git.c

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