Beefy Boxes and Bandwidth Generously Provided by pair Networks
P is for Practical
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
But wait, it gets better again!

You know how you can have that nifty __DATA__ block at the end of your script? It turns out you can lock that too :)

I've used this a number of times and it works just great.

#!/usr/bin/perl

use strict;
use Fcntl 'LOCK_EX', 'LOCK_NB';

unless ( flock DATA, LOCK_EX | LOCK_NB ) {
    print STDERR "Found duplicate script run. Stopping\n";
    exit(0);
}

...

1;





### DO NOT REMOVE THE FOLLOWING LINES ###

__DATA__
This exists to allow the locking code at the beginning of the file to work.
DO NOT REMOVE THESE LINES!


In reply to Re^3: Cron Jobs That Run For Too Long by adamk
in thread Cron Jobs That Run For Too Long by beppu

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 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? | Other CB clients
Other Users?
Others imbibing at the Monastery: (5)
As of 2022-05-17 15:11 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Do you prefer to work remotely?



    Results (66 votes). Check out past polls.

    Notices?