in reply to Reopening STDOUT

There are several ways to do this.

1. My favorite, localize STDOUT in a block, 

{
    open local(*STDOUT), '>', '/dev/null' or die $!;
   #...
    close STDOUT or die $!;
}
# STDOUT is restored here

[download]

2. Open a different filehandle and select it to be the default output filehandle, 

open NIL, '>', '/dev/null' or die $!;
select NIL;
#...
select STDOUT;
close NIL or die $!;

[download]

3. Duplicate STDOUT to some other handle *OLDSO, open STDOUT, print things, close STDOUT, duplicate *OLDSO to STDOUT, close *OLDSO. I don't like this one, too fussy.

After Compline,
Zaxo

Replies are listed 'Best First'.
Re^2: Reopening STDOUT ([open])
by tye (Sage) on Oct 10, 2003 at 20:45 UTC

    Your favorite trick can break some things. I just avoid copying or localizing globs that contain open file handles as I find there are too many egde cases where things break.

    I much prefer to use the technique documented directly in the open documentation. Here is a modified version of it that doesn't bother with STDERR: 

    open( OLDOUT, ">&STDOUT" );
open( STDOUT, '> foo.out' )
    or  die "Can't redirect STDOUT to foo.out: $!\n";

# this works for subprocesses and C code too:
print "stdout 1\n";

close( STDOUT );
open( STDOUT, ">&OLDOUT" );
close( OLDOUT );

    [download]
    You can use a non-bareword file handle in place of OLDOUT, if you prefer.

                    - tye
[reply]
[d/l]
[select]
      ...as I find there are too many egde cases where things break.

      Such as?

[reply]

In Section Seekers of Perl Wisdom