or download this
As a special case the 3-arg form with a read/write mode and the third
+argument being "undef":
open(TMP, "+>", undef) or die ...
...
opens a filehandle to an anonymous temporary file. Also using "+
+<" works for symmetry,
but you really should consider writing something to the temporary
+ file first. You will need
to seek() to do the reading.