using output as stream-name indexer? open-modifiers?
     (&stream-name indexer? open-modifiers?)*
     action

The using output as prefix causes the named streams to be the new current output set during the action contained in the prefix. (Note that the named streams must be currently open.)

Only the following modifiers are permitted with using output as:

1. a string expression containing the element content format modifiers
2. the binary open modifier

Action is the action that falls under the control of the using prefix. If the action contains a %c operator, all the element content indicated by the %c is written to the named streams unless a put, set or another using output as prefix is encountered.

using output as is more useful when a number of actions all write to the same streams.

The following variations are permitted:

• The keyword and can be used in place of "&".
• The list of stream names can be placed in parentheses to improve readability.