#!/usr/bin/perl
use strict;
use warnings;
use IO::All;
use v5.16;
##############
##  03/14/19
##  Exercise reads from file, then lets user interactively submit matching search criteria

die "Please provide a file to process!\n" unless (defined $ARGV[0]);

my @lines = io($ARGV[0])->chomp->slurp;      # Chomp as you slurp

while (1) {
    print 'Please enter a pattern: ';
    chomp(my $pattern = <STDIN>);
    last if $pattern =~ /\A\s*\Z/;
    my @matches = eval {
	grep /$pattern/, @lines;
    }; ## end of eval
    if ($@) {
	print "Error: $@";
    } else {
	my $count = @matches;
	print "There were $count matching strings:\n",
	    map "$_\n", @matches;
    }
    print "\n";
}