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 #ifndef SHELL_PATH
   8 # define SHELL_PATH "/bin/sh"
   9 #endif
  10
  11 struct child_to_clean {
  12         pid_t pid;
  13         struct child_to_clean *next;
  14 };
  15 static struct child_to_clean *children_to_clean;
  16 static int installed_child_cleanup_handler;
  17
  18 static void cleanup_children(int sig)
  19 {
  20         while (children_to_clean) {
  21                 struct child_to_clean *p = children_to_clean;
  22                 children_to_clean = p->next;
  23                 kill(p->pid, sig);
  24                 free(p);
  25         }
  26 }
  27
  28 static void cleanup_children_on_signal(int sig)
  29 {
  30         cleanup_children(sig);
  31         sigchain_pop(sig);
  32         raise(sig);
  33 }
  34
  35 static void cleanup_children_on_exit(void)
  36 {
  37         cleanup_children(SIGTERM);
  38 }
  39
  40 static void mark_child_for_cleanup(pid_t pid)
  41 {
  42         struct child_to_clean *p = xmalloc(sizeof(*p));
  43         p->pid = pid;
  44         p->next = children_to_clean;
  45         children_to_clean = p;
  46
  47         if (!installed_child_cleanup_handler) {
  48                 atexit(cleanup_children_on_exit);
  49                 sigchain_push_common(cleanup_children_on_signal);
  50                 installed_child_cleanup_handler = 1;
  51         }
  52 }
  53
  54 static void clear_child_for_cleanup(pid_t pid)
  55 {
  56         struct child_to_clean **pp;
  57
  58         for (pp = &children_to_clean; *pp; pp = &(*pp)->next) {
  59                 struct child_to_clean *clean_me = *pp;
  60
  61                 if (clean_me->pid == pid) {
  62                         *pp = clean_me->next;
  63                         free(clean_me);
  64                         return;
  65                 }
  66         }
  67 }
  68
  69 static inline void close_pair(int fd[2])
  70 {
  71         close(fd[0]);
  72         close(fd[1]);
  73 }
  74
  75 #ifndef GIT_WINDOWS_NATIVE
  76 static inline void dup_devnull(int to)
  77 {
  78         int fd = open("/dev/null", O_RDWR);
  79         if (fd < 0)
  80                 die_errno(_("open /dev/null failed"));
  81         if (dup2(fd, to) < 0)
  82                 die_errno(_("dup2(%d,%d) failed"), fd, to);
  83         close(fd);
  84 }
  85 #endif
  86
  87 static char *locate_in_PATH(const char *file)
  88 {
  89         const char *p = getenv("PATH");
  90         struct strbuf buf = STRBUF_INIT;
  91
  92         if (!p || !*p)
  93                 return NULL;
  94
  95         while (1) {
  96                 const char *end = strchrnul(p, ':');
  97
  98                 strbuf_reset(&buf);
  99
 100                 /* POSIX specifies an empty entry as the current directory. */
 101                 if (end != p) {
 102                         strbuf_add(&buf, p, end - p);
 103                         strbuf_addch(&buf, '/');
 104                 }
 105                 strbuf_addstr(&buf, file);
 106
 107                 if (!access(buf.buf, F_OK))
 108                         return strbuf_detach(&buf, NULL);
 109
 110                 if (!*end)
 111                         break;
 112                 p = end + 1;
 113         }
 114
 115         strbuf_release(&buf);
 116         return NULL;
 117 }
 118
 119 static int exists_in_PATH(const char *file)
 120 {
 121         char *r = locate_in_PATH(file);
 122         free(r);
 123         return r != NULL;
 124 }
 125
 126 int sane_execvp(const char *file, char * const argv[])
 127 {
 128         if (!execvp(file, argv))
 129                 return 0; /* cannot happen ;-) */
 130
 131         /*
 132          * When a command can't be found because one of the directories
 133          * listed in $PATH is unsearchable, execvp reports EACCES, but
 134          * careful usability testing (read: analysis of occasional bug
 135          * reports) reveals that "No such file or directory" is more
 136          * intuitive.
 137          *
 138          * We avoid commands with "/", because execvp will not do $PATH
 139          * lookups in that case.
 140          *
 141          * The reassignment of EACCES to errno looks like a no-op below,
 142          * but we need to protect against exists_in_PATH overwriting errno.
 143          */
 144         if (errno == EACCES && !strchr(file, '/'))
 145                 errno = exists_in_PATH(file) ? EACCES : ENOENT;
 146         else if (errno == ENOTDIR && !strchr(file, '/'))
 147                 errno = ENOENT;
 148         return -1;
 149 }
 150
 151 static const char **prepare_shell_cmd(const char **argv)
 152 {
 153         int argc, nargc = 0;
 154         const char **nargv;
 155
 156         for (argc = 0; argv[argc]; argc++)
 157                 ; /* just counting */
 158         /* +1 for NULL, +3 for "sh -c" plus extra $0 */
 159         nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
 160
 161         if (argc < 1)
 162                 die("BUG: shell command is empty");
 163
 164         if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
 165 #ifndef GIT_WINDOWS_NATIVE
 166                 nargv[nargc++] = SHELL_PATH;
 167 #else
 168                 nargv[nargc++] = "sh";
 169 #endif
 170                 nargv[nargc++] = "-c";
 171
 172                 if (argc < 2)
 173                         nargv[nargc++] = argv[0];
 174                 else {
 175                         struct strbuf arg0 = STRBUF_INIT;
 176                         strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
 177                         nargv[nargc++] = strbuf_detach(&arg0, NULL);
 178                 }
 179         }
 180
 181         for (argc = 0; argv[argc]; argc++)
 182                 nargv[nargc++] = argv[argc];
 183         nargv[nargc] = NULL;
 184
 185         return nargv;
 186 }
 187
 188 #ifndef GIT_WINDOWS_NATIVE
 189 static int execv_shell_cmd(const char **argv)
 190 {
 191         const char **nargv = prepare_shell_cmd(argv);
 192         trace_argv_printf(nargv, "trace: exec:");
 193         sane_execvp(nargv[0], (char **)nargv);
 194         free(nargv);
 195         return -1;
 196 }
 197 #endif
 198
 199 #ifndef GIT_WINDOWS_NATIVE
 200 static int child_err = 2;
 201 static int child_notifier = -1;
 202
 203 static void notify_parent(void)
 204 {
 205         /*
 206          * execvp failed.  If possible, we'd like to let start_command
 207          * know, so failures like ENOENT can be handled right away; but
 208          * otherwise, finish_command will still report the error.
 209          */
 210         xwrite(child_notifier, "", 1);
 211 }
 212
 213 static NORETURN void die_child(const char *err, va_list params)
 214 {
 215         vwritef(child_err, "fatal: ", err, params);
 216         exit(128);
 217 }
 218
 219 static void error_child(const char *err, va_list params)
 220 {
 221         vwritef(child_err, "error: ", err, params);
 222 }
 223 #endif
 224
 225 static inline void set_cloexec(int fd)
 226 {
 227         int flags = fcntl(fd, F_GETFD);
 228         if (flags >= 0)
 229                 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 230 }
 231
 232 static int wait_or_whine(pid_t pid, const char *argv0)
 233 {
 234         int status, code = -1;
 235         pid_t waiting;
 236         int failed_errno = 0;
 237
 238         while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 239                 ;       /* nothing */
 240
 241         if (waiting < 0) {
 242                 failed_errno = errno;
 243                 error("waitpid for %s failed: %s", argv0, strerror(errno));
 244         } else if (waiting != pid) {
 245                 error("waitpid is confused (%s)", argv0);
 246         } else if (WIFSIGNALED(status)) {
 247                 code = WTERMSIG(status);
 248                 if (code != SIGINT && code != SIGQUIT)
 249                         error("%s died of signal %d", argv0, code);
 250                 /*
 251                  * This return value is chosen so that code & 0xff
 252                  * mimics the exit code that a POSIX shell would report for
 253                  * a program that died from this signal.
 254                  */
 255                 code += 128;
 256         } else if (WIFEXITED(status)) {
 257                 code = WEXITSTATUS(status);
 258                 /*
 259                  * Convert special exit code when execvp failed.
 260                  */
 261                 if (code == 127) {
 262                         code = -1;
 263                         failed_errno = ENOENT;
 264                 }
 265         } else {
 266                 error("waitpid is confused (%s)", argv0);
 267         }
 268
 269         clear_child_for_cleanup(pid);
 270
 271         errno = failed_errno;
 272         return code;
 273 }
 274
 275 int start_command(struct child_process *cmd)
 276 {
 277         int need_in, need_out, need_err;
 278         int fdin[2], fdout[2], fderr[2];
 279         int failed_errno;
 280         char *str;
 281
 282         if (!cmd->argv)
 283                 cmd->argv = cmd->args.argv;
 284
 285         /*
 286          * In case of errors we must keep the promise to close FDs
 287          * that have been passed in via ->in and ->out.
 288          */
 289
 290         need_in = !cmd->no_stdin && cmd->in < 0;
 291         if (need_in) {
 292                 if (pipe(fdin) < 0) {
 293                         failed_errno = errno;
 294                         if (cmd->out > 0)
 295                                 close(cmd->out);
 296                         str = "standard input";
 297                         goto fail_pipe;
 298                 }
 299                 cmd->in = fdin[1];
 300         }
 301
 302         need_out = !cmd->no_stdout
 303                 && !cmd->stdout_to_stderr
 304                 && cmd->out < 0;
 305         if (need_out) {
 306                 if (pipe(fdout) < 0) {
 307                         failed_errno = errno;
 308                         if (need_in)
 309                                 close_pair(fdin);
 310                         else if (cmd->in)
 311                                 close(cmd->in);
 312                         str = "standard output";
 313                         goto fail_pipe;
 314                 }
 315                 cmd->out = fdout[0];
 316         }
 317
 318         need_err = !cmd->no_stderr && cmd->err < 0;
 319         if (need_err) {
 320                 if (pipe(fderr) < 0) {
 321                         failed_errno = errno;
 322                         if (need_in)
 323                                 close_pair(fdin);
 324                         else if (cmd->in)
 325                                 close(cmd->in);
 326                         if (need_out)
 327                                 close_pair(fdout);
 328                         else if (cmd->out)
 329                                 close(cmd->out);
 330                         str = "standard error";
 331 fail_pipe:
 332                         error("cannot create %s pipe for %s: %s",
 333                                 str, cmd->argv[0], strerror(failed_errno));
 334                         argv_array_clear(&cmd->args);
 335                         errno = failed_errno;
 336                         return -1;
 337                 }
 338                 cmd->err = fderr[0];
 339         }
 340
 341         trace_argv_printf(cmd->argv, "trace: run_command:");
 342         fflush(NULL);
 343
 344 #ifndef GIT_WINDOWS_NATIVE
 345 {
 346         int notify_pipe[2];
 347         if (pipe(notify_pipe))
 348                 notify_pipe[0] = notify_pipe[1] = -1;
 349
 350         cmd->pid = fork();
 351         failed_errno = errno;
 352         if (!cmd->pid) {
 353                 /*
 354                  * Redirect the channel to write syscall error messages to
 355                  * before redirecting the process's stderr so that all die()
 356                  * in subsequent call paths use the parent's stderr.
 357                  */
 358                 if (cmd->no_stderr || need_err) {
 359                         child_err = dup(2);
 360                         set_cloexec(child_err);
 361                 }
 362                 set_die_routine(die_child);
 363                 set_error_routine(error_child);
 364
 365                 close(notify_pipe[0]);
 366                 set_cloexec(notify_pipe[1]);
 367                 child_notifier = notify_pipe[1];
 368                 atexit(notify_parent);
 369
 370                 if (cmd->no_stdin)
 371                         dup_devnull(0);
 372                 else if (need_in) {
 373                         dup2(fdin[0], 0);
 374                         close_pair(fdin);
 375                 } else if (cmd->in) {
 376                         dup2(cmd->in, 0);
 377                         close(cmd->in);
 378                 }
 379
 380                 if (cmd->no_stderr)
 381                         dup_devnull(2);
 382                 else if (need_err) {
 383                         dup2(fderr[1], 2);
 384                         close_pair(fderr);
 385                 } else if (cmd->err > 1) {
 386                         dup2(cmd->err, 2);
 387                         close(cmd->err);
 388                 }
 389
 390                 if (cmd->no_stdout)
 391                         dup_devnull(1);
 392                 else if (cmd->stdout_to_stderr)
 393                         dup2(2, 1);
 394                 else if (need_out) {
 395                         dup2(fdout[1], 1);
 396                         close_pair(fdout);
 397                 } else if (cmd->out > 1) {
 398                         dup2(cmd->out, 1);
 399                         close(cmd->out);
 400                 }
 401
 402                 if (cmd->dir && chdir(cmd->dir))
 403                         die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 404                             cmd->dir);
 405                 if (cmd->env) {
 406                         for (; *cmd->env; cmd->env++) {
 407                                 if (strchr(*cmd->env, '='))
 408                                         putenv((char *)*cmd->env);
 409                                 else
 410                                         unsetenv(*cmd->env);
 411                         }
 412                 }
 413                 if (cmd->git_cmd)
 414                         execv_git_cmd(cmd->argv);
 415                 else if (cmd->use_shell)
 416                         execv_shell_cmd(cmd->argv);
 417                 else
 418                         sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
 419                 if (errno == ENOENT) {
 420                         if (!cmd->silent_exec_failure)
 421                                 error("cannot run %s: %s", cmd->argv[0],
 422                                         strerror(ENOENT));
 423                         exit(127);
 424                 } else {
 425                         die_errno("cannot exec '%s'", cmd->argv[0]);
 426                 }
 427         }
 428         if (cmd->pid < 0)
 429                 error("cannot fork() for %s: %s", cmd->argv[0],
 430                         strerror(errno));
 431         else if (cmd->clean_on_exit)
 432                 mark_child_for_cleanup(cmd->pid);
 433
 434         /*
 435          * Wait for child's execvp. If the execvp succeeds (or if fork()
 436          * failed), EOF is seen immediately by the parent. Otherwise, the
 437          * child process sends a single byte.
 438          * Note that use of this infrastructure is completely advisory,
 439          * therefore, we keep error checks minimal.
 440          */
 441         close(notify_pipe[1]);
 442         if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 443                 /*
 444                  * At this point we know that fork() succeeded, but execvp()
 445                  * failed. Errors have been reported to our stderr.
 446                  */
 447                 wait_or_whine(cmd->pid, cmd->argv[0]);
 448                 failed_errno = errno;
 449                 cmd->pid = -1;
 450         }
 451         close(notify_pipe[0]);
 452 }
 453 #else
 454 {
 455         int fhin = 0, fhout = 1, fherr = 2;
 456         const char **sargv = cmd->argv;
 457         char **env = environ;
 458
 459         if (cmd->no_stdin)
 460                 fhin = open("/dev/null", O_RDWR);
 461         else if (need_in)
 462                 fhin = dup(fdin[0]);
 463         else if (cmd->in)
 464                 fhin = dup(cmd->in);
 465
 466         if (cmd->no_stderr)
 467                 fherr = open("/dev/null", O_RDWR);
 468         else if (need_err)
 469                 fherr = dup(fderr[1]);
 470         else if (cmd->err > 2)
 471                 fherr = dup(cmd->err);
 472
 473         if (cmd->no_stdout)
 474                 fhout = open("/dev/null", O_RDWR);
 475         else if (cmd->stdout_to_stderr)
 476                 fhout = dup(fherr);
 477         else if (need_out)
 478                 fhout = dup(fdout[1]);
 479         else if (cmd->out > 1)
 480                 fhout = dup(cmd->out);
 481
 482         if (cmd->env)
 483                 env = make_augmented_environ(cmd->env);
 484
 485         if (cmd->git_cmd)
 486                 cmd->argv = prepare_git_cmd(cmd->argv);
 487         else if (cmd->use_shell)
 488                 cmd->argv = prepare_shell_cmd(cmd->argv);
 489
 490         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
 491                                   fhin, fhout, fherr);
 492         failed_errno = errno;
 493         if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 494                 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 495         if (cmd->clean_on_exit && cmd->pid >= 0)
 496                 mark_child_for_cleanup(cmd->pid);
 497
 498         if (cmd->env)
 499                 free_environ(env);
 500         if (cmd->git_cmd)
 501                 free(cmd->argv);
 502
 503         cmd->argv = sargv;
 504         if (fhin != 0)
 505                 close(fhin);
 506         if (fhout != 1)
 507                 close(fhout);
 508         if (fherr != 2)
 509                 close(fherr);
 510 }
 511 #endif
 512
 513         if (cmd->pid < 0) {
 514                 if (need_in)
 515                         close_pair(fdin);
 516                 else if (cmd->in)
 517                         close(cmd->in);
 518                 if (need_out)
 519                         close_pair(fdout);
 520                 else if (cmd->out)
 521                         close(cmd->out);
 522                 if (need_err)
 523                         close_pair(fderr);
 524                 else if (cmd->err)
 525                         close(cmd->err);
 526                 argv_array_clear(&cmd->args);
 527                 errno = failed_errno;
 528                 return -1;
 529         }
 530
 531         if (need_in)
 532                 close(fdin[0]);
 533         else if (cmd->in)
 534                 close(cmd->in);
 535
 536         if (need_out)
 537                 close(fdout[1]);
 538         else if (cmd->out)
 539                 close(cmd->out);
 540
 541         if (need_err)
 542                 close(fderr[1]);
 543         else if (cmd->err)
 544                 close(cmd->err);
 545
 546         return 0;
 547 }
 548
 549 int finish_command(struct child_process *cmd)
 550 {
 551         int ret = wait_or_whine(cmd->pid, cmd->argv[0]);
 552         argv_array_clear(&cmd->args);
 553         return ret;
 554 }
 555
 556 int run_command(struct child_process *cmd)
 557 {
 558         int code = start_command(cmd);
 559         if (code)
 560                 return code;
 561         return finish_command(cmd);
 562 }
 563
 564 static void prepare_run_command_v_opt(struct child_process *cmd,
 565                                       const char **argv,
 566                                       int opt)
 567 {
 568         memset(cmd, 0, sizeof(*cmd));
 569         cmd->argv = argv;
 570         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 571         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 572         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 573         cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 574         cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 575         cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
 576 }
 577
 578 int run_command_v_opt(const char **argv, int opt)
 579 {
 580         struct child_process cmd;
 581         prepare_run_command_v_opt(&cmd, argv, opt);
 582         return run_command(&cmd);
 583 }
 584
 585 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 586 {
 587         struct child_process cmd;
 588         prepare_run_command_v_opt(&cmd, argv, opt);
 589         cmd.dir = dir;
 590         cmd.env = env;
 591         return run_command(&cmd);
 592 }
 593
 594 #ifndef NO_PTHREADS
 595 static pthread_t main_thread;
 596 static int main_thread_set;
 597 static pthread_key_t async_key;
 598 static pthread_key_t async_die_counter;
 599
 600 static void *run_thread(void *data)
 601 {
 602         struct async *async = data;
 603         intptr_t ret;
 604
 605         pthread_setspecific(async_key, async);
 606         ret = async->proc(async->proc_in, async->proc_out, async->data);
 607         return (void *)ret;
 608 }
 609
 610 static NORETURN void die_async(const char *err, va_list params)
 611 {
 612         vreportf("fatal: ", err, params);
 613
 614         if (!pthread_equal(main_thread, pthread_self())) {
 615                 struct async *async = pthread_getspecific(async_key);
 616                 if (async->proc_in >= 0)
 617                         close(async->proc_in);
 618                 if (async->proc_out >= 0)
 619                         close(async->proc_out);
 620                 pthread_exit((void *)128);
 621         }
 622
 623         exit(128);
 624 }
 625
 626 static int async_die_is_recursing(void)
 627 {
 628         void *ret = pthread_getspecific(async_die_counter);
 629         pthread_setspecific(async_die_counter, (void *)1);
 630         return ret != NULL;
 631 }
 632
 633 #endif
 634
 635 int start_async(struct async *async)
 636 {
 637         int need_in, need_out;
 638         int fdin[2], fdout[2];
 639         int proc_in, proc_out;
 640
 641         need_in = async->in < 0;
 642         if (need_in) {
 643                 if (pipe(fdin) < 0) {
 644                         if (async->out > 0)
 645                                 close(async->out);
 646                         return error("cannot create pipe: %s", strerror(errno));
 647                 }
 648                 async->in = fdin[1];
 649         }
 650
 651         need_out = async->out < 0;
 652         if (need_out) {
 653                 if (pipe(fdout) < 0) {
 654                         if (need_in)
 655                                 close_pair(fdin);
 656                         else if (async->in)
 657                                 close(async->in);
 658                         return error("cannot create pipe: %s", strerror(errno));
 659                 }
 660                 async->out = fdout[0];
 661         }
 662
 663         if (need_in)
 664                 proc_in = fdin[0];
 665         else if (async->in)
 666                 proc_in = async->in;
 667         else
 668                 proc_in = -1;
 669
 670         if (need_out)
 671                 proc_out = fdout[1];
 672         else if (async->out)
 673                 proc_out = async->out;
 674         else
 675                 proc_out = -1;
 676
 677 #ifdef NO_PTHREADS
 678         /* Flush stdio before fork() to avoid cloning buffers */
 679         fflush(NULL);
 680
 681         async->pid = fork();
 682         if (async->pid < 0) {
 683                 error("fork (async) failed: %s", strerror(errno));
 684                 goto error;
 685         }
 686         if (!async->pid) {
 687                 if (need_in)
 688                         close(fdin[1]);
 689                 if (need_out)
 690                         close(fdout[0]);
 691                 exit(!!async->proc(proc_in, proc_out, async->data));
 692         }
 693
 694         mark_child_for_cleanup(async->pid);
 695
 696         if (need_in)
 697                 close(fdin[0]);
 698         else if (async->in)
 699                 close(async->in);
 700
 701         if (need_out)
 702                 close(fdout[1]);
 703         else if (async->out)
 704                 close(async->out);
 705 #else
 706         if (!main_thread_set) {
 707                 /*
 708                  * We assume that the first time that start_async is called
 709                  * it is from the main thread.
 710                  */
 711                 main_thread_set = 1;
 712                 main_thread = pthread_self();
 713                 pthread_key_create(&async_key, NULL);
 714                 pthread_key_create(&async_die_counter, NULL);
 715                 set_die_routine(die_async);
 716                 set_die_is_recursing_routine(async_die_is_recursing);
 717         }
 718
 719         if (proc_in >= 0)
 720                 set_cloexec(proc_in);
 721         if (proc_out >= 0)
 722                 set_cloexec(proc_out);
 723         async->proc_in = proc_in;
 724         async->proc_out = proc_out;
 725         {
 726                 int err = pthread_create(&async->tid, NULL, run_thread, async);
 727                 if (err) {
 728                         error("cannot create thread: %s", strerror(err));
 729                         goto error;
 730                 }
 731         }
 732 #endif
 733         return 0;
 734
 735 error:
 736         if (need_in)
 737                 close_pair(fdin);
 738         else if (async->in)
 739                 close(async->in);
 740
 741         if (need_out)
 742                 close_pair(fdout);
 743         else if (async->out)
 744                 close(async->out);
 745         return -1;
 746 }
 747
 748 int finish_async(struct async *async)
 749 {
 750 #ifdef NO_PTHREADS
 751         return wait_or_whine(async->pid, "child process");
 752 #else
 753         void *ret = (void *)(intptr_t)(-1);
 754
 755         if (pthread_join(async->tid, &ret))
 756                 error("pthread_join failed");
 757         return (int)(intptr_t)ret;
 758 #endif
 759 }
 760
 761 char *find_hook(const char *name)
 762 {
 763         char *path = git_path("hooks/%s", name);
 764         if (access(path, X_OK) < 0)
 765                 path = NULL;
 766
 767         return path;
 768 }
 769
 770 int run_hook_ve(const char *const *env, const char *name, va_list args)
 771 {
 772         struct child_process hook;
 773         const char *p;
 774
 775         p = find_hook(name);
 776         if (!p)
 777                 return 0;
 778
 779         memset(&hook, 0, sizeof(hook));
 780         argv_array_push(&hook.args, p);
 781         while ((p = va_arg(args, const char *)))
 782                 argv_array_push(&hook.args, p);
 783         hook.env = env;
 784         hook.no_stdin = 1;
 785         hook.stdout_to_stderr = 1;
 786
 787         return run_command(&hook);
 788 }
 789
 790 int run_hook_le(const char *const *env, const char *name, ...)
 791 {
 792         va_list args;
 793         int ret;
 794
 795         va_start(args, name);
 796         ret = run_hook_ve(env, name, args);
 797         va_end(args);
 798
 799         return ret;
 800 }
 801
 802 int run_hook_with_custom_index(const char *index_file, const char *name, ...)
 803 {
 804         const char *hook_env[3] =  { NULL };
 805         char index[PATH_MAX];
 806         va_list args;
 807         int ret;
 808
 809         snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 810         hook_env[0] = index;
 811
 812         va_start(args, name);
 813         ret = run_hook_ve(hook_env, name, args);
 814         va_end(args);
 815
 816         return ret;
 817 }