BACKSPACE - back up output unit by one character.

Alternate Entry Name: .BACKS

Usage:

B:
   char = backspace( unit );

C:
   int backspace(FILE *stream);

Description:

BACKSPACE returns the character last written to "unit", and sets things up to write over that character on the next call to PUTCHAR. If an attempt is made to backspace past the beginning of the current line, a '*e' will be returned to "char".

Notes:

A line is flushed to the block image (or device) each time a '*n' is written, leaving the I/O system at the beginning of a new line. Thus it is impossible to backspace over a '*n' (or any other slew character such as '*f', '*r', etc.).

See Also:

expl b lib .seek

expl b lib .tell

Copyright © 1996, Thinkage Ltd.