How can I write metadata to AIFF files in terminal, I'd like to write the 'track number' field of ID3.
Phil Harvey's exiftool is a great tool for reading and writing metadata. It requires that you have perl installed. You may need to compile exiftool ( I'm not sure whether compiled binaries are available) Once installed just enter
perldoc exiftool
The manual is well written.
I have researched exiftool and it is read only for ID3 in AIFF files. I need to write 
ExifTool Tag Names