A couple of things:

1. Use flock() constants defined in Fcntl.pm.
use Fcntl ':flock';
...
flock $fh, LOCK_EX or exit $status;
...

[download]
2. You're redirecting STDOUT and STDERR and then using die(), which will clobber your TEST.NEW if flock() fails. Either don't use die() and just exit() or implement a logging mechanism of some sort so that you're not writing to STDOUT/STDERR.

3. If the file is locked, do you want to exit immediately or do you want the program to block and wait until it's unlocked? 
# will block until file is unlocked
flock $fh, LOCK_EX or exit $status;

# will exit immediately if the file is locked
flock $fh, LOCK_EX | LOCK_NB or exit $status;

[download]
--perlplexer

In reply to Re: File Locking by perlplexer
in thread File Locking by nimdokk

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.