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STDIN STDOUT?

Posted on 2000-02-17
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Last Modified: 2008-02-26
According to a "teach yourself Perl" book I've got here, I can reset STDOUT to the default (ie. normal STDOUT) by doing this :

open(STDOUT,">-");

However, if I do this :

print "Hello1\n";
open(STDOUT,">/dev/null");
print "Hello2\n";
open(STDOUT,">-");
print "Hello3\n";

I'd expect to see :
Hello1
Hello3

however all I see is :
Hello1

I need to system() a process which refuses to run quietly (even with direction to /dev/null) so I want Perl to turn off stdout temporarily, but then I need it back....hayelp!
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Question by:ptruman
2 Comments
 
LVL 16

Accepted Solution

by:
maneshr earned 150 total points
ID: 2531860
try this. it works


#!/usr/local/bin/perl

open(STDOUT,">-");
print "Hello1\n";
close(STDOUT);
open(STDOUT,">/dev/null");
print "Hello2\n";
close(STDOUT);
open(STDOUT,">-");
print "Hello3\n";
close(STDOUT);
0
 
LVL 85

Expert Comment

by:ozo
ID: 2531881
print "Hello1\n";
open(OLDOUT, ">&STDOUT");
open(STDOUT,">/dev/null");
print "Hello2\n";
open(STDOUT, ">&OLDOUT");
print "Hello3\n";
#see `perldoc -f open` and `perldoc -q STDERR`
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