perldoc perlipc 

       You may also choose to assign the strings 'IGNORE' or 'DEFAULT'
+ as the
       handler, in which case Perl will try to discard the signal or d
+o the default
       thing.

       On most Unix platforms, the "CHLD" (sometimes also known as "CL
+D") signal
       has special behavior with respect to a value of 'IGNORE'.  Sett
+ing
       $SIG{CHLD} to 'IGNORE' on such a platform has the effect of not
+ creating
       zombie processes when the parent process fails to "wait()" on i
+ts child
       processes (i.e. child processes are automatically reaped).  Cal
+ling
       "wait()" with $SIG{CHLD} set to 'IGNORE' usually returns "-1" o
+n such platforms.

[download]

In reply to Re^3: Perl script to wait for a program to finish by jwkrahn
in thread Perl script to wait for a program to finish by renzosilv

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.