O High Masters, I humbly implore you to share your wisdom:

I have apparently gained enough perl knowledge to become a serious threat to myself and others. I am trying to create a program that will fork a number of children, run a subroutine for each child (in parallel), and then, once all the children have returned, tally how many children come back successfully. (return = 1)

My logic is apparently flawed; my code will work as advertised *EXCEPT* the tallying part - each child keeps its own set of variables and I haven't figured out how to get the child to increment a parent variable.

I am constrained to avoid using additional CPAN modules if at all possible, since this has to be rolled out to a large number of client machines..

my $prox = scalar(@targets) -1;

my ($i, $ret, $pid, @pids);
   for ($i = 0; $i <= $prox; $i++) {
       if ($pid=fork) {
           push @pids, $pid;
           waitpid($pid,0);
       } elsif (defined $pid) {
           my $next = @targets[${i}];
           $ret = &check_status($next);
           if ($ret) { $avail ++; }
           exit;
       }
   }

my $success = ( $avail / scalar(@targets) ) * 100;
$success = sprintf('%.2f',$uptime);
print "$success% successful\n";

[download]
Also, I would like to know if there is a way to prevent this from becoming a fork() bomb if the @targets array contains a LOT of targets (it could easily contain 500+ targets), so how do I limit the number of children while still covering all the @targets?

I've looked through the documentation on fork() and wait() and waitpid() and searched this site, but I'm still not finding anything that helps.

I apologize in advance if I'm asking a blind-stupid question, I've been up for too long and my caffeine levels are dangerously low.

Signature void where prohibited by law.

In reply to Tallying results from Forking processes... by Clownburner

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.