Start by not using a global var (*SNMP). If you insist, at least localize it. If it ceases to exist, it's hard for it to be "jammed".

Fixed along with *many* other problems: 

sub {
    my ($target, $table, $fieldstring, $comstr) = @_;

    my @cmd = ( mibtable => (
        -table  => $table,
        -fields => $fieldstring,
        -node   => $target,
    );

    open(my $fr_child, '-|', @cmd)
        or die("Can't launch $cmd[0]: $!\n");

    while (<$fr_child>) {
        # do stuff
    }

    close($fr_child)
        or die("Can't wait for child: $!\n");

    die("Child died from signal ", ($? & 0x7F), "\n") if $? & 0x7F;
    die("Child died with code ",   ($? >> 8),   "\n") if $? >> 8;

    print("Child exited successfully\n");
}

[download]

In reply to Re: Jammed FH pipe by ikegami
in thread Jammed FH pipe by gryf

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.