posix/execlp.c

   1 /* Copyright (C) 1991-2021 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <unistd.h>
  19 #include <stdarg.h>
  20 #include <errno.h>
  21 #include <sys/param.h>
  22 #include <stddef.h>
  23
  24 /* Execute FILE, searching in the `PATH' environment variable if
  25    it contains no slashes, with all arguments after FILE until a
  26    NULL pointer and environment from `environ'.  */
  27 int
  28 execlp (const char *file, const char *arg, ...)
  29 {
  30   ptrdiff_t argc;
  31   va_list ap;
  32   va_start (ap, arg);
  33   for (argc = 1; va_arg (ap, const char *); argc++)
  34     {
  35       if (argc == INT_MAX)
  36         {
  37           va_end (ap);
  38           errno = E2BIG;
  39           return -1;
  40         }
  41     }
  42   va_end (ap);
  43
  44   /* Although posix does not state execlp as an async-safe function
  45      it can not use malloc to allocate the arguments since it might
  46      be used in a vfork scenario and it may lead to malloc internal
  47      bad state.  */
  48   ptrdiff_t i;
  49   char *argv[argc + 1];
  50   va_start (ap, arg);
  51   argv[0] = (char *) arg;
  52   for (i = 1; i <= argc; i++)
  53     argv[i] = va_arg (ap, char *);
  54   va_end (ap);
  55
  56   return __execvpe (file, argv, __environ);
  57 }
  58 libc_hidden_def (execlp)