I have the following code which splits a SQL clause into field, operator, and value using a regular expression of alternations composed of known operators. It works fine unless the quoted value in the SQL clause contains an operator character (the equal sign in my example), in which case $val contains 'Response.

I tried adding the usual pattern for quoted strings ("[^"]+") to the front of the regex alternations but that does not help. I tried adding the limit value of ",3" to split but that also does not help. How can I modify my regular expression (variable $opr_regex) to skip quoted values when splitting the SQL clause? 

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

my $clause = qq(failure_reason <> 'Response=X');
my @operators = qw ( <> != !< !> <= >= < > = );
my $opr_regex = '(\s*' . join('\s*|\s*', @operators) . '\s*)';
my ($fld,$opr,$val) = split /$opr_regex/, $clause, 3;

print "\n\$opr_regex =  $opr_regex\n\n";
print "\$clause    =  $clause\n\n";
print "\$fld       = |$fld|\n";
print "\$opr       = |$opr|\n";
print "\$val       = |$val|\n\n";

[download]

"Its not how hard you work, its how much you get done."

In reply to Skip quoted string in regex by roho

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.