Beefy Boxes and Bandwidth Generously Provided by pair Networks
Just another Perl shrine

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

You're most welcome!

Here's the regex in the grep (with two added features that should be there):

/^\Q$host\E$/; ^ ^ ^^ | | || | | |+ - End of line | | + - End quote metacharacters | + - Begin quote metacharacters (e.g., [.*\+], etc.) + - Match beginning at the start of the line

If you remove the trailing $, it'll match a host name beginning with "db". Try the following with and without the trailing $ in the regex:

use warnings; use strict; my $host = 'db'; while (<DATA>) { print if /^\Q$host\E$/i; } __DATA__ db db4323

Output with $:


This is because if forces an exact match, like $host eq 'db'.

Output without $:

db db4323

This is becuase it's only matching the first two characters of $_ (the default scalar) against the value of $host.

Note that there's the i modifier at the end of the regex. This makes the match case-insensitive, in case you have a host like DB4323.

In reply to Re^5: If conditional checks by Kenosis
in thread If conditional checks by kitkit201

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, 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, 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.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others wandering the Monastery: (2)
    As of 2018-05-26 07:00 GMT
    Find Nodes?
      Voting Booth?