A Programming Job Interview Challenge #13 - Brackets, and Me...

Ok, I've been doing the programming quizzes here and have a solution...

In Perl:

$FILE = "expressions.txt";
open(FILE) or die("Could not open expressions file.");
foreach $OLINE (<FILE>)
{
 $LINE = $OLINE;
 if ($LINE =~ m/(^[\]}\)>])|([\[{\(<]$)/)
  { print "bad : $OLINE" }
 else
 {
  while ($LINE =~ m/(\[\])|({})|(\(\))|(<>)/)
   { $LINE =~ s/(\[\])|({})|(\(\))|(<>)//g }
  $strLen = length($LINE);
  if ($strLen > 1)
   { print "bad : $OLINE" }
  else
   { print "good : $OLINE" }
 }
}

And a C# console app to generate the "sample" strings (i.e. the "expressions.txt" file used above):

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication1
{
   class Program
   {
       static void Main(string[] args)
       {
           Creator();
           //Console.ReadKey();
       }
       static void Creator()
       {
           Random r = new Random((DateTime.Now.DayOfYear + DateTime.Now.Millisecond) * (DateTime.Now.Second + DateTime.Now.Minute + 1));
           string encs = "[{(<>)}]";

           string sb = "";
           for (int i = 0; i < 100; i++)
           {
               sb = "";
               bool good = (r.Next(0, 100) > 50) ? true : false;
               int strlen = r.Next(1, 21) * 2;
               for (int j = 0; j < strlen; j++)
               {
                   if (!good)
                       sb = String.Format("{0}{1}", sb, encs[r.Next(0, encs.Length)]);
                   else
                   {
                       int p = r.Next(0, encs.Length / 2);
                       int q = r.Next(0, 3);
                       if (q == 0)
                           sb = String.Format("{0}{1}{2}", encs[p], sb, encs[encs.Length - p - 1]);
                       else if (q == 1)
                           sb = String.Format("{0}{1}{2}", sb, encs[p], encs[encs.Length - p - 1]);
                       else
                           sb = String.Format("{0}{1}{2}", encs[p], encs[encs.Length - p - 1], sb);
                   }
               }
               //Console.WriteLine(String.Format("{0}: {1}", good, sb.ToString()));
               Console.WriteLine(sb);
           }
       }
   }
}

I couldn't spend that much time on this, as I am at work. Ergo, I'm a little disappointed with the Perl, although it was my first Perl program ever!

I'm particularly curious about how I could have done some sort of recursive check. Please give any suggestions to the Perl script that would make it as close to a one-liner regex check.

~simon