Programming Perl

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The Standard Perl Library
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7.2.54 SelectSaver - Save and Restore Selected Filehandle

use SelectSaver;

select $fh_old;
{
    my $saver = new SelectSaver($fh_new); # selects $fh_new
}
# block ends; object pointed to by "my" $saver is destroyed
# previous handle, $fh_old is now selected

# alternative invocation, without filehandle argument
my $saver = new SelectSaver; # selected filehandle remains unchanged

A SelectSaver object contains a reference to the filehandle that was selected when the object was created. If its new() method is given a filehandle as an argument, then that filehandle is selected; otherwise, the selected filehandle remains unchanged.

When a SelectSaver object is destroyed, the filehandle that was selected immediately prior to the object's creation is re-selected.


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