how to redirect STDOUT

[redsss]

I want my perl program to print to STDOUT on the console, then redirect so that STDOUT goes into a file, then redirect again so that STDOUT goes to the console. I figured out how to redirect to a file, but I can't figure out how to redirect BACK to the console. HELP!

PS: the reason I have to use STDOUT rather than a different file handle is because I want to execute a system() command that will generate output that goes to STDOUT.

print "printing to screen\n";

open(STDOUT, ">file.txt");    # redirects to file
print "redirected to file\n";

# How do I redirect back to screen?

print "back to screen\n";

 

[btaber]

copy STDOUT before redirect:

#first, dup STDOUT 

open (OLDSTDOUT, "&>STDOUT) or die "Couldn't dup STDOUT: $!"; 

#re-direct STDOUT to log 

open (STDOUT, ">> $logfile") or die "Can't open $logfile: $!"; 

system "$executable"; 

close STDOUT; 

#restore original STDOUT 

open (STDOUT, "&>OLDSTDOUT) or die "Can't restore STDOUT: $!"; 

close OLDSTDOUT;

 

[PaulTEG]

You could use backticks to execute your shell command

@output=`ls -lsa`;
foreach (@output) {
  print "$_\n";
}

HTH
--Paul

 

[rharsh]

btaber has the right idea but the syntax is a bit off:

open (OLDSTDOUT, "[b][red]&>[/red][/b]STDOUT) or die "Couldn't dup STDOUT: $!";
.
.
.
open (STDOUT, "[b][red]&>[/red][/b]OLDSTDOUT) or die "Can't restore STDOUT: $!";

Should read:

open (OLDSTDOUT, "[b][blue]>&[/blue][/b]STDOUT) or die "Couldn't dup STDOUT: $!";
.
.
.
open (STDOUT, "[b][blue]>&[/blue][/b]OLDSTDOUT) or die "Can't restore STDOUT: $!";

 

[toolkit]

How about:

open FILE, ">file" or die;
print "to stdout\n";
$fh = select(FILE);
print "to file\n";
select($fh);
print "to stdout again\n";

Cheers, Neil

 

[redsss]

For my purposes, paulTEG's suggestion will work great. I hadn't thought of using backticks. Thanks everyone!