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         N_("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 list_builtins(void);
  22
  23 static void commit_pager_choice(void) {
  24         switch (use_pager) {
  25         case 0:
  26                 setenv("GIT_PAGER", "cat", 1);
  27                 break;
  28         case 1:
  29                 setup_pager();
  30                 break;
  31         default:
  32                 break;
  33         }
  34 }
  35
  36 void setup_auto_pager(const char *cmd, int def)
  37 {
  38         if (use_pager != -1 || pager_in_use())
  39                 return;
  40         use_pager = check_pager_config(cmd);
  41         if (use_pager == -1)
  42                 use_pager = def;
  43         commit_pager_choice();
  44 }
  45
  46 static int handle_options(const char ***argv, int *argc, int *envchanged)
  47 {
  48         const char **orig_argv = *argv;
  49
  50         while (*argc > 0) {
  51                 const char *cmd = (*argv)[0];
  52                 if (cmd[0] != '-')
  53                         break;
  54
  55                 /*
  56                  * For legacy reasons, the "version" and "help"
  57                  * commands can be written with "--" prepended
  58                  * to make them look like flags.
  59                  */
  60                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  61                         break;
  62
  63                 /*
  64                  * Check remaining flags.
  65                  */
  66                 if (skip_prefix(cmd, "--exec-path", &cmd)) {
  67                         if (*cmd == '=')
  68                                 git_set_argv_exec_path(cmd + 1);
  69                         else {
  70                                 puts(git_exec_path());
  71                                 exit(0);
  72                         }
  73                 } else if (!strcmp(cmd, "--html-path")) {
  74                         puts(system_path(GIT_HTML_PATH));
  75                         exit(0);
  76                 } else if (!strcmp(cmd, "--man-path")) {
  77                         puts(system_path(GIT_MAN_PATH));
  78                         exit(0);
  79                 } else if (!strcmp(cmd, "--info-path")) {
  80                         puts(system_path(GIT_INFO_PATH));
  81                         exit(0);
  82                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  83                         use_pager = 1;
  84                 } else if (!strcmp(cmd, "--no-pager")) {
  85                         use_pager = 0;
  86                         if (envchanged)
  87                                 *envchanged = 1;
  88                 } else if (!strcmp(cmd, "--no-replace-objects")) {
  89                         check_replace_refs = 0;
  90                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  91                         if (envchanged)
  92                                 *envchanged = 1;
  93                 } else if (!strcmp(cmd, "--git-dir")) {
  94                         if (*argc < 2) {
  95                                 fprintf(stderr, _("no directory given for --git-dir\n" ));
  96                                 usage(git_usage_string);
  97                         }
  98                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
  99                         if (envchanged)
 100                                 *envchanged = 1;
 101                         (*argv)++;
 102                         (*argc)--;
 103                 } else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
 104                         setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
 105                         if (envchanged)
 106                                 *envchanged = 1;
 107                 } else if (!strcmp(cmd, "--namespace")) {
 108                         if (*argc < 2) {
 109                                 fprintf(stderr, _("no namespace given for --namespace\n" ));
 110                                 usage(git_usage_string);
 111                         }
 112                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 113                         if (envchanged)
 114                                 *envchanged = 1;
 115                         (*argv)++;
 116                         (*argc)--;
 117                 } else if (skip_prefix(cmd, "--namespace=", &cmd)) {
 118                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
 119                         if (envchanged)
 120                                 *envchanged = 1;
 121                 } else if (!strcmp(cmd, "--work-tree")) {
 122                         if (*argc < 2) {
 123                                 fprintf(stderr, _("no directory given for --work-tree\n" ));
 124                                 usage(git_usage_string);
 125                         }
 126                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 127                         if (envchanged)
 128                                 *envchanged = 1;
 129                         (*argv)++;
 130                         (*argc)--;
 131                 } else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
 132                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
 133                         if (envchanged)
 134                                 *envchanged = 1;
 135                 } else if (!strcmp(cmd, "--super-prefix")) {
 136                         if (*argc < 2) {
 137                                 fprintf(stderr, _("no prefix given for --super-prefix\n" ));
 138                                 usage(git_usage_string);
 139                         }
 140                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
 141                         if (envchanged)
 142                                 *envchanged = 1;
 143                         (*argv)++;
 144                         (*argc)--;
 145                 } else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
 146                         setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
 147                         if (envchanged)
 148                                 *envchanged = 1;
 149                 } else if (!strcmp(cmd, "--bare")) {
 150                         char *cwd = xgetcwd();
 151                         is_bare_repository_cfg = 1;
 152                         setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
 153                         free(cwd);
 154                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 155                         if (envchanged)
 156                                 *envchanged = 1;
 157                 } else if (!strcmp(cmd, "-c")) {
 158                         if (*argc < 2) {
 159                                 fprintf(stderr, _("-c expects a configuration string\n" ));
 160                                 usage(git_usage_string);
 161                         }
 162                         git_config_push_parameter((*argv)[1]);
 163                         (*argv)++;
 164                         (*argc)--;
 165                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 166                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 167                         if (envchanged)
 168                                 *envchanged = 1;
 169                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 170                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 171                         if (envchanged)
 172                                 *envchanged = 1;
 173                 } else if (!strcmp(cmd, "--glob-pathspecs")) {
 174                         setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 175                         if (envchanged)
 176                                 *envchanged = 1;
 177                 } else if (!strcmp(cmd, "--noglob-pathspecs")) {
 178                         setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
 179                         if (envchanged)
 180                                 *envchanged = 1;
 181                 } else if (!strcmp(cmd, "--icase-pathspecs")) {
 182                         setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
 183                         if (envchanged)
 184                                 *envchanged = 1;
 185                 } else if (!strcmp(cmd, "--no-optional-locks")) {
 186                         setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
 187                         if (envchanged)
 188                                 *envchanged = 1;
 189                 } else if (!strcmp(cmd, "--shallow-file")) {
 190                         (*argv)++;
 191                         (*argc)--;
 192                         set_alternate_shallow_file((*argv)[0], 1);
 193                         if (envchanged)
 194                                 *envchanged = 1;
 195                 } else if (!strcmp(cmd, "-C")) {
 196                         if (*argc < 2) {
 197                                 fprintf(stderr, _("no directory given for -C\n" ));
 198                                 usage(git_usage_string);
 199                         }
 200                         if ((*argv)[1][0]) {
 201                                 if (chdir((*argv)[1]))
 202                                         die_errno("cannot change to '%s'", (*argv)[1]);
 203                                 if (envchanged)
 204                                         *envchanged = 1;
 205                         }
 206                         (*argv)++;
 207                         (*argc)--;
 208                 } else if (!strcmp(cmd, "--list-builtins")) {
 209                         list_builtins();
 210                         exit(0);
 211                 } else {
 212                         fprintf(stderr, _("unknown option: %s\n"), cmd);
 213                         usage(git_usage_string);
 214                 }
 215
 216                 (*argv)++;
 217                 (*argc)--;
 218         }
 219         return (*argv) - orig_argv;
 220 }
 221
 222 static int handle_alias(int *argcp, const char ***argv)
 223 {
 224         int envchanged = 0, ret = 0, saved_errno = errno;
 225         int count, option_count;
 226         const char **new_argv;
 227         const char *alias_command;
 228         char *alias_string;
 229
 230         alias_command = (*argv)[0];
 231         alias_string = alias_lookup(alias_command);
 232         if (alias_string) {
 233                 if (alias_string[0] == '!') {
 234                         struct child_process child = CHILD_PROCESS_INIT;
 235                         int nongit_ok;
 236
 237                         /* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
 238                         setup_git_directory_gently(&nongit_ok);
 239
 240                         commit_pager_choice();
 241
 242                         child.use_shell = 1;
 243                         argv_array_push(&child.args, alias_string + 1);
 244                         argv_array_pushv(&child.args, (*argv) + 1);
 245
 246                         ret = run_command(&child);
 247                         if (ret >= 0)   /* normal exit */
 248                                 exit(ret);
 249
 250                         die_errno("while expanding alias '%s': '%s'",
 251                             alias_command, alias_string + 1);
 252                 }
 253                 count = split_cmdline(alias_string, &new_argv);
 254                 if (count < 0)
 255                         die("Bad alias.%s string: %s", alias_command,
 256                             split_cmdline_strerror(count));
 257                 option_count = handle_options(&new_argv, &count, &envchanged);
 258                 if (envchanged)
 259                         die("alias '%s' changes environment variables.\n"
 260                                  "You can use '!git' in the alias to do this",
 261                                  alias_command);
 262                 memmove(new_argv - option_count, new_argv,
 263                                 count * sizeof(char *));
 264                 new_argv -= option_count;
 265
 266                 if (count < 1)
 267                         die("empty alias for %s", alias_command);
 268
 269                 if (!strcmp(alias_command, new_argv[0]))
 270                         die("recursive alias: %s", alias_command);
 271
 272                 trace_argv_printf(new_argv,
 273                                   "trace: alias expansion: %s =>",
 274                                   alias_command);
 275
 276                 REALLOC_ARRAY(new_argv, count + *argcp);
 277                 /* insert after command name */
 278                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 279
 280                 *argv = new_argv;
 281                 *argcp += count - 1;
 282
 283                 ret = 1;
 284         }
 285
 286         errno = saved_errno;
 287
 288         return ret;
 289 }
 290
 291 #define RUN_SETUP               (1<<0)
 292 #define RUN_SETUP_GENTLY        (1<<1)
 293 #define USE_PAGER               (1<<2)
 294 /*
 295  * require working tree to be present -- anything uses this needs
 296  * RUN_SETUP for reading from the configuration file.
 297  */
 298 #define NEED_WORK_TREE          (1<<3)
 299 #define SUPPORT_SUPER_PREFIX    (1<<4)
 300 #define DELAY_PAGER_CONFIG      (1<<5)
 301
 302 struct cmd_struct {
 303         const char *cmd;
 304         int (*fn)(int, const char **, const char *);
 305         int option;
 306 };
 307
 308 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 309 {
 310         int status, help;
 311         struct stat st;
 312         const char *prefix;
 313
 314         prefix = NULL;
 315         help = argc == 2 && !strcmp(argv[1], "-h");
 316         if (!help) {
 317                 if (p->option & RUN_SETUP)
 318                         prefix = setup_git_directory();
 319                 else if (p->option & RUN_SETUP_GENTLY) {
 320                         int nongit_ok;
 321                         prefix = setup_git_directory_gently(&nongit_ok);
 322                 }
 323
 324                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
 325                     !(p->option & DELAY_PAGER_CONFIG))
 326                         use_pager = check_pager_config(p->cmd);
 327                 if (use_pager == -1 && p->option & USE_PAGER)
 328                         use_pager = 1;
 329
 330                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 331                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 332                         trace_repo_setup(prefix);
 333         }
 334         commit_pager_choice();
 335
 336         if (!help && get_super_prefix()) {
 337                 if (!(p->option & SUPPORT_SUPER_PREFIX))
 338                         die("%s doesn't support --super-prefix", p->cmd);
 339         }
 340
 341         if (!help && p->option & NEED_WORK_TREE)
 342                 setup_work_tree();
 343
 344         trace_argv_printf(argv, "trace: built-in: git");
 345
 346         status = p->fn(argc, argv, prefix);
 347         if (status)
 348                 return status;
 349
 350         /* Somebody closed stdout? */
 351         if (fstat(fileno(stdout), &st))
 352                 return 0;
 353         /* Ignore write errors for pipes and sockets.. */
 354         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 355                 return 0;
 356
 357         /* Check for ENOSPC and EIO errors.. */
 358         if (fflush(stdout))
 359                 die_errno("write failure on standard output");
 360         if (ferror(stdout))
 361                 die("unknown write failure on standard output");
 362         if (fclose(stdout))
 363                 die_errno("close failed on standard output");
 364         return 0;
 365 }
 366
 367 static struct cmd_struct commands[] = {
 368         { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 369         { "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
 370         { "annotate", cmd_annotate, RUN_SETUP },
 371         { "apply", cmd_apply, RUN_SETUP_GENTLY },
 372         { "archive", cmd_archive, RUN_SETUP_GENTLY },
 373         { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 374         { "blame", cmd_blame, RUN_SETUP },
 375         { "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
 376         { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 377         { "cat-file", cmd_cat_file, RUN_SETUP },
 378         { "check-attr", cmd_check_attr, RUN_SETUP },
 379         { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 380         { "check-mailmap", cmd_check_mailmap, RUN_SETUP },
 381         { "check-ref-format", cmd_check_ref_format },
 382         { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 383         { "checkout-index", cmd_checkout_index,
 384                 RUN_SETUP | NEED_WORK_TREE},
 385         { "cherry", cmd_cherry, RUN_SETUP },
 386         { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 387         { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 388         { "clone", cmd_clone },
 389         { "column", cmd_column, RUN_SETUP_GENTLY },
 390         { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 391         { "commit-tree", cmd_commit_tree, RUN_SETUP },
 392         { "config", cmd_config, RUN_SETUP_GENTLY },
 393         { "count-objects", cmd_count_objects, RUN_SETUP },
 394         { "credential", cmd_credential, RUN_SETUP_GENTLY },
 395         { "describe", cmd_describe, RUN_SETUP },
 396         { "diff", cmd_diff },
 397         { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 398         { "diff-index", cmd_diff_index, RUN_SETUP },
 399         { "diff-tree", cmd_diff_tree, RUN_SETUP },
 400         { "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
 401         { "fast-export", cmd_fast_export, RUN_SETUP },
 402         { "fetch", cmd_fetch, RUN_SETUP },
 403         { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 404         { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 405         { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 406         { "format-patch", cmd_format_patch, RUN_SETUP },
 407         { "fsck", cmd_fsck, RUN_SETUP },
 408         { "fsck-objects", cmd_fsck, RUN_SETUP },
 409         { "gc", cmd_gc, RUN_SETUP },
 410         { "get-tar-commit-id", cmd_get_tar_commit_id },
 411         { "grep", cmd_grep, RUN_SETUP_GENTLY },
 412         { "hash-object", cmd_hash_object },
 413         { "help", cmd_help },
 414         { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 415         { "init", cmd_init_db },
 416         { "init-db", cmd_init_db },
 417         { "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
 418         { "log", cmd_log, RUN_SETUP },
 419         { "ls-files", cmd_ls_files, RUN_SETUP },
 420         { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 421         { "ls-tree", cmd_ls_tree, RUN_SETUP },
 422         { "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY },
 423         { "mailsplit", cmd_mailsplit },
 424         { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 425         { "merge-base", cmd_merge_base, RUN_SETUP },
 426         { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 427         { "merge-index", cmd_merge_index, RUN_SETUP },
 428         { "merge-ours", cmd_merge_ours, RUN_SETUP },
 429         { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 430         { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 431         { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 432         { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 433         { "merge-tree", cmd_merge_tree, RUN_SETUP },
 434         { "mktag", cmd_mktag, RUN_SETUP },
 435         { "mktree", cmd_mktree, RUN_SETUP },
 436         { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 437         { "name-rev", cmd_name_rev, RUN_SETUP },
 438         { "notes", cmd_notes, RUN_SETUP },
 439         { "pack-objects", cmd_pack_objects, RUN_SETUP },
 440         { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 441         { "pack-refs", cmd_pack_refs, RUN_SETUP },
 442         { "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
 443         { "pickaxe", cmd_blame, RUN_SETUP },
 444         { "prune", cmd_prune, RUN_SETUP },
 445         { "prune-packed", cmd_prune_packed, RUN_SETUP },
 446         { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 447         { "push", cmd_push, RUN_SETUP },
 448         { "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 449         { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 450         { "receive-pack", cmd_receive_pack },
 451         { "reflog", cmd_reflog, RUN_SETUP },
 452         { "remote", cmd_remote, RUN_SETUP },
 453         { "remote-ext", cmd_remote_ext },
 454         { "remote-fd", cmd_remote_fd },
 455         { "repack", cmd_repack, RUN_SETUP },
 456         { "replace", cmd_replace, RUN_SETUP },
 457         { "rerere", cmd_rerere, RUN_SETUP },
 458         { "reset", cmd_reset, RUN_SETUP },
 459         { "rev-list", cmd_rev_list, RUN_SETUP },
 460         { "rev-parse", cmd_rev_parse },
 461         { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 462         { "rm", cmd_rm, RUN_SETUP },
 463         { "send-pack", cmd_send_pack, RUN_SETUP },
 464         { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 465         { "show", cmd_show, RUN_SETUP },
 466         { "show-branch", cmd_show_branch, RUN_SETUP },
 467         { "show-ref", cmd_show_ref, RUN_SETUP },
 468         { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 469         { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 470         { "stripspace", cmd_stripspace },
 471         { "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 472         { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 473         { "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 474         { "unpack-file", cmd_unpack_file, RUN_SETUP },
 475         { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 476         { "update-index", cmd_update_index, RUN_SETUP },
 477         { "update-ref", cmd_update_ref, RUN_SETUP },
 478         { "update-server-info", cmd_update_server_info, RUN_SETUP },
 479         { "upload-archive", cmd_upload_archive },
 480         { "upload-archive--writer", cmd_upload_archive_writer },
 481         { "var", cmd_var, RUN_SETUP_GENTLY },
 482         { "verify-commit", cmd_verify_commit, RUN_SETUP },
 483         { "verify-pack", cmd_verify_pack },
 484         { "verify-tag", cmd_verify_tag, RUN_SETUP },
 485         { "version", cmd_version },
 486         { "whatchanged", cmd_whatchanged, RUN_SETUP },
 487         { "worktree", cmd_worktree, RUN_SETUP },
 488         { "write-tree", cmd_write_tree, RUN_SETUP },
 489 };
 490
 491 static struct cmd_struct *get_builtin(const char *s)
 492 {
 493         int i;
 494         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 495                 struct cmd_struct *p = commands + i;
 496                 if (!strcmp(s, p->cmd))
 497                         return p;
 498         }
 499         return NULL;
 500 }
 501
 502 int is_builtin(const char *s)
 503 {
 504         return !!get_builtin(s);
 505 }
 506
 507 static void list_builtins(void)
 508 {
 509         int i;
 510         for (i = 0; i < ARRAY_SIZE(commands); i++)
 511                 printf("%s\n", commands[i].cmd);
 512 }
 513
 514 #ifdef STRIP_EXTENSION
 515 static void strip_extension(const char **argv)
 516 {
 517         size_t len;
 518
 519         if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
 520                 argv[0] = xmemdupz(argv[0], len);
 521 }
 522 #else
 523 #define strip_extension(cmd)
 524 #endif
 525
 526 static void handle_builtin(int argc, const char **argv)
 527 {
 528         struct argv_array args = ARGV_ARRAY_INIT;
 529         const char *cmd;
 530         struct cmd_struct *builtin;
 531
 532         strip_extension(argv);
 533         cmd = argv[0];
 534
 535         /* Turn "git cmd --help" into "git help --exclude-guides cmd" */
 536         if (argc > 1 && !strcmp(argv[1], "--help")) {
 537                 int i;
 538
 539                 argv[1] = argv[0];
 540                 argv[0] = cmd = "help";
 541
 542                 for (i = 0; i < argc; i++) {
 543                         argv_array_push(&args, argv[i]);
 544                         if (!i)
 545                                 argv_array_push(&args, "--exclude-guides");
 546                 }
 547
 548                 argc++;
 549                 argv = args.argv;
 550         }
 551
 552         builtin = get_builtin(cmd);
 553         if (builtin)
 554                 exit(run_builtin(builtin, argc, argv));
 555         argv_array_clear(&args);
 556 }
 557
 558 static void execv_dashed_external(const char **argv)
 559 {
 560         struct child_process cmd = CHILD_PROCESS_INIT;
 561         int status;
 562
 563         if (get_super_prefix())
 564                 die("%s doesn't support --super-prefix", argv[0]);
 565
 566         if (use_pager == -1 && !is_builtin(argv[0]))
 567                 use_pager = check_pager_config(argv[0]);
 568         commit_pager_choice();
 569
 570         argv_array_pushf(&cmd.args, "git-%s", argv[0]);
 571         argv_array_pushv(&cmd.args, argv + 1);
 572         cmd.clean_on_exit = 1;
 573         cmd.wait_after_clean = 1;
 574         cmd.silent_exec_failure = 1;
 575
 576         trace_argv_printf(cmd.args.argv, "trace: exec:");
 577
 578         /*
 579          * If we fail because the command is not found, it is
 580          * OK to return. Otherwise, we just pass along the status code,
 581          * or our usual generic code if we were not even able to exec
 582          * the program.
 583          */
 584         status = run_command(&cmd);
 585         if (status >= 0)
 586                 exit(status);
 587         else if (errno != ENOENT)
 588                 exit(128);
 589 }
 590
 591 static int run_argv(int *argcp, const char ***argv)
 592 {
 593         int done_alias = 0;
 594
 595         while (1) {
 596                 /*
 597                  * If we tried alias and futzed with our environment,
 598                  * it no longer is safe to invoke builtins directly in
 599                  * general.  We have to spawn them as dashed externals.
 600                  *
 601                  * NEEDSWORK: if we can figure out cases
 602                  * where it is safe to do, we can avoid spawning a new
 603                  * process.
 604                  */
 605                 if (!done_alias)
 606                         handle_builtin(*argcp, *argv);
 607
 608                 /* .. then try the external ones */
 609                 execv_dashed_external(*argv);
 610
 611                 /* It could be an alias -- this works around the insanity
 612                  * of overriding "git log" with "git show" by having
 613                  * alias.log = show
 614                  */
 615                 if (done_alias)
 616                         break;
 617                 if (!handle_alias(argcp, argv))
 618                         break;
 619                 done_alias = 1;
 620         }
 621
 622         return done_alias;
 623 }
 624
 625 int cmd_main(int argc, const char **argv)
 626 {
 627         const char *cmd;
 628         int done_help = 0;
 629
 630         cmd = argv[0];
 631         if (!cmd)
 632                 cmd = "git-help";
 633         else {
 634                 const char *slash = find_last_dir_sep(cmd);
 635                 if (slash)
 636                         cmd = slash + 1;
 637         }
 638
 639         trace_command_performance(argv);
 640
 641         /*
 642          * "git-xxxx" is the same as "git xxxx", but we obviously:
 643          *
 644          *  - cannot take flags in between the "git" and the "xxxx".
 645          *  - cannot execute it externally (since it would just do
 646          *    the same thing over again)
 647          *
 648          * So we just directly call the builtin handler, and die if
 649          * that one cannot handle it.
 650          */
 651         if (skip_prefix(cmd, "git-", &cmd)) {
 652                 argv[0] = cmd;
 653                 handle_builtin(argc, argv);
 654                 die("cannot handle %s as a builtin", cmd);
 655         }
 656
 657         /* Look for flags.. */
 658         argv++;
 659         argc--;
 660         handle_options(&argv, &argc, NULL);
 661         if (argc > 0) {
 662                 /* translate --help and --version into commands */
 663                 skip_prefix(argv[0], "--", &argv[0]);
 664         } else {
 665                 /* The user didn't specify a command; give them help */
 666                 commit_pager_choice();
 667                 printf("usage: %s\n\n", git_usage_string);
 668                 list_common_cmds_help();
 669                 printf("\n%s\n", _(git_more_info_string));
 670                 exit(1);
 671         }
 672         cmd = argv[0];
 673
 674         /*
 675          * We use PATH to find git commands, but we prepend some higher
 676          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 677          * environment, and the $(gitexecdir) from the Makefile at build
 678          * time.
 679          */
 680         setup_path();
 681
 682         while (1) {
 683                 int was_alias = run_argv(&argc, &argv);
 684                 if (errno != ENOENT)
 685                         break;
 686                 if (was_alias) {
 687                         fprintf(stderr, _("expansion of alias '%s' failed; "
 688                                           "'%s' is not a git command\n"),
 689                                 cmd, argv[0]);
 690                         exit(1);
 691                 }
 692                 if (!done_help) {
 693                         cmd = argv[0] = help_unknown_cmd(cmd);
 694                         done_help = 1;
 695                 } else
 696                         break;
 697         }
 698
 699         fprintf(stderr, _("failed to run command '%s': %s\n"),
 700                 cmd, strerror(errno));
 701
 702         return 1;
 703 }