hello, below is a code which logic is unexplicable to me: 
#!/bin/perl -w
$p= "horraen=sumsel\[13\]\)\n";
$m="sumsel\[13\]";
print join("","this is \$m:",$m,"\n");
print $p;
if ($p=~m/en=$m\)/) {print "yeah!\n";}
else {print "why isn't it matching?\n";}
$m=~s/\[/\\\[/g;
$m=~s/\]/\\\]/g;
print join("","this is \$m:",$m,"\n");
if ($p=~m/en=$m\)/) {print "yeah!\n";}
else {print "what will I do now?\n";}

[download]
Why do I need the add an addition "\\" before the sqare braces (in the substring) when matching the substring? -ISAI student

In reply to regexp matching with "\[" in the substring to be matched by ISAI student

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.