Update.
[glibc.git] / posix / execle.c
blobdc150a47022c013a942a033286ce4a63d953b67a
1 /* Copyright (C) 1991, 1997, 1998 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
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 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
19 #include <alloca.h>
20 #include <unistd.h>
21 #include <stdarg.h>
22 #include <stddef.h>
23 #include <string.h>
25 /* Execute PATH with all arguments after PATH until a NULL pointer,
26 and the argument after that for environment. */
27 int
28 execle (const char *path, const char *arg, ...)
30 size_t argv_max = 1024;
31 const char **argv = alloca (argv_max * sizeof (const char *));
32 const char *const *envp;
33 unsigned int i;
34 va_list args;
35 argv[0] = arg;
37 va_start(args, arg);
38 i = 0;
39 while (argv[i++] != NULL)
41 if (i == argv_max)
43 const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
45 if ((char *) nptr + argv_max == (char *) argv)
47 /* Stack grows down. */
48 argv = (const char **) memcpy (nptr, argv, i);
49 argv_max += i;
51 else if ((char *) argv + i == (char *) nptr)
52 /* Stack grows up. */
53 argv_max += i;
54 else
55 /* We have a hole in the stack. */
56 argv = (const char **) memcpy (nptr, argv, i);
59 argv[i] = va_arg (args, const char *);
62 envp = va_arg(args, const char *const *);
63 va_end(args);
65 return __execve(path, (char *const *) argv, (char *const *) envp);