/************************************************************************
*                                                                       *    
*  Copyright Digital Equipment Corporation 1998. All rights reserved.   *
*                                                                       *    
*  Restricted Rights: Use, duplication, or disclosure by the U.S.       *    
*  Government is subject to restrictions as set forth in subparagraph   *    
*  (c) (1) (ii) of DFARS 252.227-7013, or in FAR 52.227-19, or in FAR   *    
*  52.227-14 Alt. III, as applicable.                                   *    
*                                                                       *    
*  This software is proprietary to and embodies the confidential        *    
*  technology of Digital Equipment Corporation. Possession, use, or     *    
*  copying of this software and media is authorized only pursuant to a  *    
*  valid written license from Digital or an authorized sublicensor.     *    
*                                                                       *    
************************************************************************/

/*      chap_5_exec_image.c     */
                                                                
/* This example creates the child process.  The only    */
/* functionality given to the child is the ability to   */
/* print a message 10 times.                            */

#include <climsgdef.h>  /* CLI status values  */
#include <stdio.h>
#include <perror.h>
#include <processes.h>
#include <stdlib.h>

static const char *child_name = "chap_5_exec_image_child.exe" ;

main()
{
    int status,
        cstatus;

    /* NOTE:                                            */
    /*    Any local automatic variables, even those     */
    /*    having the volitile attribute, may have       */
    /*    indeterminant values if they are modified     */
    /*    between the vfork() call and the matching     */
    /*    exec() call.                                  */

    if ((status = vfork()) != 0) {
        /* This is either an error OR                   */
        /* the "second" vfork return, taking us "back"  */
        /* to parent mode.                              */
        if (status < 0)
            printf("Parent - Child process failed\n");
        else {
            printf("Parent - Waiting for Child\n");
            if ((status = wait(&cstatus)) == -1)
                perror("Parent - Wait failed");
            else if (cstatus == CLI$_IMAGEFNF)
                printf("Parent - Child does not exist\n");

            else
                printf("Parent - Child final status: %d\n", cstatus);
        }
    }
    else {      /* The FIRST Vfork return is zero, do the exec() */
        printf("Parent - Starting Child\n");
        if ((status = execl(child_name, 0)) == -1) {
            perror("Parent - Execl failed");
            exit(EXIT_FAILURE);
        }
    }
}