It's been 11 years since I've used an AIX machine, but if i remember correctly binding a socket to a specific port works on AIX (and every other OS i've ever tried)... 

#!/usr/bin/perl -l

use warnings;
use strict;
use Socket;

my $sock_fh;

BEGIN {
    my $port = 987654; # any constant specific to this app
    socket($sock_fh, PF_INET, SOCK_STREAM, getprotobyname('tcp'))
    or die "socket: $!";
    bind($sock_fh, sockaddr_in($port, INADDR_LOOPBACK))
    or (warn "another process is already running ($!)\n"
        and exit(1));
}

# BEGIN: where you do your work
print "send interupt to kill process";
while (<>) {
    sleep 1; 
}
# END: where you do your work

END {
    $sock_fh->close() if defined $sock_fh;
}

[download]

In reply to Re: Lightweight Solution To "Only 1 Process Running" On AIX by hossman
in thread Lightweight Solution To "Only 1 Process Running" On AIX by Limbic~Region

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.