Path: utzoo!attcan!uunet!decwrl!ucbvax!iwarp.intel.com!news
From: merlyn@iwarp.intel.com (Randal Schwartz)
Newsgroups: comp.lang.perl
Subject: Re: Need $? for open()
Keywords: new feature request
Message-ID: <1990Mar27.163646.16898@iwarp.intel.com>
Date: 27 Mar 90 16:36:46 GMT
References: <23449@pasteur.Berkeley.EDU>
Sender: news@iwarp.intel.com
Reply-To: merlyn@iwarp.intel.com (Randal Schwartz)
Organization: Stonehenge; netaccess via Intel, Beaverton, Oregon, USA
Lines: 39
In-Reply-To: grady@scam.Berkeley.EDU (Steven Grady)

In article <23449@pasteur.Berkeley.EDU>, grady@scam (Steven Grady) writes:
| The problem is that I don't find out if there's an error.  What
| would be really useful is for the "$?" variable (or something
| like it) to be set to the status of the program when it exits.
| Currently, $? is only set by backquoted programs, wait(), and
| system().  Is there any possibility of adding generic open'ed
| commands to this list, or at least some mechanism to provide
| similar functionality?

Already done.  'close' does it.  Quoting from the manpage:

	Closing a pipe explicitly also puts the status value of the
	command into $?.

For example,

	open(TRUE,"true|") || die "Cannot open true... sad but true! ($!)";
	print grep(s/^/true: /, <TRUE>); # show all the output (if any)
	close(TRUE) || die "Cannot close true... very weird ($!)";
	print "true exited with $?\n";
	open(FALSE,"false|") || die "Cannot open false... sad but false! ($!)";
	print grep(s/^/false: /, <FALSE>); # show all the output (if any)
	close(FALSE) || die "Cannot close false... very weird ($!)";
	print "false exited with $?\n";

generates:

	true exited with 0
	false exited with 256

Hope this helps...

$|=1;$_=<<'-- ';s#..#printf"%c",(fork?wait&&$?/256:exit hex($&))#eg;
4a75737420616e6f74686572205065726c206861636b65722c
-- 
/=Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ==========\
| on contract to Intel's iWarp project, Beaverton, Oregon, USA, Sol III      |
| merlyn@iwarp.intel.com ...!any-MX-mailer-like-uunet!iwarp.intel.com!merlyn |
\=Cute Quote: "Welcome to Portland, Oregon, home of the California Raisins!"=/