I read with interest, a thread started by Nitrox over 4 yrs ago, about detecting whether there is another copy of a script already running. If I am only needing to run on a Linux system, are there any disadvantages to doing something like this instead of using locks as described in that thread? 
sub ProcessRunning {

#  If the passed string exists in the current Unix/Linux process list,
#  then this subroutine returns the lines from a "ps -e" command which
#  contain that string.   These lines will look something like
#  "26787 pts/1    00:00:00 TestLoop.pl".  If more than one running
#  process line contains that string, each of those lines will be
#  included in the returned value.  Since this is Perl, these
#  returned values can be treated as TRUE if desired.
#  Make sure to specify a string that will uniquely locate the
#  processes of interest. Alternatively, the returned value could then
#  be further examined for other analysis.
#
#  If the string does NOT exist, an empty value is returned, which
#  can be treated as FALSE.
#
#  Sample usages:
#     exit if &ProcessRunning($myProcess);
#  OR
#     &ProcessRunning($myProcess) and die 
#       "Another copy of process $myProcess is already running\n";
#  OR
#     $result = &ProcessRunning($myProcess);  # Examine $result for
                                              # further processing

  return 0 unless (`ps -e | grep @_ | grep -v grep`);

} # end sub ProcessRunning

[download]

In reply to Process Already Running by Photius

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.