git.c

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