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| Allegro CL version 9.0 Unrevised from 8.2 to 9.0. 8.2 version

## device-finish-record

Arguments: stream blocking action

Performs record-oriented operations on stream. Simple-streams have a record-end slot that normally has a `nil` value. When the slot is set to a numeric value, it is interpreted by the read or write operation as the location in the buffer of the record-end or break. device-finish-record is then called, and the return value is interpreted based on the action specified and the value of blocking. action is typically one of `:input`, `:output`, or `:prime-input` (see the discussion on "priming" in the second bulleted paragraph below). blocking is a boolean which specifies whether or not the method should block during its operation, or else return immediately.

The return value is either true, meaning success, or `nil`, meaning failure. The interpretation of the `nil` return depends on the value of the blocking argument; if `nil`, then device-finish-record failed to complete the requested task. If blocking was true, then a return of `nil` means an eof was encountered (if action was `:input` or `:prime-input`), or an error occurred (if action was `:output`).

Allegro CL offers calls to device-finish-record under the following circumstances:

- `string-output-simple-stream`: An xp-simple-stream is a subclass of string-output-stream, and thus has character orientation. The pretty printer sets the record-end slot of the xp-simple-stream to the value of `*print-right-margin*`. Then, when that many characters have been output, the device-finish-record method is called which makes formatting decisions about how and where the accumulated output will be sent to the base stream.
- `dual-channel-simple-stream` A socket-simple-stream that might do "chunking" sets the record-end slot to a true value while input chunking is occurring (output-chunking does not use record-orientation, but writes chunks out whenever the buffer becomes full or when force-output or finish-output is called). A special value indicates a "priming", and device-finish-record is called with `:prime-input` as action just before the first character is read. This call causes chunking to temporarily be suspended: bytes are read until the #\return #\linefeed combination, and the bytes read indicate the chunk length. The record-end slot is set based on the chunk length. When the chunk length is reached, device-finish-record is called with `:input` action, which reads bytes and expects a terminating #\return #\linefeed combination. If either of these calls to device-finish-record return `nil`, end-of-file processing is done.

There are no usable methods defined.

See streams.htm for information on the simple-streams implementation in Allegro CL. The older but still supported Gray streams implementation is described in gray-streams.htm.

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This page was not revised from the 8.2 page.
Created 2012.5.30.

|  | ToC | DocOverview | CGDoc | RelNotes | FAQ | Index | PermutedIndex
| Allegro CL version 9.0 Unrevised from 8.2 to 9.0. 8.2 version