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/* -----------------------------------------------------------------------
child process synchronization functions
part of XfreeCD
Copyright 1998 by Brian C. Lane
http://www.brianlane.com/
==========================[ HISTORY ]==================================
05/09/98 Moved these functions into this seperate file
----------------------------------------------------------------------- */
#include <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
/*
Synchronize with the parent process. Wait until we receive a 'P'
from the parent. Send a 'C' to the parent in response
Return a 0 if all went ok
Return a -1 if something went wrong
*/
int parent_sync( int fd )
{
char c;
if( read( fd, &c, 1 ) != 1 )
return(-1);
if( write( fd, "C", 1 ) != 1 )
return(-1);
return(0);
}
/*
Synchronize with the child process. Send a 'P' to the child and wait
until a 'C' is received back.
Return a 0 if all went ok
Return a -1 if something went wrong
*/
int child_sync( int fd )
{
char c;
if( write( fd, "P", 1 ) != 1 )
return(-1);
if( read( fd, &c, 1 ) != 1 )
return(-1);
if( c != 'C' )
return(-1);
return(0);
}
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