def vol(val):
if val == 'on':
val = 100
elif val == 'off':
val = 0
elif val.isdigit():
val = min(int(val), 100)
val = max(val, 0)
else:
return registered_commands['?']('vol')
if not val:
SoundManager.mute()
return u'已静音。'
else:
SoundManager.unmute()
SoundManager.set_volume(val / 100.0)
return u'音量已设置为 %d' % val
