MidLifeXis already answered your question with

   last if $char_read =~ /\s/;
[download]

but I thought I would add that since you're not familiar with regular expressions, you might find the excellent 'perldocs' documentation that's included with Perl helpful in learning about regular expressions and pattern matching.

Do

   perldoc perl
[download]

at a command prompt, and you'll see all the different perldocs that come with perl. Listed there are these regular expression topics:

           perlrequick         Perl regular expressions quick start
           perlretut           Perl regular expressions tutorial
           perlre              Perl regular expressions, the rest of t
+he story
[download]

So, then to read the perldocs on perlrequick, you would do

   perldoc perlrequick
[download]

Hope this helps.