set_stream/2

Availability:built-in

set_stream(+Stream, +Attribute)

Modify an attribute of an existing stream. Attribute specifies the stream property to set. If stream is a pair (see stream_pair/3) both streams are modified, unless the property is only meaningful on one of the streams or setting both is not meaningful. In particular, eof_action only applies to the read stream, representation_errors only applies to the write stream and trying to set alias or line_position on a pair results in a permission_error exception. See also stream_property/2 and open/4.

alias(AliasName): Set the alias of an already created stream. If AliasName is the name of one of the standard streams, this stream is rebound. Thus, set_stream(S, current_input) is the same as set_input/1, and by setting the alias of a stream to user_input, etc., all user terminal input is read from this stream. See also interactor/0.
buffer(Buffering): Set the buffering mode of an already created stream. Buffering is one of full, line or false.
buffer_size(+Size): Set the size of the I/O buffer of the underlying stream to Size bytes.
close_on_abort(Bool): Determine whether or not the stream is closed by abort/0. By default, streams are closed.
close_on_exec(Bool): Set the close_on_exec property. See stream_property/2.
encoding(Atom): Defines the mapping between bytes and character codes used for the stream. See section 2.19.1 for supported encodings. The value bom causes the stream to check whether the current character is a Unicode BOM marker. If a BOM marker is found, the encoding is set accordingly and the call succeeds. Otherwise the call fails.
eof_action(Action): Set end-of-file handling to one of eof_code, reset or error.
file_name(FileName): Set the filename associated to this stream. This call can be used to set the file for error locations if Stream corresponds to FileName and is not obtained by opening the file directly but, for example, through a network service.
line_position(LinePos): Set the line position attribute of the stream. This feature is intended to correct position management of the stream after sending a terminal escape sequence (e.g., setting ANSI character attributes). Setting this attribute raises a permission error if the stream does not record positions. See line_position/2 and stream_property/2 (property position).
locale(+Locale): Change the locale of the stream. See section 4.23.
newline(NewlineMode): Set input or output translation for newlines. See corresponding stream_property/2 for details. In addition to the detected modes, an input stream can be set in mode detect. It will be set to dos if a \r character was removed.
timeout(Seconds): This option can be used to make streams generate an exception if it takes longer than Seconds before any new data arrives at the stream. The value infinite (default) makes the stream block indefinitely. Like wait_for_input/3, this call only applies to streams that support the select() system call. For further information about timeout handling, see wait_for_input/3. The exception is of the form
error(timeout_error(read, Stream), _)
type(Type): Set the type of the stream to one of text or binary. See also open/4 and the encoding property of streams. Switching to binary sets the encoding to octet. Switching to text sets the encoding to the default text encoding.
record_position(Bool): Do/do not record the line count and line position (see line_count/2 and line_position/2). Calling set_stream(S, record_position(true)) resets the position the start of line 1.
representation_errors(Mode): Change the behaviour when writing characters to the stream that cannot be represented by the encoding. See also stream_property/2 and section 2.19.1.
tty(Bool): Modify whether Prolog thinks there is a terminal (i.e. human interaction) connected to this stream. On Unix systems the initial value comes from isatty(). On Windows, the initial user streams are supposed to be associated to a terminal. See also stream_property/2.