#/usr/bin/perl
use strict;
use warnings;
$|=1;  #turns stdio buffer off so that error line order is correct

while (defined (my $line = <DATA>))
{
    chomp $line;                #removes end of line character(s)
    next unless $line =~ /\S/;  # skip blank lines
    
    my ($motherId,$yearBirth,$individualId) = (split /\t/,$line)[4,13,2];
    $yearBirth //= "";  # DATA line 6 is a bit weird
                        # this defines $yearBirth as "" if undefined
    
    print "UniqId=$individualId  Mother=$motherId  BirthY=$yearBirth \n";

}

=Prints
UniqId=1  Mother=3  BirthY=51 
UniqId=2  Mother=  BirthY= 
UniqId=3  Mother=36  BirthY=65 
UniqId=4  Mother=3  BirthY=50 
UniqId=5  Mother=3  BirthY=47 
UniqId=6  Mother=3  BirthY= 
UniqId=7  Mother=3  BirthY= 
UniqId=8  Mother=3  BirthY=42 
UniqId=9  Mother=3  BirthY=39 
UniqId=10  Mother=3  BirthY=35 
UniqId=11  Mother=8  BirthY=11 
UniqId=12  Mother=8  BirthY=9 
=cut


__DATA__
BC000	1	1	2	3	F  		3	51					51	
BC000	0	2			M  									999
BC000	0	3	37	36	F  								65	
BC000	0	4	2	3	M  								50	50
BC000	0	5	2	3	F  			45					47	46
BC000	0	6	2	3	F  		3	42						
BC000	0	7	2	3	M  									999
BC000	0	8	2	3	F  		3						42	
BC000	0	9	2	3	F  		1						39	
BC000	0	10	2	3	F  		3						35	
BC000	0	11	45	8	M  								11	
BC000	0	12	45	8	F  								9