#compdef dd

if compset -P 1 'conv\='; then
  # If there's a comma present, ignore up to the last one.  The
  # test alone will have that effect.
  compset -p '*,'
  compgen -S, -q \
      -k '(ascii ebcdic ibm block unblock lcase ucase swab noerror sync)'
elif compset -P 1 '[io]f\='; then
  _files
else
  compgen -S '=' -k '(if of ibs obs bs cbs skip files seek count conv)'
fi