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ANSI Common Lisp  21 Streams 21.2 Dictionary of Streams
| 21.2.22 read-line |
Function |
- Syntax:
-
read-line
&optional input-stream eof-error-p eof-value recursive-p
 line, missing-newline-p
- Arguments and Values:
-
input-stream - an input stream designator.
The default is standard input.
eof-error-p - a generalized boolean.
The default is true.
eof-value - an object.
The default is nil.
recursive-p - a generalized boolean.
The default is false.
line - a string or the eof-value.
missing-newline-p - a generalized boolean.
- Description:
-
Reads from input-stream a line of text
that is terminated by a newline or end of file.
If recursive-p is true,
this call is expected to be embedded in a higher-level call to read
or a similar function used by the Lisp reader.
The primary value, line, is the line that is read,
represented as a string (without the trailing newline, if any).
If eof-error-p is false
and the end of file for input-stream is reached
before any characters are read,
eof-value is returned as the line.
The secondary value, missing-newline-p,
is a generalized boolean that is
false if the line was terminated by a newline,
or true if the line was terminated by
the end of file for input-stream
(or if the line is the eof-value).
- Examples:
-
(setq a "line 1
line2")
"line 1
line2"
(read-line (setq input-stream (make-string-input-stream a)))
"line 1", false
(read-line input-stream)
"line2", true
(read-line input-stream nil nil)
NIL, true
- Affected By:
-
*standard-input*,
*terminal-io*.
- Exceptional Situations:
-
If an end of file2 occurs before any characters are read in the line,
an error is signaled if eof-error-p is true.
- See Also:
-
read
- Notes:
-
The corresponding output function is write-line.
- Allegro CL Implementation Details:
-
None.
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