[ILUG] basic fft processing ?

[Declan Grady]

Hi,
I'm trying to find some fft proggies, and have googled for ages.
I've found loads of info on fft and even some c++ functions, but I'm no
programmer, so I'm a bit lost :(

I have a wav file, converted (using sox) to a stream of data in the time
domain, and now I need to process this through a fft to give a file of
frequency versus amplitude, for graphing with gnuplot.

I'm sure it probably quite simple, but I cant see the wood for the trees !

Any pointers ?  
Is there a command like 'fft --options input.dat >output.dat' ?

Thanks,
Declan