Option parsing

x.pl

#Parse CLI arguments
use Getopt::Std;
my %options=();
getopts("f:d:t:l:o:",\%options);
my $pdbId = %options{f};
my $contactDistance = %options{d};
my $atomType = %options{t};
my $localContactSequenceDist = %options{l};
my $outputFile = %options{o} || "sscc.jpg";
die "No pdb id\n" unless $pdbId;
die "No contact distance\n" unless $contactDistance;
die "No atom type\n" unless $atomType;
die "No local contact dist\n" unless $localContactSequenceDist;