Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
Actually, you aren't matching e-mail addresses. You are simply checking for the existence of the @ symbol. If you know the only lines that contain an @ symbol are e-mail addresses, you're fine.

Fastolfe is correct that a straight match will be faster. The /^.*\@/ is forced to match to the end of the string (or to a newline) and then backtrack to the @ symbol. This is extra overhead and will slow it down.

If you use minimal matching with /^.*?\@/, the regex matches every character (except for newline and end-of-string) and then looks ahead for the @ symbol. Again, you have extra overhead.

A simple scan for the @ symbol (/\@/) just looks for the @ symbol and returns true if found. That is the fastest way to scan for the character. See Death to Dot Star! if you wish to understand more about the dot metacharacters in regexes.


In reply to Re: Regex anchor speed ?: Is /^.*X/ faster than /X/ ? by Ovid
in thread Regex anchor speed ?: Is /^.*X/ faster than /X/ ? by cshirky

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



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others browsing the Monastery: (1)
As of 2024-04-18 04:42 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found