If you omit the filehandle argument in print, it will default to the last selected filehandle.

Unless you change it, you can expect the current filehandle to be STDOUT. In most cases, print @list and print STDOUT @list mean exactly the same thing; the STDOUT is typically omitted.

You probably won't need to do it very often; however, if you do change the filehandle (with select) you should keep track of the old filehandle, as you'll often need to restore it.

Here's a short script, with output file contents, to demonstrate:

$ perl -e '
    print "Expecting STDOUT\n";
    print STDOUT "Specifying STDOUT\n";
    print STDERR "Specifying STDERR\n";
    print "Current filehandle: ", select(), "\n";
    my $orig_fh = select STDERR;
    print "New filehandle: ", select(), "\n";
    print "Expecting STDERR (after select STDERR)\n";
    select $orig_fh;
    print "Original filehandle: ", select(), "\n";
    print "Expecting STDOUT (after select \$orig_fh)\n";
' 1> x.out 2> x.err

$ cat x.out
Expecting STDOUT
Specifying STDOUT
Current filehandle: main::STDOUT
Original filehandle: main::STDOUT
Expecting STDOUT (after select $orig_fh)

$ cat x.err
Specifying STDERR
New filehandle: main::STDERR
Expecting STDERR (after select STDERR)
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