minix/lib/libc/posix/_execl.c

89 lines
2.9 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#define execl _execl
#define execve _execve
#include <unistd.h>
#include <minix/compiler.h>
#include <errno.h>
#include <stdarg.h>
#include <sys/types.h>
#include <stdlib.h>
#include <alloca.h>
#include <lib.h>
#ifndef __UNCONST
#define __UNCONST(x) ((void *) (x))
#endif
extern char * const **_penviron; /* The default environment. */
int
execl(const char *path, const char *arg, ...)
/* execl("/bin/sh", "sh", "-c", "example", (char *) 0); */
{
#if FUNC_ARGS_ARRAY
/*
* Assumption: The C-implementation for this machine pushes
* function arguments downwards on the stack making a perfect
* argument array. Luckily this is almost always so.
*
* execl() - execute Author: Kees J. Bot, 21 Jan 1994
*/
return execve(path, (char * const *) &arg, *_penviron);
#else
/*
* Indeed, GCC (4.4.1) behaves similarly to ACK. Nonetheless, let's
* stay the safe side. LLVM (llvm-gcc) doesn't make the aforementioned
* assumption.
*/
va_list ap;
char **argv;
int i;
va_start(ap, arg);
for (i = 2; va_arg(ap, char *) != NULL; i++)
continue;
va_end(ap);
if ((argv = alloca(i * sizeof (char *))) == NULL) {
errno = ENOMEM;
return -1;
}
va_start(ap, arg);
argv[0] = __UNCONST(arg);
for (i = 1; (argv[i] = va_arg(ap, char *)) != NULL; i++)
continue;
va_end(ap);
return execve(path, (char * const *) argv, *_penviron);
#endif
}