posix/execlp.c

   1 /* Copyright (C) 1991-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <unistd.h>
  19 #include <stdarg.h>
  20 #include <errno.h>
  21 #include <sys/param.h>
  22
  23 /* Execute FILE, searching in the `PATH' environment variable if
  24    it contains no slashes, with all arguments after FILE until a
  25    NULL pointer and environment from `environ'.  */
  26 int
  27 execlp (const char *file, const char *arg, ...)
  28 {
  29   ptrdiff_t argc;
  30   va_list ap;
  31   va_start (ap, arg);
  32   for (argc = 1; va_arg (ap, const char *); argc++)
  33     {
  34       if (argc == INT_MAX)
  35         {
  36           va_end (ap);
  37           errno = E2BIG;
  38           return -1;
  39         }
  40     }
  41   va_end (ap);
  42
  43   /* Although posix does not state execlp as an async-safe function
  44      it can not use malloc to allocate the arguments since it might
  45      be used in a vfork scenario and it may lead to malloc internal
  46      bad state.  */
  47   ptrdiff_t i;
  48   char *argv[argc + 1];
  49   va_start (ap, arg);
  50   argv[0] = (char *) arg;
  51   for (i = 1; i <= argc; i++)
  52     argv[i] = va_arg (ap, char *);
  53   va_end (ap);
  54
  55   return __execvpe (file, argv, __environ);
  56 }
  57 libc_hidden_def (execlp)