Rafael Garcia-Suarez <[EMAIL PROTECTED]> writes:
> Change 24194 by [EMAIL PROTECTED] on 2005/04/07 12:42:07
>
> Mention that select() returns -1 on error,
> as suggested by Hernan Perez Masci
Hmmm, returning a TRUE value on failure is quite unperlish. I wonder
how much software got this wrong? For instance among the core modules
we find code like this.
Net:::Cmd:
if (select($rout=$rin, undef, undef, $timeout)) {
sysread($cmd, $buf="", 1024)
...
}
else {
# timeout
...
}
Net::Ping:
$nfound = mselect((my $rout=$rbits), undef, undef, $timeout); # Wait for
packet
$timeout = $finish_time - &time(); # Get remaining time
if (!defined($nfound)) # Hmm, a strange error
{
$ret = undef;
$done = 1;
}
elsif ($nfound) # Got a packet from somewhere
{
...
} else { # Oops, timed out
$done = 1;
}
> Affected files ...
>
> ... //depot/perl/pod/perlfunc.pod#461 edit
>
> Differences ...
>
> ==== //depot/perl/pod/perlfunc.pod#461 (text) ====
> Index: perl/pod/perlfunc.pod
> --- perl/pod/perlfunc.pod#460~24100~ Wed Mar 30 05:16:52 2005
> +++ perl/pod/perlfunc.pod Thu Apr 7 05:42:07 2005
> @@ -4603,6 +4603,9 @@
> is implementation-dependent. See also L<perlport> for notes on the
> portability of C<select>.
>
> +On error, C<select> behaves like the select(2) system call : it returns
> +-1 and sets C<$!>.
> +
> B<WARNING>: One should not attempt to mix buffered I/O (like C<read>
> or <FH>) with C<select>, except as permitted by POSIX, and even
> then only on POSIX systems. You have to use C<sysread> instead.
> End of Patch.
