Hi all,

In the code below, I'm trying to match and capture a small letter character that is flanked by exactly 4 capital letters on its left and right respectively. My regex captures the letter "s" on Line 1 (at position 12) and at Line 2, it captures only the letter "c" (position 6) but not "f" (position 11).

#Each line of $text is independent of the other and not joined as a co
+ntinuous line.
$text = 
q~
adfRadfaUYBGsQWERaeYETEWoyMSn
nbPOIVcRCVVfOOPQbHbnRIIqWweRT
~;

$result = "";

while( $text =~ /[a-z]+[A-Z]{4}([a-z]{1})[A-Z]{4}[a-z]+/g) {
   $result .= $1;
}

print $result; # prints sc but should print scf

[download]

How do I modify my code to match the "f" on the second line that is also flanked by exactly 4 capital letters on its side?

Thanks in anticipation!

In reply to Regex help by Anonymous Monk

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.