87 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
			
		
		
	
	
			87 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
.\"	manual page for bsfilt(1)
 | 
						|
.\"
 | 
						|
.\"
 | 
						|
.\"	Copyright (c) 1991 Purdue University Research Foundation,
 | 
						|
.\"	West Lafayette, Indiana 47907.  All rights reserved.
 | 
						|
.\"
 | 
						|
.\"	Written by Victor A. Abell <abe@mace.cc.purdue.edu>,  Purdue
 | 
						|
.\"	University Computing Center.  Not derived from licensed software;
 | 
						|
.\"	derived from awf(1) by Henry Spencer of the University of Toronto.
 | 
						|
.\"
 | 
						|
.\"	Permission is granted to anyone to use this software for any
 | 
						|
.\"	purpose on any computer system, and to alter it and redistribute
 | 
						|
.\"	it freely, subject to the following restrictions:
 | 
						|
.\"
 | 
						|
.\"	1. The author is not responsible for any consequences of use of
 | 
						|
.\"	   this software, even if they arise from flaws in it.
 | 
						|
.\"
 | 
						|
.\"	2. The origin of this software must not be misrepresented, either
 | 
						|
.\"	   by explicit claim or by omission.  Credits must appear in the
 | 
						|
.\"	   documentation.
 | 
						|
.\"
 | 
						|
.\"	3. Altered versions must be plainly marked as such, and must not
 | 
						|
.\"	   be misrepresented as being the original software.  Credits must
 | 
						|
.\"	   appear in the documentation.
 | 
						|
.\"
 | 
						|
.\"	4. This notice may not be removed or altered.
 | 
						|
.\"
 | 
						|
.TH BSFILT 1 "February, 1991"
 | 
						|
.BY "Purdue University"
 | 
						|
.SH NAME
 | 
						|
bsfilt, colcrt \- a colcrt-like backspace filter
 | 
						|
.SH SYNOPSIS
 | 
						|
.B bsfilt
 | 
						|
[
 | 
						|
.B -
 | 
						|
] [
 | 
						|
.B -U
 | 
						|
] [ file ... ]
 | 
						|
.SH DESCRIPTION
 | 
						|
.I Bsfilt
 | 
						|
filters backspace sequences from the input \fIfile\fR(s)
 | 
						|
(standard input if none)
 | 
						|
in an approximation of
 | 
						|
.IR 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
 | 
						|
.B \-
 | 
						|
and
 | 
						|
.B \-U
 | 
						|
options.
 | 
						|
.SH OPTIONS
 | 
						|
.TP
 | 
						|
.B \-
 | 
						|
specifies that no underlining of any kind is to be propagated.
 | 
						|
Without this option or the
 | 
						|
.B \-U
 | 
						|
option,
 | 
						|
.I bsfilt
 | 
						|
approximates underlining with minus signs (`-') in following lines.
 | 
						|
.TP
 | 
						|
.B \-U
 | 
						|
specifies that underlining with underscore (`_') and backspace (`\b')
 | 
						|
character sequences is permitted.
 | 
						|
.SH SEE ALSO
 | 
						|
cawf(1), colcrt(1) and nroff(1).
 | 
						|
.SH DIAGNOSTICS
 | 
						|
Diagnostic messages are delivered to the standard error file.
 | 
						|
.SH HISTORY
 | 
						|
Vic Abell of Purdue University wrote
 | 
						|
.I bsfilt
 | 
						|
to have a backspace filter for
 | 
						|
.IR cawf (1)
 | 
						|
that is independent of licensed source code.
 | 
						|
.SH BUGS
 | 
						|
The maximum length of a line that can be underlined with minus signs is
 | 
						|
fixed.
 | 
						|
.LP
 | 
						|
.I Bsfilt
 | 
						|
does not examine the characters that are being overprinted 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 `+'.
 |