bash add chr to beginning of vcf
# Example usage:
awk '{if($0 !~ /^#/) print "chr"$0; else print $0}' input.vcf
# This converts a vcf file with numeric genome coordinates to one with
# chr in front of the chromosome number.
# Note, this command does the opposite operation, if needed:
awk '{gsub(/^chr/,""); print}' input.vcf