git.oblomov.eu Git - git/blob - git.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "exec_cmd.h"
   4 #include "help.h"
   5 #include "quote.h"
   6 #include "run-command.h"
   7 #include "commit.h"
   8
   9 const char git_usage_string[] =
  10         "git [--version] [--help] [-c name=value]\n"
  11         "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
  12         "           [-p|--paginate|--no-pager] [--no-replace-objects] [--bare]\n"
  13         "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
  14         "           <command> [<args>]";
  15
  16 const char git_more_info_string[] =
  17         N_("'git help -a' and 'git help -g' lists available subcommands and some\n"
  18            "concept guides. See 'git help <command>' or 'git help <concept>'\n"
  19            "to read about a specific subcommand or concept.");
  20
  21 static struct startup_info git_startup_info;
  22 static int use_pager = -1;
  23
  24 static void commit_pager_choice(void) {
  25         switch (use_pager) {
  26         case 0:
  27                 setenv("GIT_PAGER", "cat", 1);
  28                 break;
  29         case 1:
  30                 setup_pager();
  31                 break;
  32         default:
  33                 break;
  34         }
  35 }
  36
  37 static int handle_options(const char ***argv, int *argc, int *envchanged)
  38 {
  39         const char **orig_argv = *argv;
  40
  41         while (*argc > 0) {
  42                 const char *cmd = (*argv)[0];
  43                 if (cmd[0] != '-')
  44                         break;
  45
  46                 /*
  47                  * For legacy reasons, the "version" and "help"
  48                  * commands can be written with "--" prepended
  49                  * to make them look like flags.
  50                  */
  51                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  52                         break;
  53
  54                 /*
  55                  * Check remaining flags.
  56                  */
  57                 if (!prefixcmp(cmd, "--exec-path")) {
  58                         cmd += 11;
  59                         if (*cmd == '=')
  60                                 git_set_argv_exec_path(cmd + 1);
  61                         else {
  62                                 puts(git_exec_path());
  63                                 exit(0);
  64                         }
  65                 } else if (!strcmp(cmd, "--html-path")) {
  66                         puts(system_path(GIT_HTML_PATH));
  67                         exit(0);
  68                 } else if (!strcmp(cmd, "--man-path")) {
  69                         puts(system_path(GIT_MAN_PATH));
  70                         exit(0);
  71                 } else if (!strcmp(cmd, "--info-path")) {
  72                         puts(system_path(GIT_INFO_PATH));
  73                         exit(0);
  74                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
  75                         use_pager = 1;
  76                 } else if (!strcmp(cmd, "--no-pager")) {
  77                         use_pager = 0;
  78                         if (envchanged)
  79                                 *envchanged = 1;
  80                 } else if (!strcmp(cmd, "--no-replace-objects")) {
  81                         read_replace_refs = 0;
  82                         setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
  83                         if (envchanged)
  84                                 *envchanged = 1;
  85                 } else if (!strcmp(cmd, "--git-dir")) {
  86                         if (*argc < 2) {
  87                                 fprintf(stderr, "No directory given for --git-dir.\n" );
  88                                 usage(git_usage_string);
  89                         }
  90                         setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
  91                         if (envchanged)
  92                                 *envchanged = 1;
  93                         (*argv)++;
  94                         (*argc)--;
  95                 } else if (!prefixcmp(cmd, "--git-dir=")) {
  96                         setenv(GIT_DIR_ENVIRONMENT, cmd + 10, 1);
  97                         if (envchanged)
  98                                 *envchanged = 1;
  99                 } else if (!strcmp(cmd, "--namespace")) {
 100                         if (*argc < 2) {
 101                                 fprintf(stderr, "No namespace given for --namespace.\n" );
 102                                 usage(git_usage_string);
 103                         }
 104                         setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
 105                         if (envchanged)
 106                                 *envchanged = 1;
 107                         (*argv)++;
 108                         (*argc)--;
 109                 } else if (!prefixcmp(cmd, "--namespace=")) {
 110                         setenv(GIT_NAMESPACE_ENVIRONMENT, cmd + 12, 1);
 111                         if (envchanged)
 112                                 *envchanged = 1;
 113                 } else if (!strcmp(cmd, "--work-tree")) {
 114                         if (*argc < 2) {
 115                                 fprintf(stderr, "No directory given for --work-tree.\n" );
 116                                 usage(git_usage_string);
 117                         }
 118                         setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 119                         if (envchanged)
 120                                 *envchanged = 1;
 121                         (*argv)++;
 122                         (*argc)--;
 123                 } else if (!prefixcmp(cmd, "--work-tree=")) {
 124                         setenv(GIT_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
 125                         if (envchanged)
 126                                 *envchanged = 1;
 127                 } else if (!strcmp(cmd, "--bare")) {
 128                         static char git_dir[PATH_MAX+1];
 129                         is_bare_repository_cfg = 1;
 130                         setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir, sizeof(git_dir)), 0);
 131                         setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 132                         if (envchanged)
 133                                 *envchanged = 1;
 134                 } else if (!strcmp(cmd, "-c")) {
 135                         if (*argc < 2) {
 136                                 fprintf(stderr, "-c expects a configuration string\n" );
 137                                 usage(git_usage_string);
 138                         }
 139                         git_config_push_parameter((*argv)[1]);
 140                         (*argv)++;
 141                         (*argc)--;
 142                 } else if (!strcmp(cmd, "--literal-pathspecs")) {
 143                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
 144                         if (envchanged)
 145                                 *envchanged = 1;
 146                 } else if (!strcmp(cmd, "--no-literal-pathspecs")) {
 147                         setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
 148                         if (envchanged)
 149                                 *envchanged = 1;
 150                 } else if (!strcmp(cmd, "--shallow-file")) {
 151                         (*argv)++;
 152                         (*argc)--;
 153                         set_alternate_shallow_file((*argv)[0]);
 154                         if (envchanged)
 155                                 *envchanged = 1;
 156                 } else {
 157                         fprintf(stderr, "Unknown option: %s\n", cmd);
 158                         usage(git_usage_string);
 159                 }
 160
 161                 (*argv)++;
 162                 (*argc)--;
 163         }
 164         return (*argv) - orig_argv;
 165 }
 166
 167 static int handle_alias(int *argcp, const char ***argv)
 168 {
 169         int envchanged = 0, ret = 0, saved_errno = errno;
 170         const char *subdir;
 171         int count, option_count;
 172         const char **new_argv;
 173         const char *alias_command;
 174         char *alias_string;
 175         int unused_nongit;
 176
 177         subdir = setup_git_directory_gently(&unused_nongit);
 178
 179         alias_command = (*argv)[0];
 180         alias_string = alias_lookup(alias_command);
 181         if (alias_string) {
 182                 if (alias_string[0] == '!') {
 183                         const char **alias_argv;
 184                         int argc = *argcp, i;
 185
 186                         commit_pager_choice();
 187
 188                         /* build alias_argv */
 189                         alias_argv = xmalloc(sizeof(*alias_argv) * (argc + 1));
 190                         alias_argv[0] = alias_string + 1;
 191                         for (i = 1; i < argc; ++i)
 192                                 alias_argv[i] = (*argv)[i];
 193                         alias_argv[argc] = NULL;
 194
 195                         ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
 196                         if (ret >= 0)   /* normal exit */
 197                                 exit(ret);
 198
 199                         die_errno("While expanding alias '%s': '%s'",
 200                             alias_command, alias_string + 1);
 201                 }
 202                 count = split_cmdline(alias_string, &new_argv);
 203                 if (count < 0)
 204                         die("Bad alias.%s string: %s", alias_command,
 205                             split_cmdline_strerror(count));
 206                 option_count = handle_options(&new_argv, &count, &envchanged);
 207                 if (envchanged)
 208                         die("alias '%s' changes environment variables\n"
 209                                  "You can use '!git' in the alias to do this.",
 210                                  alias_command);
 211                 memmove(new_argv - option_count, new_argv,
 212                                 count * sizeof(char *));
 213                 new_argv -= option_count;
 214
 215                 if (count < 1)
 216                         die("empty alias for %s", alias_command);
 217
 218                 if (!strcmp(alias_command, new_argv[0]))
 219                         die("recursive alias: %s", alias_command);
 220
 221                 trace_argv_printf(new_argv,
 222                                   "trace: alias expansion: %s =>",
 223                                   alias_command);
 224
 225                 new_argv = xrealloc(new_argv, sizeof(char *) *
 226                                     (count + *argcp));
 227                 /* insert after command name */
 228                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 229
 230                 *argv = new_argv;
 231                 *argcp += count - 1;
 232
 233                 ret = 1;
 234         }
 235
 236         if (subdir && chdir(subdir))
 237                 die_errno("Cannot change to '%s'", subdir);
 238
 239         errno = saved_errno;
 240
 241         return ret;
 242 }
 243
 244 #define RUN_SETUP               (1<<0)
 245 #define RUN_SETUP_GENTLY        (1<<1)
 246 #define USE_PAGER               (1<<2)
 247 /*
 248  * require working tree to be present -- anything uses this needs
 249  * RUN_SETUP for reading from the configuration file.
 250  */
 251 #define NEED_WORK_TREE          (1<<3)
 252
 253 struct cmd_struct {
 254         const char *cmd;
 255         int (*fn)(int, const char **, const char *);
 256         int option;
 257 };
 258
 259 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 260 {
 261         int status, help;
 262         struct stat st;
 263         const char *prefix;
 264
 265         prefix = NULL;
 266         help = argc == 2 && !strcmp(argv[1], "-h");
 267         if (!help) {
 268                 if (p->option & RUN_SETUP)
 269                         prefix = setup_git_directory();
 270                 if (p->option & RUN_SETUP_GENTLY) {
 271                         int nongit_ok;
 272                         prefix = setup_git_directory_gently(&nongit_ok);
 273                 }
 274
 275                 if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
 276                         use_pager = check_pager_config(p->cmd);
 277                 if (use_pager == -1 && p->option & USE_PAGER)
 278                         use_pager = 1;
 279
 280                 if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
 281                     startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
 282                         trace_repo_setup(prefix);
 283         }
 284         commit_pager_choice();
 285
 286         if (!help && p->option & NEED_WORK_TREE)
 287                 setup_work_tree();
 288
 289         trace_argv_printf(argv, "trace: built-in: git");
 290
 291         status = p->fn(argc, argv, prefix);
 292         if (status)
 293                 return status;
 294
 295         /* Somebody closed stdout? */
 296         if (fstat(fileno(stdout), &st))
 297                 return 0;
 298         /* Ignore write errors for pipes and sockets.. */
 299         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 300                 return 0;
 301
 302         /* Check for ENOSPC and EIO errors.. */
 303         if (fflush(stdout))
 304                 die_errno("write failure on standard output");
 305         if (ferror(stdout))
 306                 die("unknown write failure on standard output");
 307         if (fclose(stdout))
 308                 die_errno("close failed on standard output");
 309         return 0;
 310 }
 311
 312 static void handle_internal_command(int argc, const char **argv)
 313 {
 314         const char *cmd = argv[0];
 315         static struct cmd_struct commands[] = {
 316                 { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 317                 { "annotate", cmd_annotate, RUN_SETUP },
 318                 { "apply", cmd_apply, RUN_SETUP_GENTLY },
 319                 { "archive", cmd_archive },
 320                 { "bisect--helper", cmd_bisect__helper, RUN_SETUP },
 321                 { "blame", cmd_blame, RUN_SETUP },
 322                 { "branch", cmd_branch, RUN_SETUP },
 323                 { "bundle", cmd_bundle, RUN_SETUP_GENTLY },
 324                 { "cat-file", cmd_cat_file, RUN_SETUP },
 325                 { "check-attr", cmd_check_attr, RUN_SETUP },
 326                 { "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
 327                 { "check-ref-format", cmd_check_ref_format },
 328                 { "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
 329                 { "checkout-index", cmd_checkout_index,
 330                         RUN_SETUP | NEED_WORK_TREE},
 331                 { "cherry", cmd_cherry, RUN_SETUP },
 332                 { "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
 333                 { "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
 334                 { "clone", cmd_clone },
 335                 { "column", cmd_column, RUN_SETUP_GENTLY },
 336                 { "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
 337                 { "commit-tree", cmd_commit_tree, RUN_SETUP },
 338                 { "config", cmd_config, RUN_SETUP_GENTLY },
 339                 { "count-objects", cmd_count_objects, RUN_SETUP },
 340                 { "credential", cmd_credential, RUN_SETUP_GENTLY },
 341                 { "describe", cmd_describe, RUN_SETUP },
 342                 { "diff", cmd_diff },
 343                 { "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 344                 { "diff-index", cmd_diff_index, RUN_SETUP },
 345                 { "diff-tree", cmd_diff_tree, RUN_SETUP },
 346                 { "fast-export", cmd_fast_export, RUN_SETUP },
 347                 { "fetch", cmd_fetch, RUN_SETUP },
 348                 { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
 349                 { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
 350                 { "for-each-ref", cmd_for_each_ref, RUN_SETUP },
 351                 { "format-patch", cmd_format_patch, RUN_SETUP },
 352                 { "fsck", cmd_fsck, RUN_SETUP },
 353                 { "fsck-objects", cmd_fsck, RUN_SETUP },
 354                 { "gc", cmd_gc, RUN_SETUP },
 355                 { "get-tar-commit-id", cmd_get_tar_commit_id },
 356                 { "grep", cmd_grep, RUN_SETUP_GENTLY },
 357                 { "hash-object", cmd_hash_object },
 358                 { "help", cmd_help },
 359                 { "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
 360                 { "init", cmd_init_db },
 361                 { "init-db", cmd_init_db },
 362                 { "log", cmd_log, RUN_SETUP },
 363                 { "ls-files", cmd_ls_files, RUN_SETUP },
 364                 { "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 365                 { "ls-tree", cmd_ls_tree, RUN_SETUP },
 366                 { "mailinfo", cmd_mailinfo },
 367                 { "mailsplit", cmd_mailsplit },
 368                 { "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
 369                 { "merge-base", cmd_merge_base, RUN_SETUP },
 370                 { "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
 371                 { "merge-index", cmd_merge_index, RUN_SETUP },
 372                 { "merge-ours", cmd_merge_ours, RUN_SETUP },
 373                 { "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 374                 { "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 375                 { "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 376                 { "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
 377                 { "merge-tree", cmd_merge_tree, RUN_SETUP },
 378                 { "mktag", cmd_mktag, RUN_SETUP },
 379                 { "mktree", cmd_mktree, RUN_SETUP },
 380                 { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 381                 { "name-rev", cmd_name_rev, RUN_SETUP },
 382                 { "notes", cmd_notes, RUN_SETUP },
 383                 { "pack-objects", cmd_pack_objects, RUN_SETUP },
 384                 { "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 385                 { "pack-refs", cmd_pack_refs, RUN_SETUP },
 386                 { "patch-id", cmd_patch_id },
 387                 { "peek-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
 388                 { "pickaxe", cmd_blame, RUN_SETUP },
 389                 { "prune", cmd_prune, RUN_SETUP },
 390                 { "prune-packed", cmd_prune_packed, RUN_SETUP },
 391                 { "push", cmd_push, RUN_SETUP },
 392                 { "read-tree", cmd_read_tree, RUN_SETUP },
 393                 { "receive-pack", cmd_receive_pack },
 394                 { "reflog", cmd_reflog, RUN_SETUP },
 395                 { "remote", cmd_remote, RUN_SETUP },
 396                 { "remote-ext", cmd_remote_ext },
 397                 { "remote-fd", cmd_remote_fd },
 398                 { "replace", cmd_replace, RUN_SETUP },
 399                 { "repo-config", cmd_repo_config, RUN_SETUP_GENTLY },
 400                 { "rerere", cmd_rerere, RUN_SETUP },
 401                 { "reset", cmd_reset, RUN_SETUP },
 402                 { "rev-list", cmd_rev_list, RUN_SETUP },
 403                 { "rev-parse", cmd_rev_parse },
 404                 { "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
 405                 { "rm", cmd_rm, RUN_SETUP },
 406                 { "send-pack", cmd_send_pack, RUN_SETUP },
 407                 { "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
 408                 { "show", cmd_show, RUN_SETUP },
 409                 { "show-branch", cmd_show_branch, RUN_SETUP },
 410                 { "show-ref", cmd_show_ref, RUN_SETUP },
 411                 { "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
 412                 { "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 413                 { "stripspace", cmd_stripspace },
 414                 { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 415                 { "tag", cmd_tag, RUN_SETUP },
 416                 { "tar-tree", cmd_tar_tree },
 417                 { "unpack-file", cmd_unpack_file, RUN_SETUP },
 418                 { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
 419                 { "update-index", cmd_update_index, RUN_SETUP },
 420                 { "update-ref", cmd_update_ref, RUN_SETUP },
 421                 { "update-server-info", cmd_update_server_info, RUN_SETUP },
 422                 { "upload-archive", cmd_upload_archive },
 423                 { "upload-archive--writer", cmd_upload_archive_writer },
 424                 { "var", cmd_var, RUN_SETUP_GENTLY },
 425                 { "verify-pack", cmd_verify_pack },
 426                 { "verify-tag", cmd_verify_tag, RUN_SETUP },
 427                 { "version", cmd_version },
 428                 { "whatchanged", cmd_whatchanged, RUN_SETUP },
 429                 { "write-tree", cmd_write_tree, RUN_SETUP },
 430         };
 431         int i;
 432         static const char ext[] = STRIP_EXTENSION;
 433
 434         if (sizeof(ext) > 1) {
 435                 i = strlen(argv[0]) - strlen(ext);
 436                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
 437                         char *argv0 = xstrdup(argv[0]);
 438                         argv[0] = cmd = argv0;
 439                         argv0[i] = '\0';
 440                 }
 441         }
 442
 443         /* Turn "git cmd --help" into "git help cmd" */
 444         if (argc > 1 && !strcmp(argv[1], "--help")) {
 445                 argv[1] = argv[0];
 446                 argv[0] = cmd = "help";
 447         }
 448
 449         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 450                 struct cmd_struct *p = commands+i;
 451                 if (strcmp(p->cmd, cmd))
 452                         continue;
 453                 exit(run_builtin(p, argc, argv));
 454         }
 455 }
 456
 457 static void execv_dashed_external(const char **argv)
 458 {
 459         struct strbuf cmd = STRBUF_INIT;
 460         const char *tmp;
 461         int status;
 462
 463         if (use_pager == -1)
 464                 use_pager = check_pager_config(argv[0]);
 465         commit_pager_choice();
 466
 467         strbuf_addf(&cmd, "git-%s", argv[0]);
 468
 469         /*
 470          * argv[0] must be the git command, but the argv array
 471          * belongs to the caller, and may be reused in
 472          * subsequent loop iterations. Save argv[0] and
 473          * restore it on error.
 474          */
 475         tmp = argv[0];
 476         argv[0] = cmd.buf;
 477
 478         trace_argv_printf(argv, "trace: exec:");
 479
 480         /*
 481          * if we fail because the command is not found, it is
 482          * OK to return. Otherwise, we just pass along the status code.
 483          */
 484         status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
 485         if (status >= 0 || errno != ENOENT)
 486                 exit(status);
 487
 488         argv[0] = tmp;
 489
 490         strbuf_release(&cmd);
 491 }
 492
 493 static int run_argv(int *argcp, const char ***argv)
 494 {
 495         int done_alias = 0;
 496
 497         while (1) {
 498                 /* See if it's an internal command */
 499                 handle_internal_command(*argcp, *argv);
 500
 501                 /* .. then try the external ones */
 502                 execv_dashed_external(*argv);
 503
 504                 /* It could be an alias -- this works around the insanity
 505                  * of overriding "git log" with "git show" by having
 506                  * alias.log = show
 507                  */
 508                 if (done_alias || !handle_alias(argcp, argv))
 509                         break;
 510                 done_alias = 1;
 511         }
 512
 513         return done_alias;
 514 }
 515
 516
 517 int main(int argc, char **av)
 518 {
 519         const char **argv = (const char **) av;
 520         const char *cmd;
 521
 522         startup_info = &git_startup_info;
 523
 524         cmd = git_extract_argv0_path(argv[0]);
 525         if (!cmd)
 526                 cmd = "git-help";
 527
 528         git_setup_gettext();
 529
 530         /*
 531          * "git-xxxx" is the same as "git xxxx", but we obviously:
 532          *
 533          *  - cannot take flags in between the "git" and the "xxxx".
 534          *  - cannot execute it externally (since it would just do
 535          *    the same thing over again)
 536          *
 537          * So we just directly call the internal command handler, and
 538          * die if that one cannot handle it.
 539          */
 540         if (!prefixcmp(cmd, "git-")) {
 541                 cmd += 4;
 542                 argv[0] = cmd;
 543                 handle_internal_command(argc, argv);
 544                 die("cannot handle %s internally", cmd);
 545         }
 546
 547         /* Look for flags.. */
 548         argv++;
 549         argc--;
 550         handle_options(&argv, &argc, NULL);
 551         if (argc > 0) {
 552                 if (!prefixcmp(argv[0], "--"))
 553                         argv[0] += 2;
 554         } else {
 555                 /* The user didn't specify a command; give them help */
 556                 commit_pager_choice();
 557                 printf("usage: %s\n\n", git_usage_string);
 558                 list_common_cmds_help();
 559                 printf("\n%s\n", _(git_more_info_string));
 560                 exit(1);
 561         }
 562         cmd = argv[0];
 563
 564         /*
 565          * We use PATH to find git commands, but we prepend some higher
 566          * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
 567          * environment, and the $(gitexecdir) from the Makefile at build
 568          * time.
 569          */
 570         setup_path();
 571
 572         while (1) {
 573                 static int done_help = 0;
 574                 static int was_alias = 0;
 575                 was_alias = run_argv(&argc, &argv);
 576                 if (errno != ENOENT)
 577                         break;
 578                 if (was_alias) {
 579                         fprintf(stderr, "Expansion of alias '%s' failed; "
 580                                 "'%s' is not a git command\n",
 581                                 cmd, argv[0]);
 582                         exit(1);
 583                 }
 584                 if (!done_help) {
 585                         cmd = argv[0] = help_unknown_cmd(cmd);
 586                         done_help = 1;
 587                 } else
 588                         break;
 589         }
 590
 591         fprintf(stderr, "Failed to run command '%s': %s\n",
 592                 cmd, strerror(errno));
 593
 594         return 1;
 595 }