sub is_valid_re {
    eval { qr/$_[0]/ };
    return $@ ? 'NO' : 'YES';
}

[download]

This eval returns a regex or undef, so you could write as follows: 

sub is_valid_re { eval { qr/$_[0] } ? 'YES' : 'NO' }

[download]
But I'd _never_ return words when a boolean value is needed. Digits are so much nicer for that. If you want words, you could create yet another sub to turn the truth number into a word. 
sub is_valid_re { eval { qr/$_[0] } }
print is_valid_re('abc') ? 'YES' : 'NO';

sub human_bool { shift ? 'YES' : 'NO' }
print human_bool(is_valid_re('abc'));

[download]

- Yes, I reinvent wheels.
- Spam: Visit eurotraQ.

In reply to Re: Re: Validating a Regexp by Juerd
in thread Validating a Regexp by PetaMem

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.