#!/bin/gawk -f

BEGIN { if (ARGV[1] == "") { 
print "Merge the fields 'ZygositySR' with 'ZygosityGT' from"
print "the 'restricted' HCP csv file (data release S1200),"
print "producing a new field 'Zygosity' (last column)."
print ""
print "Example:"
print "mergezyg restricted.csv > restricted_zygmerged.csv"
print ""
print "Note that the '>' is mandatory."
print ""
print "_____________________________________"
print "Anderson M. Winkler"
print "FMRIB / Univ. of Oxford"
print "Mar/2017"
print "http://brainder.org"
exit } }

BEGIN { FS="," ; OFS="," } 
NR == 1 { print $0, "Zygosity" } 
NR >  1 { 
if ( $5 == "" || $5 == " " )
  { if ( $4 == "" || $4 == " " )
         { print $0, "" } 
    else { print $0, $4 } } 
else { print $0, $5 } }