cmd,s,a,,,,cache command
pattern,s,h,"*",,,filename pattern
src,s,h,"",,,file or url to cache
fname,s,h,"",,,cache filename
extn,s,h,"",,,cache filename extension
age,i,h,-1,,,file age (in days) to purge
verbose,b,h,no,,,print verbose output?
wait,b,h,yes,,,block on operation?
cache,s,h,"cache$",,,cache directory
