UNGETBYTE
Syntax UNGETBYTE
 
Explanation UNGETBYTE pushes the ASCII character corresponding to its input onto the input stream so that the next character input primitive will pick up the character. Only one character can be pushed back at a time, so the character must be removed from the input stream before UNGETBYTE can be used again.

See also ASCII, GETBYTE, PEEKBYTE, and PUTBYTE.
 
Examples The following procedure removes empty lines from the input stream and sends all other information to the output stream.

TO SKIP.EMPTY.LINES
     MAKE "FIRST.CHAR.ON.LINE GETBYTE 
     TEST :FIRST.CHAR.ON.LINE = 13 
     IFF [UNGETBYTE :FIRST.CHAR.ON.LINE PR READLINE]
     SKIP.EMPTY.LINES
END

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