Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

Comment on

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

There are many ways to ensure single instance of perl program is running. PID files are the traditional way to do it. we can also hold a lock on a file,for example the program itself. This small piece of code will do the trick:

use Fcntl ':flock'; open my $self, '<', $0 or die "Couldn't open self: $!"; flock $self, LOCK_EX | LOCK_NB or croak "This script is already runnin +g";

One advantage over PID files is that files automatically get unlocked when the program exits. It is much easier to implement in a reliable way.


All is well

In reply to Re: Check for another running instance of the same program by vinoth.ree
in thread Check for another running instance of the same program by Narveson

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!
  • 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
  • Outside of code tags, you may need to use entities for some characters:
            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?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others chilling in the Monastery: (11)
    As of 2014-09-19 17:37 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      How do you remember the number of days in each month?











      Results (143 votes), past polls