re-opening pipes

[Alan Drew]

I am using perl to pipe commands to a compiled binary (long story - 
35,000 lines of badly written fortran, with an equally badly written 
user interface - and not written by me!). I am using Filehandle to open 
the pipe in perl, but there are occasions when I want to restart the 
binary (i.e close the pipe and open it again) without restarting the 
perl script. I am a relative newbie to perl, so please don't get too 
upset if the answer is an easy one!
Al.