usr/src/lib/libc/port/sys/execl.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  *      execl(name, arg0, arg1, ..., argn, 0)
  34  *      environment automatically passed.
  35  */
  36
  37 #pragma weak _execl = execl
  38
  39 #include "lint.h"
  40 #include <alloca.h>
  41 #include <malloc.h>
  42 #include <stdarg.h>
  43 #include <sys/types.h>
  44 #include <unistd.h>
  45
  46 /*VARARGS1*/
  47 int
  48 execl(const char *name, const char *arg0, ...)
  49 {
  50         char **argp;
  51         va_list args;
  52         char **argvec;
  53         extern char **_environ;
  54         int err;
  55         int nargs = 0;
  56         char *nextarg;
  57
  58         /*
  59          * count the number of arguments in the variable argument list
  60          * and allocate an argument vector for them on the stack,
  61          * adding an extra element for a terminating null pointer
  62          */
  63
  64         va_start(args, arg0);
  65         while (va_arg(args, char *) != NULL) {
  66                 nargs++;
  67         }
  68         va_end(args);
  69
  70         /*
  71          * load the arguments in the variable argument list
  72          * into the argument vector and add the terminating null pointer
  73          */
  74
  75         va_start(args, arg0);
  76
  77         /* workaround for bugid 1242839 */
  78         argvec = (char **)alloca((size_t)((nargs + 2) * sizeof (char *)));
  79         argp = argvec;
  80         *argp++ = (char *)arg0;
  81         while ((nextarg = va_arg(args, char *)) != NULL) {
  82                 *argp++ = nextarg;
  83         }
  84         va_end(args);
  85         *argp = NULL;
  86
  87         /*
  88          * call execve()
  89          */
  90
  91         err = execve(name, argvec, _environ);
  92         return (err);
  93 }