /*
  97                 * Check remaining flags.
  98                 */
  99                if (skip_prefix(cmd, "--exec-path", &cmd)) {
 100                        if (*cmd == '=')
 101                                git_set_argv_exec_path(cmd + 1);
 102                        else {
 103                                puts(git_exec_path());
 104                                exit(0);
 105                        }
 106                } else if (!strcmp(cmd, "--html-path")) {
 107                        puts(system_path(GIT_HTML_PATH));
 108                        exit(0);
 109                } else if (!strcmp(cmd, "--man-path")) {
 110                        puts(system_path(GIT_MAN_PATH));
 111                        exit(0);
 112                } else if (!strcmp(cmd, "--info-path")) {
 113                        puts(system_path(GIT_INFO_PATH));
 114                        exit(0);
 115                } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 116                        use_pager = 1;
 117                } else if (!strcmp(cmd, "--no-pager")) {
 118                        use_pager = 0;
 119                        if (envchanged)
 120                                *envchanged = 1;
 121                } else if (!strcmp(cmd, "--no-replace-objects")) {
 122                        check_replace_refs = 0;
 123                        setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 124                        if (envchanged)
 125                                *envchanged = 1;
 126                } else if (!strcmp(cmd, "--git-dir")) {
 127                        if (*argc < 2) {
 128                                fprintf(stderr, "No directory given for --git-dir.\n" );
 129                                usage(git_usage_string);
 130                        }
 131                        setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
 132                        if (envchanged)
 133                                *envchanged = 1;
 134                        (*argv)++;
 135                        (*argc)--;
 136                } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 137                        setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 138                        if (envchanged)
 139                                *envchanged = 1;
 140                } else if (!strcmp(cmd, "--namespace")) {
 141                        if (*argc < 2) {
 142                                fprintf(stderr, "No namespace given for --namespace.\n" );
 143                                usage(git_usage_string);
 144                        }
 145                        setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 146                        if (envchanged)
 147                                *envchanged = 1;
 148                        (*argv)++;
 149                        (*argc)--;
 150                } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 151                        setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 152                        if (envchanged)
 153                                *envchanged = 1;
 154                } else if (!strcmp(cmd, "--work-tree")) {
 155                        if (*argc < 2) {
 156                                fprintf(stderr, "No directory given for --work-tree.\n" );
 157                                usage(git_usage_string);
 158                        }
 159                        setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 160                        if (envchanged)
 161                                *envchanged = 1;
 162                        (*argv)++;
 163                        (*argc)--;
 164                } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 165                        setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 166                        if (envchanged)
 167                                *envchanged = 1;
 168                } else if (!strcmp(cmd, "--super-prefix")) {
 169                        if (*argc < 2) {
 170                                fprintf(stderr, "No prefix given for --super-prefix.\n" );
 171                                usage(git_usage_string);
 172                        }
 173                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 174                        if (envchanged)
 175                                *envchanged = 1;
 176                        (*argv)++;
 177                        (*argc)--;
 178                } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 179                        setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 180                        if (envchanged)
 181                                *envchanged = 1;
 182                } else if (!strcmp(cmd, "--bare")) {
 183                        char *cwd = xgetcwd();
 184                        is_bare_repository_cfg = 1;
 185                        setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 186                        free(cwd);
 187                        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 188                        if (envchanged)
 189                                *envchanged = 1;
 190                } else if (!strcmp(cmd, "-c")) {
 191                        if (*argc < 2) {
 192                                fprintf(stderr, "-c expects a configuration string\n" );
 193                                usage(git_usage_string);
 194                        }
 195                        git_config_push_parameter((*argv)[1]);
 196                        (*argv)++;
 197                        (*argc)--;
 198                } else if (!strcmp(cmd, "--literal-pathspecs")) {
 199                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 200                        if (envchanged)
 201                                *envchanged = 1;
 202                } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 203                        setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 204                        if (envchanged)
 205                                *envchanged = 1;
 206                } else if (!strcmp(cmd, "--glob-pathspecs")) {
 207                        setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 208                        if (envchanged)
 209                                *envchanged = 1;
 210                } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 211                        setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 212                        if (envchanged)
 213                                *envchanged = 1;
 214                } else if (!strcmp(cmd, "--icase-pathspecs")) {
 215                        setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 216                        if (envchanged)
 217                                *envchanged = 1;
 218                } else if (!strcmp(cmd, "--shallow-file")) {
 219                        (*argv)++;
 220                        (*argc)--;
 221                        set_alternate_shallow_file((*argv)[0], 1);
 222                        if (envchanged)
 223                                *envchanged = 1;
 224                } else if (!strcmp(cmd, "-C")) {
 225                        if (*argc < 2) {
 226                                fprintf(stderr, "No directory given for -C.\n" );
 227                                usage(git_usage_string);
 228                        }
 229                        if ((*argv)[1][0]) {
 230                                if (chdir((*argv)[1]))
 231                                        die_errno("Cannot change to '%s'", (*argv)[1]);
 232                                if (envchanged)
 233                                        *envchanged = 1;
 234                        }
 235                        (*argv)++;
 236                        (*argc)--;
 237                } else if (!strcmp(cmd, "--list-builtins")) {
 238                        list_builtins();
 239                        exit(0);
 240                } else {
 241                        fprintf(stderr, "Unknown option: %s\n", cmd);
 242                        usage(git_usage_string);
 243                }
 244
 245                (*argv)++;
 246                (*argc)--;
 247        }
 248        return (*argv) - orig_argv;
 249}
 250
 251static int handle_alias(int *argcp, const char ***argv)
 252{
 253        int envchanged = 0, ret = 0, saved_errno = errno;
 254        int count, option_count;
 255        const char **new_argv;
 256        const char *alias_command;
 257        char *alias_string;
 258        int unused_nongit;
 259
 260        save_env_before_alias();
 261        setup_git_directory_gently(&unused_nongit);
 262
 263        alias_command = (*argv)[0];
 264        alias_string = alias_lookup(alias_command);
 265        if (alias_string) {
 266                if (alias_string[0] == '!') {
 267                        struct child_process child = CHILD_PROCESS_INIT;
 268
 269                        commit_pager_choice();
 270                        restore_env(1);
 271
 272                        child.use_shell = 1;
 273                        argv_array_push(&child.args, alias_string + 1);
 274                        argv_array_pushv(&child.args, (*argv) + 1);
 275
 276                        ret = run_command(&child);
 277                        if (ret >= 0)   /* normal exit */
 278                                exit(ret);
 279
 280                        die_errno("While expanding alias '%s': '%s'",
 281                            alias_command, alias_string + 1);
 282                }
 283                count = split_cmdline(alias_string, &new_argv);
 284                if (count < 0)
 285                        die("Bad alias.%s string: %s", alias_command,
 286                            split_cmdline_strerror(count));
 287                option_count = handle_options(&new_argv, &count, &envchanged);
 288                if (envchanged)
 289                        die("alias '%s' changes environment variables\n"
 290                                 "You can use '!git' in the alias to do this.",
 291                                 alias_command);
 292                memmove(new_argv - option_count, new_argv,
 293                                count * sizeof(char *));
 294                new_argv -= option_count;
 295
 296                if (count < 1)
 297                        die("empty alias for %s", alias_command);
 298
 299                if (!strcmp(alias_command, new_argv[0]))
 300                        die("recursive alias: %s", alias_command);
 301
 302                trace_argv_printf(new_argv,
 303                                  "trace: alias expansion: %s =>",
 304                                  alias_command);
 305
 306                REALLOC_ARRAY(new_argv, count + *argcp);
 307                /* insert after command name */
 308                memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 309
 310                *argv = new_argv;
 311                *argcp += count - 1;
 312
 313                ret = 1;
 314        }
 315
 316        restore_env(0);
 317
 318        errno = saved_errno;
 319
 320        return ret;
 321}
 322
 323#define RUN_SETUP               (1<<0)
 324#define RUN_SETUP_GENTLY        (1<<1)
 325#define USE_PAGER               (1<<2)
 326/*
 327 * require working tree to be present -- anything uses this needs
 328 * RUN_SETUP for reading from the configuration file.
 329 */
 330#define NEED_WORK_TREE          (1<<3)
 331#define SUPPORT_SUPER_PREFIX    (1<<4)
 332
 333struct cmd_struct {
 334        const char *cmd;
 335        int (*fn)(int, const char **, const char *);
 336        int option;
 337};
 338
 339static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 340{
 341        int status, help;
 342        struct stat st;
 343        const char *prefix;
 344
 345        prefix = NULL;
 346        help = argc == 2 && !strcmp(argv[1], "-h");
 347        if (!help) {
 348                if (p->option & RUN_SETUP)
 349                        prefix = setup_git_directory();
 350                else if (p->option & RUN_SETUP_GENTLY) {
 351                        int nongit_ok;
 352                        prefix = setup_git_directory_gently(&nongit_ok);
 353                }
 354
 355                if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
 356                        use_pager = check_pager_config(p->cmd);
 357                if (use_pager == -1 && p->option & USE_PAGER)
 358                        use_pager = 1;
 359
 360                if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 361                    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 362                        trace_repo_setup(prefix);
 363        }
 364        commit_pager_choice();
 365
 366        if (!help && get_super_prefix()) {
 367                if (!(p->option & SUPPORT_SUPER_PREFIX))
 368                        die("%s doesn't support --super-prefix", p->cmd);
 369        }
 370
 371        if (!help && p->option & NEED_WORK_TREE)
 372                setup_work_tree();
 373
 374        trace_argv_printf(argv, "trace: built-in: git");
 375
 376        status = p->fn(argc, argv, prefix);
 377        if (status)
 378                return status;
 379
 380        /* Somebody closed stdout? */
 381        if (fstat(fileno(stdout), &st))
 382                return 0;
 383        /* Ignore write errors for pipes and sockets.. */
 384        if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 385                return 0;
 386
 387        /* Check for ENOSPC and EIO errors.. */
 388        if (fflush(stdout))
 389                die_errno("write failure on standard output");
 390        if (ferror(stdout))
 391                die("unknown write failure on standard output");
 392        if (fclose(stdout))
 393                die_errno("close failed on standard output");
 394        return 0;
 395}
 396
 397static struct cmd_struct commands[] = {
 398        { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 399        { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 400        { "annotate", cmd_annotate, RUN_SETUP },
 401        { "apply", cmd_apply, RUN_SETUP_GENTLY },
 402        { "archive", cmd_archive, RUN_SETUP_GENTLY },
 403        { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 404        { "blame", cmd_blame, RUN_SETUP },
 405        { "branch", cmd_branch, RUN_SETUP },
 406        { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 407        { "cat-file", cmd_cat_file, RUN_SETUP },
 408        { "check-attr", cmd_check_attr, RUN_SETUP },
 409        { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 410        { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 411        { "check-ref-format", cmd_check_ref_format },
 412        { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 413        { "checkout-index", cmd_checkout_index,
 414                RUN_SETUP | NEED_WORK_TREE},
 415        { "cherry", cmd_cherry, RUN_SETUP },
 416        { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 417        { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 418        { "clone", cmd_clone },
 419        { "column", cmd_column, RUN_SETUP_GENTLY },
 420        { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 421        { "commit-tree", cmd_commit_tree, RUN_SETUP },
 422        { "config", cmd_config, RUN_SETUP_GENTLY },
 423        { "count-objects", cmd_count_objects, RUN_SETUP },
 424        { "credential", cmd_credential, RUN_SETUP_GENTLY },
 425        { "describe", cmd_describe, RUN_SETUP },
 426        { "diff", cmd_diff },
 427        { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 428        { "diff-index", cmd_diff_index, RUN_SETUP },
 429        { "diff-tree", cmd_diff_tree, RUN_SETUP },
 430        { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 431        { "fast-export", cmd_fast_export, RUN_SETUP },
 432        { "fetch", cmd_fetch, RUN_SETUP },
 433        { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 434        { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 435        { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 436        { "format-patch", cmd_format_patch, RUN_SETUP },
 437        { "fsck", cmd_fsck, RUN_SETUP },
 438        { "fsck-objects", cmd_fsck, RUN_SETUP },
 439        { "gc", cmd_gc, RUN_SETUP },
 440        { "get-tar-commit-id", cmd_get_tar_commit_id },
 441        { "grep", cmd_grep, RUN_SETUP_GENTLY | SUPPORT_SUPER_PREFIX },
 442        { "hash-object", cmd_hash_object },
 443        { "help", cmd_help },
 444        { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 445        { "init", cmd_init_db },
 446        { "init-db", cmd_init_db },
 447        { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 448        { "log", cmd_log, RUN_SETUP },
 449        { "ls-files", cmd_ls_files, RUN_SETUP | SUPPORT_SUPER_PREFIX },
 450        { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 451        { "ls-tree", cmd_ls_tree, RUN_SETUP },
 452        { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 453        { "mailsplit", cmd_mailsplit },
 454        { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 455        { "merge-base", cmd_merge_base, RUN_SETUP },
 456        { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 457        { "merge-index", cmd_merge_index, RUN_SETUP },
 458        { "merge-ours", cmd_merge_ours, RUN_SETUP },
 459        { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 460        { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 461        { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 462        { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 463        { "merge-tree", cmd_merge_tree, RUN_SETUP },
 464        { "mktag", cmd_mktag, RUN_SETUP },
 465        { "mktree", cmd_mktree, RUN_SETUP },
 466        { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 467        { "name-rev", cmd_name_rev, RUN_SETUP },
 468        { "notes", cmd_notes, RUN_SETUP },
 469        { "pack-objects", cmd_pack_objects, RUN_SETUP },
 470        { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 471        { "pack-refs", cmd_pack_refs, RUN_SETUP },
 472        { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
 473        { "pickaxe", cmd_blame, RUN_SETUP },
 474        { "prune", cmd_prune, RUN_SETUP },
 475        { "prune-packed", cmd_prune_packed, RUN_SETUP },
 476        { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 477        { "push", cmd_push, RUN_SETUP },
 478        { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 479        { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 480        { "receive-pack", cmd_receive_pack },
 481        { "reflog", cmd_reflog, RUN_SETUP },
 482        { "remote", cmd_remote, RUN_SETUP },
 483        { "remote-ext", cmd_remote_ext },
 484        { "remote-fd", cmd_remote_fd },
 485        { "repack", cmd_repack, RUN_SETUP },
 486        { "replace", cmd_replace, RUN_SETUP },
 487        { "rerere", cmd_rerere, RUN_SETUP },
 488        { "reset", cmd_reset, RUN_SETUP },
 489        { "rev-list", cmd_rev_list, RUN_SETUP },
 490        { "rev-parse", cmd_rev_parse },
 491        { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 492        { "rm", cmd_rm, RUN_SETUP },
 493        { "send-pack", cmd_send_pack, RUN_SETUP },
 494        { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 495        { "show", cmd_show, RUN_SETUP },
 496        { "show-branch", cmd_show_branch, RUN_SETUP },
 497        { "show-ref", cmd_show_ref, RUN_SETUP },
 498        { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 499        { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 500        { "stripspace", cmd_stripspace },
 501        { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 502        { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 503        { "tag", cmd_tag, RUN_SETUP },
 504        { "unpack-file", cmd_unpack_file, RUN_SETUP },
 505        { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 506        { "update-index", cmd_update_index, RUN_SETUP },
 507        { "update-ref", cmd_update_ref, RUN_SETUP },
 508        { "update-server-info", cmd_update_server_info, RUN_SETUP },
 509        { "upload-archive", cmd_upload_archive },
 510        { "upload-archive--writer", cmd_upload_archive_writer },
 511        { "var", cmd_var, RUN_SETUP_GENTLY },
 512        { "verify-commit", cmd_verify_commit, RUN_SETUP },
 513        { "verify-pack", cmd_verify_pack },
 514        { "verify-tag", cmd_verify_tag, RUN_SETUP },
 515        { "version", cmd_version },
 516        { "whatchanged", cmd_whatchanged, RUN_SETUP },
 517        { "worktree", cmd_worktree, RUN_SETUP },
 518        { "write-tree", cmd_write_tree, RUN_SETUP },
 519};
 520
 521static struct cmd_struct *get_builtin(const char *s)
 522{
 523        int i;
 524        for (i = 0; i < ARRAY_SIZE(commands); i++) {
 525                struct cmd_struct *p = commands + i;
 526                if (!strcmp(s, p->cmd))
 527                        return p;
 528        }
 529        return NULL;
 530}
 531
 532int is_builtin(const char *s)
 533{
 534        return !!get_builtin(s);
 535}
 536
 537static void list_builtins(void)
 538{
 539        int i;
 540        for (i = 0; i < ARRAY_SIZE(commands); i++)
 541                printf("%s\n", commands[i].cmd);
 542}
 543
 544#ifdef STRIP_EXTENSION
 545static void strip_extension(const char **argv)
 546{
 547        size_t len;
 548
 549        if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 550                argv[0] = xmemdupz(argv[0], len);
 551}
 552#else
 553#define strip_extension(cmd)
 554#endif
 555
 556static void handle_builtin(int argc, const char **argv)
 557{
 558        struct argv_array args = ARGV_ARRAY_INIT;
 559        const char *cmd;
 560        struct cmd_struct *builtin;
 561
 562        strip_extension(argv);
 563        cmd = argv[0];
 564
 565        /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 566        if (argc > 1 && !strcmp(argv[1], "--help")) {
 567                int i;
 568
 569                argv[1] = argv[0];
 570                argv[0] = cmd = "help";
 571
 572                for (i = 0; i < argc; i++) {
 573                        argv_array_push(&args, argv[i]);
 574                        if (!i)
 575                                argv_array_push(&args, "--exclude-guides");
 576                }
 577
 578                argc++;
 579                argv = args.argv;
 580        }
 581
 582        builtin = get_builtin(cmd);
 583        if (builtin)
 584                exit(run_builtin(builtin, argc, argv));
 585        argv_array_clear(&args);
 586}
 587
 588static void execv_dashed_external(const char **argv)
 589{
 590        struct child_process cmd = CHILD_PROCESS_INIT;
 591        int status;
 592
 593        if (get_super_prefix())
 594                die("%s doesn't support --super-prefix", argv[0]);
 595
 596        if (use_pager == -1)
 597                use_pager = check_pager_config(argv[0]);
 598        commit_pager_choice();
 599
 600        argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 601        argv_array_pushv(&cmd.args, argv + 1);
 602        cmd.clean_on_exit = 1;
 603        cmd.wait_after_clean = 1;
 604        cmd.silent_exec_failure = 1;
 605
 606        trace_argv_printf(cmd.args.argv, "trace: exec:");
 607
 608        /*
 609         * If we fail because the command is not found, it is
 610         * OK to return. Otherwise, we just pass along the status code,
 611         * or our usual generic code if we were not even able to exec
 612         * the program.
 613         */
 614        status = run_command(&cmd);
 615        if (status >= 0)
 616                exit(status);
 617        else if (errno != ENOENT)
 618                exit(128);
 619}
 620
 621static int run_argv(int *argcp, const char ***argv)
 622{
 623        int done_alias = 0;
 624
 625        while (1) {
 626                /*
 627                 * If we tried alias and futzed with our environment,
 628                 * it no longer is safe to invoke builtins directly in
 629                 * general.  We have to spawn them as dashed externals.
 630                 *
 631                 * NEEDSWORK: if we can figure out cases
 632                 * where it is safe to do, we can avoid spawning a new
 633                 * process.
 634                 */
 635                if (!done_alias)
 636                        handle_builtin(*argcp, *argv);
 637
 638                /* .. then try the external ones */
 639                execv_dashed_external(*argv);
 640
 641                /* It could be an alias -- this works around the insanity
 642                 * of overriding "git log" with "git show" by having
 643                 * alias.log = show
 644                 */
 645                if (done_alias)
 646                        break;
 647                if (!handle_alias(argcp, argv))
 648                        break;
 649                done_alias = 1;
 650        }
 651
 652        return done_alias;
 653}
 654
 655int cmd_main(int argc, const char **argv)
 656{
 657        const char *cmd;
 658        int done_help = 0;
 659
 660        cmd = argv[0];
 661        if (!cmd)
 662                cmd = "git-help";
 663        else {
 664                const char *slash = find_last_dir_sep(cmd);
 665                if (slash)
 666                        cmd = slash + 1;
 667        }
 668
 669        trace_command_performance(argv);
 670
 671        /*
 672         * "git-xxxx" is the same as "git xxxx", but we obviously:
 673         *
 674         *  - cannot take flags in between the "git" and the "xxxx".
 675         *  - cannot execute it externally (since it would just do
 676         *    the same thing over again)
 677         *
 678         * So we just directly call the builtin handler, and die if
 679         * that one cannot handle it.
 680         */
 681        if (skip_prefix(cmd, "git-", &cmd)) {
 682                argv[0] = cmd;
 683                handle_builtin(argc, argv);
 684                die("cannot handle %s as a builtin", cmd);
 685        }
 686
 687        /* Look for flags.. */
 688        argv++;
 689        argc--;
 690        handle_options(&argv, &argc, NULL);
 691        if (argc > 0) {
 692                /* translate --help and --version into commands */
 693                skip_prefix(argv[0], "--", &argv[0]);
 694        } else {
 695                /* The user didn't specify a command; give them help */
 696                commit_pager_choice();
 697                printf("usage: %s\n\n", git_usage_string);
 698                list_common_cmds_help();
 699                printf("\n%s\n", _(git_more_info_string));
 700                exit(1);
 701        }
 702        cmd = argv[0];
 703
 704        /*
 705         * We use PATH to find git commands, but we prepend some higher
 706         * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 707         * environment, and the $(gitexecdir) from the Makefile at build
 708         * time.
 709         */
 710        setup_path();
 711
 712        while (1) {
 713                int was_alias = run_argv(&argc, &argv);
 714                if (errno != ENOENT)
 715                        break;
 716                if (was_alias) {
 717                        fprintf(stderr, "Expansion of alias '%s' failed; "
 718                                "'%s' is not a git command\n",
 719                                cmd, argv[0]);
 720                        exit(1);
 721                }
 722                if (!done_help) {
 723                        cmd = argv[0] = help_unknown_cmd(cmd);
 724                        done_help = 1;
 725                } else
 726                        break;
 727        }
 728
 729        fprintf(stderr, "Failed to run command '%s': %s\n",
 730                cmd, strerror(errno));
 731
 732        return 1;
 733}