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[glibc.git] / posix / execl.c
blob62fd45db588f3123152dbd31e4aa5f0b613f3a8d
1 /* Copyright (C) 1991,92,94,97,98,99,2002 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 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.
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.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 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 #ifndef HAVE_GNU_LD
28 # define __environ environ
29 #endif
31 /* Execute PATH with all arguments after PATH until
32 a NULL pointer and environment from `environ'. */
33 int
34 execl (const char *path, const char *arg, ...)
36 size_t argv_max = 1024;
37 const char **argv = alloca (argv_max * sizeof (const char *));
38 unsigned int i;
39 va_list args;
41 argv[0] = arg;
43 va_start (args, arg);
44 i = 0;
45 while (argv[i++] != NULL)
47 if (i == argv_max)
49 const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
51 #ifndef _STACK_GROWS_UP
52 if ((char *) nptr + argv_max == (char *) argv)
54 /* Stack grows down. */
55 argv = (const char **) memcpy (nptr, argv,
56 i * sizeof (const char *));
57 argv_max += i;
59 else
60 #endif
61 #ifndef _STACK_GROWS_DOWN
62 if ((char *) argv + i == (char *) nptr)
63 /* Stack grows up. */
64 argv_max += i;
65 else
66 #endif
67 /* We have a hole in the stack. */
68 argv = (const char **) memcpy (nptr, argv,
69 i * sizeof (const char *));
72 argv[i] = va_arg (args, const char *);
74 va_end (args);
76 return __execve (path, (char *const *) argv, __environ);
78 libc_hidden_def (execl)