Hi,

In message "Re: How to call system having trap("CHLD", "IGNORE")?"
    on Tue, 18 Jul 2006 20:26:38 +0900, "Robert Dober" <robert.dober / gmail.com> writes:

|Hmm I conclude from your reply (and tested)
|trap('CHILD', 'IGNORE') and
|trap('CHILD'){ nil }
|do not have the same semantics.

No they don't.  The former ignores SIGCHLD.  The latter handles
SIGCHLD and invokes empty signal handler.