dog,yes,string1,yes,string2
cat,no,string3
mouse,no,string4,no,string5
horse
ferret

##</code><code>##

#!/bin/perl
use strict;
use warnings;
use Data::Dumper;
my $name="mouse";
open (FH, "datafile.txt")||die "cannot open file";
while ( <FH> ) { 
   next unless s/^(.*?):\s*//;
   $HoA{$1} = [ split /,/ ];
 }
print Dumper(%HoA);
my $success="yes";
my $description="new string";
push @{ $HoA{$name} }, $success, $description;
for $venue ( keys %HoA ) {
   print FH "$venue @{ $HoA{$venue} }\n";
}