#!/usr/bin/perl
use strict;
use warnings;

##############
##  03/14/19
##  Exercise reads from file, then lets user interactively submit matching search criteria

my $input_file = shift @ARGV;
open my $fh, '<', $input_file or die "unable to open $input_file for searching $!";
chomp(my @strings = <$fh>); 

my $pattern;
while ( (print 'Please enter a pattern: '),$pattern=<STDIN>, $pattern !~ /\A\s*\Z/)
{
       chomp $pattern;
       
       my @matches = eval { 
          grep /$pattern/, @strings;
       }; ## end of eval
       if ($@) {
          print "Error: $@";
       } else {
           my $count = @matches;
           print "There were $count matching strings:\n",
             join ("\n",@matches);
       }
       
       print "\n";
}