Redirecting STDERR to STDOUT with UTF8 layer

There's a bit of a gotcha involved with redirecting filehandles when layers are involved. What I wanted to do was:

Redirect STDOUT to a file, with the :utf8 layer
Redirect STDERR to STDOUT (assuming STDOUT's :utf8 layer would still apply)

I found that text going to STDOUT was correctly UTF8 encoded, but text going to STDERR wasn't.

You need to add the :utf8 layer to STDERR separately. As far as I can see, there is no way of combining layers with redirection in the same open statement. Instead, you need to use binmode on STDERR after redirecting it to STDOUT.

    #!/usr/bin/perl
    use strict;
    use warnings;

    my $utf8="\xe9";

    close (STDOUT);
    open( STDOUT, ">>:utf8", 'test.txt' ) or die $!;
    close STDERR;
    open( STDERR, ">>&STDOUT" ) or die $!;

    print        ("STDOUT: ",$utf8,"\n");
    print STDERR ("STDERR: ",$utf8,"\n");

    binmode (STDERR,':utf8');
    print STDERR ("STDERR with binmode: ",$utf8,"\n");
    
    
PRINTS:

    STDOUT: é
    STDERR: \xe9            (not literally - prints character \xe9, no
+t UTF-8 encoded)
    STDERR with binmode: é
[download]

Clint

(thanks to tye and Joost for helping me figure this out)

Update: Filed as bug 44701

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Re: Redirecting STDERR to STDOUT with UTF8 layer by clinton (Priest) on Aug 16, 2007 at 12:39 UTC
Something else I've noticed. According to perlfunc, if you try to re-open STDOUT or STDERR as an "in memory" file, you have to close it first, implying that if you want to re-open it to as a file, you DON'T need to close it first. However, if you don't close it first, then the ':utf8' layer won't be applied: `#!/usr/bin/perl use strict; use warnings; my $utf8="\xe9"; open STDOUT, ">>:utf8", 'test.txt' or die $!; print "No close: ",$utf8,"\n"; close STDOUT; open STDOUT, ">>:utf8", 'test.txt' or die $!; print "Close: ",$utf8,"\n"; PRINTS: No close: \xe9 (not literally - prints character \xe9, not UTF- +8 encoded) Close: é` [download] Clint Update: Filed as bug 44703	[reply] [d/l]

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Re: Redirecting STDERR to STDOUT with UTF8 layer
by clinton (Priest) on Aug 16, 2007 at 12:39 UTC

perlfunc

if you try to re-open STDOUT or STDERR as an "in memory" file, you have to close it first

However, if you don't close it first, then the ':utf8' layer won't be applied:


    #!/usr/bin/perl
    use strict;
    use warnings;

    my $utf8="\xe9";

    open STDOUT, ">>:utf8", 'test.txt'  or die $!;
    print "No close: ",$utf8,"\n";

    close STDOUT;
    open STDOUT, ">>:utf8", 'test.txt'  or die $!;
    print "Close: ",$utf8,"\n";


PRINTS:
    No close: \xe9    (not literally - prints character \xe9, not UTF-
+8 encoded)
    Close: é
[download]

Clint

Update: Filed as bug 44703

[reply]
[d/l]