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[glibc.git] / posix / execle.c
blob546063fcc704aad9c87b68626826feaf8fd55209
1 /* Copyright (C) 1991, 1997, 1998, 1999 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 #include <stackinfo.h>
27 /* Execute PATH with all arguments after PATH until a NULL pointer,
28 and the argument after that for environment. */
29 int
30 execle (const char *path, const char *arg, ...)
32 size_t argv_max = 1024;
33 const char **argv = alloca (argv_max * sizeof (const char *));
34 const char *const *envp;
35 unsigned int i;
36 va_list args;
37 argv[0] = arg;
39 va_start (args, arg);
40 i = 0;
41 while (argv[i++] != NULL)
43 if (i == argv_max)
45 const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
47 #ifndef _STACK_GROWS_UP
48 if ((char *) nptr + argv_max == (char *) argv)
50 /* Stack grows down. */
51 argv = (const char **) memcpy (nptr, argv,
52 i * sizeof (const char *));
53 argv_max += i;
55 else
56 #endif
57 #ifndef _STACK_GROWS_DOWN
58 if ((char *) argv + i == (char *) nptr)
59 /* Stack grows up. */
60 argv_max += i;
61 else
62 #endif
63 /* We have a hole in the stack. */
64 argv = (const char **) memcpy (nptr, argv,
65 i * sizeof (const char *));
68 argv[i] = va_arg (args, const char *);
71 envp = va_arg (args, const char *const *);
72 va_end (args);
74 return __execve (path, (char *const *) argv, (char *const *) envp);