open(FH, '>', $filename) or die "cannot open file";
select FH;  # make print() use FH by default
...
close FH;  # close the filehandle print() is using by default
...
# try to print() to closed FH by default (no other filehandle specified
# for print(), no other open filehandle has been select()-ed)
print "Three Rings for the Elven-kings under the sky,\n";
# warning: "print() on closed filehandle FH at ..."