PERL Beginners - Redirecting file handler to STDOUT

Author

Redirecting file handler to STDOUT

Ben Edwards

2007-06-22, 7:59 am

I am opening a log file:

open( LOGFILE, ">>cronlog.txt" );

This is being written to in lots of places.

I have been asked to change the program so if -m (manual) flag is
passed the stuff that goes to the log file is send to standard out
instead. Is it possible to change the above command to redirect
LOGFILE to STDOUT (i.e. make the two the same thing.

i.e.

if ( defined( $opt_m ) ) {
open( LOGFILE, STDOUT );
} else {
open( LOGFILE, ">>cronlog.txt" );
}

I even tried:

LOGFILE = STDOUT;

But I get:

Bareword "STDOUT" not allowed while "strict subs" in use

Whjenever I try to use STDOUT;(

Any ideas?
Ben
--
Ben Edwards - Bristol, UK
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Xavier Noria

2007-06-22, 7:59 am

On Jun 22, 2007, at 11:57 AM, Ben Edwards wrote:

> I am opening a log file:
>
> open( LOGFILE, ">>cronlog.txt" );
>
> This is being written to in lots of places.
>
> I have been asked to change the program so if -m (manual) flag is
> passed the stuff that goes to the log file is send to standard out
> instead. Is it possible to change the above command to redirect
> LOGFILE to STDOUT (i.e. make the two the same thing.

Given those requirements, a simple solution would be:

unless (m_flag_given) {
open my $fh, '>>cronlog.txt' or die $!;
select $fh;
}

# the rest of the program uses regular prints

-- fxn

Paul Lalli

2007-06-22, 7:59 am

On Jun 22, 5:57 am, funkyt...@gmail.com (Ben Edwards) wrote:
> I am opening a log file:
>
> open( LOGFILE, ">>cronlog.txt" );
>
> This is being written to in lots of places.
>
> I have been asked to change the program so if -m (manual) flag is
> passed the stuff that goes to the log file is send to standard out
> instead. Is it possible to change the above command to redirect
> LOGFILE to STDOUT (i.e. make the two the same thing.
>
> i.e.
>
> if ( defined( $opt_m ) ) {
> open( LOGFILE, STDOUT );} else {
>
> open( LOGFILE, ">>cronlog.txt" );
>
> }
>
> I even tried:
>
> LOGFILE = STDOUT;
>
> But I get:
>
> Bareword "STDOUT" not allowed while "strict subs" in use
>
> Whjenever I try to use STDOUT;(

Because this is the equivalent of saying
"LOGFILE" = "STDOUT";
which obviously makes no sense, so by using strict such things are
prevented.

You can however assign the typeglob *LOGFILE to *STDOUT:

if (defined( $opt_m) ) {
*LOGFILE = *STDOUT;
}

Paul Lalli

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