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Postings from October 2003
On Mon, Oct 13, 2003 at 09:41:08AM +0100, Doug Sibley wrote:
> http://www.perl.com/doc/manual/html/pod/perlfunc/sleep.html
>
> says "May be interrupted if the process receives a signal such as
> SIGALRM" (as do the O'Reilly series of perl books) which led me to
> believe that I could sleep until I sent a SIGALRM at which point the
> process would continue.
>
> You may wish to update either the behavior or comments of the sleep
> function.
Hmm. It should probably show an example of the usual idiom.
--- pod/perlfunc.pod 2003/10/13 12:11:23 1.1
+++ pod/perlfunc.pod 2003/10/13 12:12:07
@@ -4576,10 +4576,18 @@
=item sleep
Causes the script to sleep for EXPR seconds, or forever if no EXPR.
+Returns the number of seconds actually slept.
+
May be interrupted if the process receives a signal such as C<SIGALRM>.
-Returns the number of seconds actually slept. You probably cannot
-mix C<alarm> and C<sleep> calls, because C<sleep> is often implemented
-using C<alarm>.
+
+ eval {
+ local $SIG{ALARM} = sub { die "Alarm!\n" };
+ sleep;
+ };
+ die $@ unless $@ eq "Alarm!\n";
+
+You probably cannot mix C<alarm> and C<sleep> calls, because C<sleep>
+is often implemented using C<alarm>.
On some older systems, it may sleep up to a full second less than what
you requested, depending on how it counts seconds. Most modern systems
--
Michael G Schwern schwern@pobox.com http://www.pobox.com/~schwern/
Cuius rei demonstrationem mirabilem sane detexi hanc subscriptis
exiguitas non caperet.