====== Function READ-LINE ====== ====Syntax==== * **read-line** ''&optional'' //input-stream// //eof-error-p// //eof-value// //recursive-p// → //line//, //missing-newline-p// ====Arguments and Values==== * //input-stream// - an //[[CL:Glossary:input]]// //[[CL:Glossary:stream designator]]//. The default is //[[CL:Glossary:standard input]]//. * //eof-error-p// - a //[[CL:Glossary:generalized boolean]]//. The default is //[[CL:Glossary:true]]//. * //eof-value// - an //[[CL:Glossary:object]]//. The default is **[[CL:Constant Variables:nil]]**. * //recursive-p// - a //[[CL:Glossary:generalized boolean]]//. The default is //[[CL:Glossary:false]]//. * //line// - a //[[CL:Glossary:string]]// or the //eof-value//. * //missing-newline-p// - a //[[CL:Glossary:generalized boolean]]//. ====Description==== Reads from //input-stream// a line of text that is terminated by a //[[CL:Glossary:newline]]// or //[[CL:Glossary:end of file]]//. If //recursive-p// is //[[CL:Glossary:true]]//, this call is expected to be embedded in a higher-level call to **[[CL:Functions:read]]** or a similar //[[CL:Glossary:function]]// used by the //[[CL:Glossary:Lisp reader]]//. The //[[CL:Glossary:primary value]]//, //line//, is the line that is read, represented as a //[[CL:Glossary:string]]// (without the trailing //[[CL:Glossary:newline]]//, if any). If //eof-error-p// is //[[CL:Glossary:false]]// and the //[[CL:Glossary:end of file]]// for //input-stream// is reached before any //[[CL:Glossary:character|characters]]// are read, //eof-value// is returned as the //line//. The //[[CL:Glossary:secondary value]]//, //missing-newline-p//, is a //[[CL:Glossary:generalized boolean]]// that is //[[CL:Glossary:false]]// if the //line// was terminated by a //[[CL:Glossary:newline]]//, or //[[CL:Glossary:true]]// if the //line// was terminated by the //[[CL:Glossary:end of file]]// for //input-stream// (or if the //line// is the //eof-value//). ====Examples==== <blockquote> ([[CL:Macros:defparameter]] *a* "line 1 line 2") <r>"line 1 line 2" </r> ([[CL:Macros:defparameter]] *input-stream* ([[CL:Functions:make-string-input-stream]] *a*)) (read-line *input-stream*) <r>"line 1" //[[CL:Glossary:false]]// </r> (read-line *input-stream*) <r>"line2" //[[CL:Glossary:true]]// </r> (read-line *input-stream* [[CL:Constant Variables:nil]] [[CL:Constant Variables:nil]]) <r>[[CL:Constant Variables:NIL]] //[[CL:Glossary:true]]// </r> </blockquote> ====Side Effects==== None. ====Affected By==== **[[CL:Variables:star-standard-input-star|*standard-input*]]**, **[[CL:Variables:star-terminal-io-star|*terminal-io*]]**. ====Exceptional Situations==== If an //[[CL:Glossary:end of file]]// occurs before any characters are read in the line, an error is signaled if //eof-error-p// is //[[CL:Glossary:true]]//. ====See Also==== * **[[CL:Functions:read|Function READ]]** ====Notes==== The corresponding output function is **[[CL:Functions:write-line]]**. \issue{ARGUMENTS-UNDERSPECIFIED:SPECIFY}