# The syntax of the getppid function is parentid = getppid(); 
# A program that calls fork and getppid. 
#!/usr/local/bin/perl 

$otherid = fork(); 
if ($otherid == 0) { 
    # this is the child; retrieve parent ID 
    $otherid = getppid(); 
} else { 
    # this is the parent 
}