NAME
bsfilt, colcrt - a colcrt-like backspace filter
SYNOPSIS
bsfilt [ - ] [ -U ] [ file ... ]
DESCRIPTION
Bsfilt filters backspace sequences from the input file(s)
(standard input if none) in an approximation of colcrt(1).
Both the backspace and the character it returns to are
removed, unless they form an underline sequence. Underline
sequences are treated according to the settings of the - and
-U options.
OPTIONS
- specifies that no underlining of any kind is to be pro-
pagated. Without this option or the -U option, bsfilt
approximates underlining with minus signs (`-') in fol-
lowing lines.
-U specifies that underlining with underscore (`_') and
backspace (` character sequences is permitted.
SEE ALSO
cawf(1), colcrt(1) and nroff(1).
DIAGNOSTICS
Diagnostic messages are delivered to the standard error
file.
HISTORY
Vic Abell of Purdue University wrote bsfilt to have a back-
space filter for cawf(1) that is independent of licensed
source code.
BUGS
The maximum length of a line that can be underlined with
minus signs is fixed.
Bsfilt does not examine the characters that are being over-
printed via backspace operations. Thus, overprinting that
is intended to form a new character from several different
ones is ineffective and only the last character of the
sequence is propagated - e. g., ``o^H+'', intended to look
like a bullet, is reduced to `+'.