[PATCH] Add open "|-" and open "-|" to perlopentut

[Shlomi Fish <shlomif@iglu.org.il>]

This patch documents open "|-" and open "-|" in perlopentut. It is against 
bleadperl.

Regards,

	Shlomi Fish

-----------------------------------------------------------------
Shlomi Fish       http://www.shlomifish.org/
Understand what Open Source is - http://xrl.us/bjn82

Shlomi, so what are you working on? Working on a new wiki about unit testing 
fortunes in freecell? -- Ran Eilam
--- pod/perlopentut.pod.orig	2008-08-24 23:03:59.712932993 +0300
+++ pod/perlopentut.pod	2008-08-24 23:23:12.339272053 +0300
@@ -165,6 +165,32 @@
 library will handle this for you.  Check out 
 L<perlipc/"Bidirectional Communication with Another Process">
 
+perl-5.6.x introduced a version of piped open that executes a process
+based on its command line arguments without relying on the shell. (Similar
+to L<perlfunc/"system">'s C<system(@LIST)> notation.) This is safer and
+faster than executing a single argument pipe-command, but does not allow
+special shell constructs.
+
+Here's an example of C<open "-|">, which prints a random Unix
+fortune cookie as uppercase:
+
+    my $collection = shift(@ARGV);
+    open my $fortune, "-|", "fortune", $collection
+        or die "Could not find fortune";
+    while (<$fortune>)
+    {
+        print uc($_);
+    }
+    close($fortune);
+
+And this C<open "|-"> pipes into md5sum:
+
+    open my $pipe, "|-", "md5sum"
+        or die "Could not execute md5sum";
+    print {$pipe} "Hi there!\n";
+    print {$pipe} "Non-random string.\n";
+    close($pipe);
+
 =head2 The Minus File
 
 Again following the lead of the standard shell utilities, Perl's

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