read-line &optional input-stream eof-error-p eof-value recursive-p
=> line, missing-newline-p
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.
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).
(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
If an end of file occurs before any characters are read in the line, an error is signaled if eof-error-p is true.
The corresponding output function is write-line.