text: /* fork.c - fork and exec a process, connecting stdin/out w/pipes */
  /* $OpenLDAP$ */
  /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   *
   * Copyright 1998-2018 The OpenLDAP Foundation.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted only as authorized by the OpenLDAP
   * Public License.
   *
   * A copy of this license is available in the file LICENSE in the
   * top-level directory of the distribution or, alternatively, at
   * <http://www.OpenLDAP.org/license.html>.
   */
  /* Portions Copyright (c) 1995 Regents of the University of Michigan.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms are permitted
   * provided that this notice is preserved and that due credit is given
   * to the University of Michigan at Ann Arbor. The name of the University
   * may not be used to endorse or promote products derived from this
   * software without specific prior written permission. This software
   * is provided ``as is'' without express or implied warranty.
   */
  /* ACKNOWLEDGEMENTS:
   * This work was originally developed by the University of Michigan
   * (as part of U-MICH LDAP).
   */
  
  #include "portable.h"
  
  #include <stdio.h>
  
  #include <ac/errno.h>
  #include <ac/string.h>
  #include <ac/socket.h>
  #include <ac/unistd.h>
  
  #include "slap.h"
  #include "shell.h"
  
  pid_t
  forkandexec(
      char	**args,
      FILE	**rfp,
      FILE	**wfp
  )
  {
  	int	p2c[2] = { -1, -1 }, c2p[2];
  	pid_t	pid;
  
  	if ( pipe( p2c ) != 0 || pipe( c2p ) != 0 ) {
  		Debug( LDAP_DEBUG_ANY, "pipe failed\n", 0, 0, 0 );
  		close( p2c[0] );
  		close( p2c[1] );
  		return( -1 );
  	}
  
  	/*
  	 * what we're trying to set up looks like this:
  	 *	parent *wfp -> p2c[1] | p2c[0] -> stdin child
  	 *	parent *rfp <- c2p[0] | c2p[1] <- stdout child
  	 */
  
  	fflush( NULL );
  # ifdef HAVE_THR
  	pid = fork1();
  # else
  	pid = fork();
  # endif
  	if ( pid == 0 ) {		/* child */
  		/*
  		 * child could deadlock here due to resources locked
  		 * by our parent
  		 *
  		 * If so, configure --without-threads.
  		 */
  		if ( dup2( p2c[0], 0 ) == -1 || dup2( c2p[1], 1 ) == -1 ) {
  			Debug( LDAP_DEBUG_ANY, "dup2 failed\n", 0, 0, 0 );
  			exit( EXIT_FAILURE );
  		}
  	}
  	close( p2c[0] );
  	close( c2p[1] );
  	if ( pid <= 0 ) {
  		close( p2c[1] );
  		close( c2p[0] );
  	}
  	switch ( pid ) {
  	case 0:
  		execv( args[0], args );
  
  		Debug( LDAP_DEBUG_ANY, "execv failed\n", 0, 0, 0 );
  		exit( EXIT_FAILURE );
  
  	case -1:	/* trouble */
  		Debug( LDAP_DEBUG_ANY, "fork failed\n", 0, 0, 0 );
  		return( -1 );
  	}
  
  	/* parent */
  	if ( (*rfp = fdopen( c2p[0], "r" )) == NULL || (*wfp = fdopen( p2c[1],
  	    "w" )) == NULL ) {
  		Debug( LDAP_DEBUG_ANY, "fdopen failed\n", 0, 0, 0 );
  		if ( *rfp ) {
  			fclose( *rfp );
  			*rfp = NULL;
  		} else {
  			close( c2p[0] );
  		}
  		close( p2c[1] );
  
  		return( -1 );
  	}
  
  	return( pid );
  }
  