run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4 #include "sigchain.h"
   5 #include "argv-array.h"
   6
   7 struct child_to_clean {
   8         pid_t pid;
   9         struct child_to_clean *next;
  10 };
  11 static struct child_to_clean *children_to_clean;
  12 static int installed_child_cleanup_handler;
  13
  14 static void cleanup_children(int sig)
  15 {
  16         while (children_to_clean) {
  17                 struct child_to_clean *p = children_to_clean;
  18                 children_to_clean = p->next;
  19                 kill(p->pid, sig);
  20                 free(p);
  21         }
  22 }
  23
  24 static void cleanup_children_on_signal(int sig)
  25 {
  26         cleanup_children(sig);
  27         sigchain_pop(sig);
  28         raise(sig);
  29 }
  30
  31 static void cleanup_children_on_exit(void)
  32 {
  33         cleanup_children(SIGTERM);
  34 }
  35
  36 static void mark_child_for_cleanup(pid_t pid)
  37 {
  38         struct child_to_clean *p = xmalloc(sizeof(*p));
  39         p->pid = pid;
  40         p->next = children_to_clean;
  41         children_to_clean = p;
  42
  43         if (!installed_child_cleanup_handler) {
  44                 atexit(cleanup_children_on_exit);
  45                 sigchain_push_common(cleanup_children_on_signal);
  46                 installed_child_cleanup_handler = 1;
  47         }
  48 }
  49
  50 static void clear_child_for_cleanup(pid_t pid)
  51 {
  52         struct child_to_clean **last, *p;
  53
  54         last = &children_to_clean;
  55         for (p = children_to_clean; p; p = p->next) {
  56                 if (p->pid == pid) {
  57                         *last = p->next;
  58                         free(p);
  59                         return;
  60                 }
  61         }
  62 }
  63
  64 static inline void close_pair(int fd[2])
  65 {
  66         close(fd[0]);
  67         close(fd[1]);
  68 }
  69
  70 #ifndef WIN32
  71 static inline void dup_devnull(int to)
  72 {
  73         int fd = open("/dev/null", O_RDWR);
  74         dup2(fd, to);
  75         close(fd);
  76 }
  77 #endif
  78
  79 static char *locate_in_PATH(const char *file)
  80 {
  81         const char *p = getenv("PATH");
  82         struct strbuf buf = STRBUF_INIT;
  83
  84         if (!p || !*p)
  85                 return NULL;
  86
  87         while (1) {
  88                 const char *end = strchrnul(p, ':');
  89
  90                 strbuf_reset(&buf);
  91
  92                 /* POSIX specifies an empty entry as the current directory. */
  93                 if (end != p) {
  94                         strbuf_add(&buf, p, end - p);
  95                         strbuf_addch(&buf, '/');
  96                 }
  97                 strbuf_addstr(&buf, file);
  98
  99                 if (!access(buf.buf, F_OK))
 100                         return strbuf_detach(&buf, NULL);
 101
 102                 if (!*end)
 103                         break;
 104                 p = end + 1;
 105         }
 106
 107         strbuf_release(&buf);
 108         return NULL;
 109 }
 110
 111 static int exists_in_PATH(const char *file)
 112 {
 113         char *r = locate_in_PATH(file);
 114         free(r);
 115         return r != NULL;
 116 }
 117
 118 int sane_execvp(const char *file, char * const argv[])
 119 {
 120         if (!execvp(file, argv))
 121                 return 0; /* cannot happen ;-) */
 122
 123         /*
 124          * When a command can't be found because one of the directories
 125          * listed in $PATH is unsearchable, execvp reports EACCES, but
 126          * careful usability testing (read: analysis of occasional bug
 127          * reports) reveals that "No such file or directory" is more
 128          * intuitive.
 129          *
 130          * We avoid commands with "/", because execvp will not do $PATH
 131          * lookups in that case.
 132          *
 133          * The reassignment of EACCES to errno looks like a no-op below,
 134          * but we need to protect against exists_in_PATH overwriting errno.
 135          */
 136         if (errno == EACCES && !strchr(file, '/'))
 137                 errno = exists_in_PATH(file) ? EACCES : ENOENT;
 138         return -1;
 139 }
 140
 141 static const char **prepare_shell_cmd(const char **argv)
 142 {
 143         int argc, nargc = 0;
 144         const char **nargv;
 145
 146         for (argc = 0; argv[argc]; argc++)
 147                 ; /* just counting */
 148         /* +1 for NULL, +3 for "sh -c" plus extra $0 */
 149         nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
 150
 151         if (argc < 1)
 152                 die("BUG: shell command is empty");
 153
 154         if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
 155                 nargv[nargc++] = "sh";
 156                 nargv[nargc++] = "-c";
 157
 158                 if (argc < 2)
 159                         nargv[nargc++] = argv[0];
 160                 else {
 161                         struct strbuf arg0 = STRBUF_INIT;
 162                         strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
 163                         nargv[nargc++] = strbuf_detach(&arg0, NULL);
 164                 }
 165         }
 166
 167         for (argc = 0; argv[argc]; argc++)
 168                 nargv[nargc++] = argv[argc];
 169         nargv[nargc] = NULL;
 170
 171         return nargv;
 172 }
 173
 174 #ifndef WIN32
 175 static int execv_shell_cmd(const char **argv)
 176 {
 177         const char **nargv = prepare_shell_cmd(argv);
 178         trace_argv_printf(nargv, "trace: exec:");
 179         sane_execvp(nargv[0], (char **)nargv);
 180         free(nargv);
 181         return -1;
 182 }
 183 #endif
 184
 185 #ifndef WIN32
 186 static int child_err = 2;
 187 static int child_notifier = -1;
 188
 189 static void notify_parent(void)
 190 {
 191         /*
 192          * execvp failed.  If possible, we'd like to let start_command
 193          * know, so failures like ENOENT can be handled right away; but
 194          * otherwise, finish_command will still report the error.
 195          */
 196         xwrite(child_notifier, "", 1);
 197 }
 198
 199 static NORETURN void die_child(const char *err, va_list params)
 200 {
 201         vwritef(child_err, "fatal: ", err, params);
 202         exit(128);
 203 }
 204
 205 static void error_child(const char *err, va_list params)
 206 {
 207         vwritef(child_err, "error: ", err, params);
 208 }
 209 #endif
 210
 211 static inline void set_cloexec(int fd)
 212 {
 213         int flags = fcntl(fd, F_GETFD);
 214         if (flags >= 0)
 215                 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 216 }
 217
 218 static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 219 {
 220         int status, code = -1;
 221         pid_t waiting;
 222         int failed_errno = 0;
 223
 224         while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 225                 ;       /* nothing */
 226
 227         if (waiting < 0) {
 228                 failed_errno = errno;
 229                 error("waitpid for %s failed: %s", argv0, strerror(errno));
 230         } else if (waiting != pid) {
 231                 error("waitpid is confused (%s)", argv0);
 232         } else if (WIFSIGNALED(status)) {
 233                 code = WTERMSIG(status);
 234                 error("%s died of signal %d", argv0, code);
 235                 /*
 236                  * This return value is chosen so that code & 0xff
 237                  * mimics the exit code that a POSIX shell would report for
 238                  * a program that died from this signal.
 239                  */
 240                 code -= 128;
 241         } else if (WIFEXITED(status)) {
 242                 code = WEXITSTATUS(status);
 243                 /*
 244                  * Convert special exit code when execvp failed.
 245                  */
 246                 if (code == 127) {
 247                         code = -1;
 248                         failed_errno = ENOENT;
 249                 }
 250         } else {
 251                 error("waitpid is confused (%s)", argv0);
 252         }
 253
 254         clear_child_for_cleanup(pid);
 255
 256         errno = failed_errno;
 257         return code;
 258 }
 259
 260 int start_command(struct child_process *cmd)
 261 {
 262         int need_in, need_out, need_err;
 263         int fdin[2], fdout[2], fderr[2];
 264         int failed_errno = failed_errno;
 265
 266         /*
 267          * In case of errors we must keep the promise to close FDs
 268          * that have been passed in via ->in and ->out.
 269          */
 270
 271         need_in = !cmd->no_stdin && cmd->in < 0;
 272         if (need_in) {
 273                 if (pipe(fdin) < 0) {
 274                         failed_errno = errno;
 275                         if (cmd->out > 0)
 276                                 close(cmd->out);
 277                         goto fail_pipe;
 278                 }
 279                 cmd->in = fdin[1];
 280         }
 281
 282         need_out = !cmd->no_stdout
 283                 && !cmd->stdout_to_stderr
 284                 && cmd->out < 0;
 285         if (need_out) {
 286                 if (pipe(fdout) < 0) {
 287                         failed_errno = errno;
 288                         if (need_in)
 289                                 close_pair(fdin);
 290                         else if (cmd->in)
 291                                 close(cmd->in);
 292                         goto fail_pipe;
 293                 }
 294                 cmd->out = fdout[0];
 295         }
 296
 297         need_err = !cmd->no_stderr && cmd->err < 0;
 298         if (need_err) {
 299                 if (pipe(fderr) < 0) {
 300                         failed_errno = errno;
 301                         if (need_in)
 302                                 close_pair(fdin);
 303                         else if (cmd->in)
 304                                 close(cmd->in);
 305                         if (need_out)
 306                                 close_pair(fdout);
 307                         else if (cmd->out)
 308                                 close(cmd->out);
 309 fail_pipe:
 310                         error("cannot create pipe for %s: %s",
 311                                 cmd->argv[0], strerror(failed_errno));
 312                         errno = failed_errno;
 313                         return -1;
 314                 }
 315                 cmd->err = fderr[0];
 316         }
 317
 318         trace_argv_printf(cmd->argv, "trace: run_command:");
 319         fflush(NULL);
 320
 321 #ifndef WIN32
 322 {
 323         int notify_pipe[2];
 324         if (pipe(notify_pipe))
 325                 notify_pipe[0] = notify_pipe[1] = -1;
 326
 327         cmd->pid = fork();
 328         if (!cmd->pid) {
 329                 /*
 330                  * Redirect the channel to write syscall error messages to
 331                  * before redirecting the process's stderr so that all die()
 332                  * in subsequent call paths use the parent's stderr.
 333                  */
 334                 if (cmd->no_stderr || need_err) {
 335                         child_err = dup(2);
 336                         set_cloexec(child_err);
 337                 }
 338                 set_die_routine(die_child);
 339                 set_error_routine(error_child);
 340
 341                 close(notify_pipe[0]);
 342                 set_cloexec(notify_pipe[1]);
 343                 child_notifier = notify_pipe[1];
 344                 atexit(notify_parent);
 345
 346                 if (cmd->no_stdin)
 347                         dup_devnull(0);
 348                 else if (need_in) {
 349                         dup2(fdin[0], 0);
 350                         close_pair(fdin);
 351                 } else if (cmd->in) {
 352                         dup2(cmd->in, 0);
 353                         close(cmd->in);
 354                 }
 355
 356                 if (cmd->no_stderr)
 357                         dup_devnull(2);
 358                 else if (need_err) {
 359                         dup2(fderr[1], 2);
 360                         close_pair(fderr);
 361                 } else if (cmd->err > 1) {
 362                         dup2(cmd->err, 2);
 363                         close(cmd->err);
 364                 }
 365
 366                 if (cmd->no_stdout)
 367                         dup_devnull(1);
 368                 else if (cmd->stdout_to_stderr)
 369                         dup2(2, 1);
 370                 else if (need_out) {
 371                         dup2(fdout[1], 1);
 372                         close_pair(fdout);
 373                 } else if (cmd->out > 1) {
 374                         dup2(cmd->out, 1);
 375                         close(cmd->out);
 376                 }
 377
 378                 if (cmd->dir && chdir(cmd->dir))
 379                         die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 380                             cmd->dir);
 381                 if (cmd->env) {
 382                         for (; *cmd->env; cmd->env++) {
 383                                 if (strchr(*cmd->env, '='))
 384                                         putenv((char *)*cmd->env);
 385                                 else
 386                                         unsetenv(*cmd->env);
 387                         }
 388                 }
 389                 if (cmd->preexec_cb) {
 390                         /*
 391                          * We cannot predict what the pre-exec callback does.
 392                          * Forgo parent notification.
 393                          */
 394                         close(child_notifier);
 395                         child_notifier = -1;
 396
 397                         cmd->preexec_cb();
 398                 }
 399                 if (cmd->git_cmd) {
 400                         execv_git_cmd(cmd->argv);
 401                 } else if (cmd->use_shell) {
 402                         execv_shell_cmd(cmd->argv);
 403                 } else {
 404                         sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
 405                 }
 406                 if (errno == ENOENT) {
 407                         if (!cmd->silent_exec_failure)
 408                                 error("cannot run %s: %s", cmd->argv[0],
 409                                         strerror(ENOENT));
 410                         exit(127);
 411                 } else {
 412                         die_errno("cannot exec '%s'", cmd->argv[0]);
 413                 }
 414         }
 415         if (cmd->pid < 0)
 416                 error("cannot fork() for %s: %s", cmd->argv[0],
 417                         strerror(failed_errno = errno));
 418         else if (cmd->clean_on_exit)
 419                 mark_child_for_cleanup(cmd->pid);
 420
 421         /*
 422          * Wait for child's execvp. If the execvp succeeds (or if fork()
 423          * failed), EOF is seen immediately by the parent. Otherwise, the
 424          * child process sends a single byte.
 425          * Note that use of this infrastructure is completely advisory,
 426          * therefore, we keep error checks minimal.
 427          */
 428         close(notify_pipe[1]);
 429         if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 430                 /*
 431                  * At this point we know that fork() succeeded, but execvp()
 432                  * failed. Errors have been reported to our stderr.
 433                  */
 434                 wait_or_whine(cmd->pid, cmd->argv[0],
 435                               cmd->silent_exec_failure);
 436                 failed_errno = errno;
 437                 cmd->pid = -1;
 438         }
 439         close(notify_pipe[0]);
 440
 441 }
 442 #else
 443 {
 444         int fhin = 0, fhout = 1, fherr = 2;
 445         const char **sargv = cmd->argv;
 446         char **env = environ;
 447
 448         if (cmd->no_stdin)
 449                 fhin = open("/dev/null", O_RDWR);
 450         else if (need_in)
 451                 fhin = dup(fdin[0]);
 452         else if (cmd->in)
 453                 fhin = dup(cmd->in);
 454
 455         if (cmd->no_stderr)
 456                 fherr = open("/dev/null", O_RDWR);
 457         else if (need_err)
 458                 fherr = dup(fderr[1]);
 459         else if (cmd->err > 2)
 460                 fherr = dup(cmd->err);
 461
 462         if (cmd->no_stdout)
 463                 fhout = open("/dev/null", O_RDWR);
 464         else if (cmd->stdout_to_stderr)
 465                 fhout = dup(fherr);
 466         else if (need_out)
 467                 fhout = dup(fdout[1]);
 468         else if (cmd->out > 1)
 469                 fhout = dup(cmd->out);
 470
 471         if (cmd->env)
 472                 env = make_augmented_environ(cmd->env);
 473
 474         if (cmd->git_cmd) {
 475                 cmd->argv = prepare_git_cmd(cmd->argv);
 476         } else if (cmd->use_shell) {
 477                 cmd->argv = prepare_shell_cmd(cmd->argv);
 478         }
 479
 480         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
 481                                   fhin, fhout, fherr);
 482         failed_errno = errno;
 483         if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 484                 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 485         if (cmd->clean_on_exit && cmd->pid >= 0)
 486                 mark_child_for_cleanup(cmd->pid);
 487
 488         if (cmd->env)
 489                 free_environ(env);
 490         if (cmd->git_cmd)
 491                 free(cmd->argv);
 492
 493         cmd->argv = sargv;
 494         if (fhin != 0)
 495                 close(fhin);
 496         if (fhout != 1)
 497                 close(fhout);
 498         if (fherr != 2)
 499                 close(fherr);
 500 }
 501 #endif
 502
 503         if (cmd->pid < 0) {
 504                 if (need_in)
 505                         close_pair(fdin);
 506                 else if (cmd->in)
 507                         close(cmd->in);
 508                 if (need_out)
 509                         close_pair(fdout);
 510                 else if (cmd->out)
 511                         close(cmd->out);
 512                 if (need_err)
 513                         close_pair(fderr);
 514                 else if (cmd->err)
 515                         close(cmd->err);
 516                 errno = failed_errno;
 517                 return -1;
 518         }
 519
 520         if (need_in)
 521                 close(fdin[0]);
 522         else if (cmd->in)
 523                 close(cmd->in);
 524
 525         if (need_out)
 526                 close(fdout[1]);
 527         else if (cmd->out)
 528                 close(cmd->out);
 529
 530         if (need_err)
 531                 close(fderr[1]);
 532         else if (cmd->err)
 533                 close(cmd->err);
 534
 535         return 0;
 536 }
 537
 538 int finish_command(struct child_process *cmd)
 539 {
 540         return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 541 }
 542
 543 int run_command(struct child_process *cmd)
 544 {
 545         int code = start_command(cmd);
 546         if (code)
 547                 return code;
 548         return finish_command(cmd);
 549 }
 550
 551 static void prepare_run_command_v_opt(struct child_process *cmd,
 552                                       const char **argv,
 553                                       int opt)
 554 {
 555         memset(cmd, 0, sizeof(*cmd));
 556         cmd->argv = argv;
 557         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 558         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 559         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 560         cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 561         cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 562         cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
 563 }
 564
 565 int run_command_v_opt(const char **argv, int opt)
 566 {
 567         struct child_process cmd;
 568         prepare_run_command_v_opt(&cmd, argv, opt);
 569         return run_command(&cmd);
 570 }
 571
 572 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 573 {
 574         struct child_process cmd;
 575         prepare_run_command_v_opt(&cmd, argv, opt);
 576         cmd.dir = dir;
 577         cmd.env = env;
 578         return run_command(&cmd);
 579 }
 580
 581 #ifndef NO_PTHREADS
 582 static pthread_t main_thread;
 583 static int main_thread_set;
 584 static pthread_key_t async_key;
 585
 586 static void *run_thread(void *data)
 587 {
 588         struct async *async = data;
 589         intptr_t ret;
 590
 591         pthread_setspecific(async_key, async);
 592         ret = async->proc(async->proc_in, async->proc_out, async->data);
 593         return (void *)ret;
 594 }
 595
 596 static NORETURN void die_async(const char *err, va_list params)
 597 {
 598         vreportf("fatal: ", err, params);
 599
 600         if (!pthread_equal(main_thread, pthread_self())) {
 601                 struct async *async = pthread_getspecific(async_key);
 602                 if (async->proc_in >= 0)
 603                         close(async->proc_in);
 604                 if (async->proc_out >= 0)
 605                         close(async->proc_out);
 606                 pthread_exit((void *)128);
 607         }
 608
 609         exit(128);
 610 }
 611 #endif
 612
 613 int start_async(struct async *async)
 614 {
 615         int need_in, need_out;
 616         int fdin[2], fdout[2];
 617         int proc_in, proc_out;
 618
 619         need_in = async->in < 0;
 620         if (need_in) {
 621                 if (pipe(fdin) < 0) {
 622                         if (async->out > 0)
 623                                 close(async->out);
 624                         return error("cannot create pipe: %s", strerror(errno));
 625                 }
 626                 async->in = fdin[1];
 627         }
 628
 629         need_out = async->out < 0;
 630         if (need_out) {
 631                 if (pipe(fdout) < 0) {
 632                         if (need_in)
 633                                 close_pair(fdin);
 634                         else if (async->in)
 635                                 close(async->in);
 636                         return error("cannot create pipe: %s", strerror(errno));
 637                 }
 638                 async->out = fdout[0];
 639         }
 640
 641         if (need_in)
 642                 proc_in = fdin[0];
 643         else if (async->in)
 644                 proc_in = async->in;
 645         else
 646                 proc_in = -1;
 647
 648         if (need_out)
 649                 proc_out = fdout[1];
 650         else if (async->out)
 651                 proc_out = async->out;
 652         else
 653                 proc_out = -1;
 654
 655 #ifdef NO_PTHREADS
 656         /* Flush stdio before fork() to avoid cloning buffers */
 657         fflush(NULL);
 658
 659         async->pid = fork();
 660         if (async->pid < 0) {
 661                 error("fork (async) failed: %s", strerror(errno));
 662                 goto error;
 663         }
 664         if (!async->pid) {
 665                 if (need_in)
 666                         close(fdin[1]);
 667                 if (need_out)
 668                         close(fdout[0]);
 669                 exit(!!async->proc(proc_in, proc_out, async->data));
 670         }
 671
 672         mark_child_for_cleanup(async->pid);
 673
 674         if (need_in)
 675                 close(fdin[0]);
 676         else if (async->in)
 677                 close(async->in);
 678
 679         if (need_out)
 680                 close(fdout[1]);
 681         else if (async->out)
 682                 close(async->out);
 683 #else
 684         if (!main_thread_set) {
 685                 /*
 686                  * We assume that the first time that start_async is called
 687                  * it is from the main thread.
 688                  */
 689                 main_thread_set = 1;
 690                 main_thread = pthread_self();
 691                 pthread_key_create(&async_key, NULL);
 692                 set_die_routine(die_async);
 693         }
 694
 695         if (proc_in >= 0)
 696                 set_cloexec(proc_in);
 697         if (proc_out >= 0)
 698                 set_cloexec(proc_out);
 699         async->proc_in = proc_in;
 700         async->proc_out = proc_out;
 701         {
 702                 int err = pthread_create(&async->tid, NULL, run_thread, async);
 703                 if (err) {
 704                         error("cannot create thread: %s", strerror(err));
 705                         goto error;
 706                 }
 707         }
 708 #endif
 709         return 0;
 710
 711 error:
 712         if (need_in)
 713                 close_pair(fdin);
 714         else if (async->in)
 715                 close(async->in);
 716
 717         if (need_out)
 718                 close_pair(fdout);
 719         else if (async->out)
 720                 close(async->out);
 721         return -1;
 722 }
 723
 724 int finish_async(struct async *async)
 725 {
 726 #ifdef NO_PTHREADS
 727         return wait_or_whine(async->pid, "child process", 0);
 728 #else
 729         void *ret = (void *)(intptr_t)(-1);
 730
 731         if (pthread_join(async->tid, &ret))
 732                 error("pthread_join failed");
 733         return (int)(intptr_t)ret;
 734 #endif
 735 }
 736
 737 int run_hook(const char *index_file, const char *name, ...)
 738 {
 739         struct child_process hook;
 740         struct argv_array argv = ARGV_ARRAY_INIT;
 741         const char *p, *env[2];
 742         char index[PATH_MAX];
 743         va_list args;
 744         int ret;
 745
 746         if (access(git_path("hooks/%s", name), X_OK) < 0)
 747                 return 0;
 748
 749         va_start(args, name);
 750         argv_array_push(&argv, git_path("hooks/%s", name));
 751         while ((p = va_arg(args, const char *)))
 752                 argv_array_push(&argv, p);
 753         va_end(args);
 754
 755         memset(&hook, 0, sizeof(hook));
 756         hook.argv = argv.argv;
 757         hook.no_stdin = 1;
 758         hook.stdout_to_stderr = 1;
 759         if (index_file) {
 760                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 761                 env[0] = index;
 762                 env[1] = NULL;
 763                 hook.env = env;
 764         }
 765
 766         ret = run_command(&hook);
 767         argv_array_clear(&argv);
 768         return ret;
 769 }