1994-05-27 12:33:43 +00:00
|
|
|
.\" Copyright (c) 1989, 1991, 1993, 1994
|
|
|
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
|
|
|
.\"
|
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
|
.\" are met:
|
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
|
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
|
.\" This product includes software developed by the University of
|
|
|
|
|
.\" California, Berkeley and its contributors.
|
|
|
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
|
|
|
.\" may be used to endorse or promote products derived from this software
|
|
|
|
|
.\" without specific prior written permission.
|
|
|
|
|
.\"
|
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
|
.\"
|
|
|
|
|
.\" @(#)vis.1 8.4 (Berkeley) 4/19/94
|
1999-08-28 01:08:13 +00:00
|
|
|
.\" $FreeBSD$
|
1994-05-27 12:33:43 +00:00
|
|
|
.\"
|
2004-06-24 16:08:02 +00:00
|
|
|
.Dd June 25, 2004
|
1994-05-27 12:33:43 +00:00
|
|
|
.Dt VIS 1
|
2001-07-10 14:16:33 +00:00
|
|
|
.Os
|
1994-05-27 12:33:43 +00:00
|
|
|
.Sh NAME
|
|
|
|
|
.Nm vis
|
|
|
|
|
.Nd display non-printable characters in a visual format
|
|
|
|
|
.Sh SYNOPSIS
|
1997-08-25 06:37:37 +00:00
|
|
|
.Nm
|
1994-05-27 12:33:43 +00:00
|
|
|
.Op Fl cbflnostw
|
|
|
|
|
.Op Fl F Ar foldwidth
|
1997-08-25 06:37:37 +00:00
|
|
|
.Op Ar
|
1994-05-27 12:33:43 +00:00
|
|
|
.Sh DESCRIPTION
|
2002-04-20 12:18:28 +00:00
|
|
|
The
|
|
|
|
|
.Nm
|
|
|
|
|
utility is a filter for converting non-printable characters
|
2004-07-02 22:22:35 +00:00
|
|
|
into a visual representation.
|
|
|
|
|
It differs from
|
1994-05-27 12:33:43 +00:00
|
|
|
.Ql cat -v
|
|
|
|
|
in that
|
2004-07-02 22:22:35 +00:00
|
|
|
the form is unique and invertible.
|
|
|
|
|
By default, all non-graphic
|
1994-05-27 12:33:43 +00:00
|
|
|
characters except space, tab, and newline are encoded.
|
|
|
|
|
A detailed description of the
|
|
|
|
|
various visual formats is given in
|
|
|
|
|
.Xr vis 3 .
|
|
|
|
|
.Pp
|
|
|
|
|
The options are as follows:
|
|
|
|
|
.Bl -tag -width Ds
|
|
|
|
|
.It Fl b
|
|
|
|
|
Turns off prepending of backslash before up-arrow control sequences
|
2004-07-02 22:22:35 +00:00
|
|
|
and meta characters, and disables the doubling of backslashes.
|
|
|
|
|
This
|
1994-05-27 12:33:43 +00:00
|
|
|
produces output which is neither invertible or precise, but does
|
2004-07-02 22:22:35 +00:00
|
|
|
represent a minimum of change to the input.
|
|
|
|
|
It is similar to
|
1994-05-27 12:33:43 +00:00
|
|
|
.Dq Li cat -v .
|
|
|
|
|
.It Fl c
|
|
|
|
|
Request a format which displays a small subset of the
|
|
|
|
|
non-printable characters using C-style backslash sequences.
|
|
|
|
|
.It Fl F
|
|
|
|
|
Causes
|
1997-08-25 06:37:37 +00:00
|
|
|
.Nm
|
1994-05-27 12:33:43 +00:00
|
|
|
to fold output lines to foldwidth columns (default 80), like
|
|
|
|
|
.Xr fold 1 ,
|
|
|
|
|
except
|
|
|
|
|
that a hidden newline sequence is used, (which is removed
|
|
|
|
|
when inverting the file back to its original form with
|
|
|
|
|
.Xr unvis 1 ) .
|
|
|
|
|
If the last character in the encoded file does not end in a newline,
|
|
|
|
|
a hidden newline sequence is appended to the output.
|
|
|
|
|
This makes
|
|
|
|
|
the output usable with various editors and other utilities which
|
|
|
|
|
typically don't work with partial lines.
|
|
|
|
|
.It Fl f
|
|
|
|
|
Same as
|
|
|
|
|
.Fl F .
|
|
|
|
|
.It Fl l
|
|
|
|
|
Mark newlines with the visible sequence
|
|
|
|
|
.Ql \e$ ,
|
|
|
|
|
followed by the newline.
|
|
|
|
|
.It Fl n
|
|
|
|
|
Turns off any encoding, except for the fact that backslashes are
|
|
|
|
|
still doubled and hidden newline sequences inserted if
|
|
|
|
|
.Fl f
|
|
|
|
|
or
|
|
|
|
|
.Fl F
|
2004-07-02 22:22:35 +00:00
|
|
|
is selected.
|
|
|
|
|
When combined with the
|
1994-05-27 12:33:43 +00:00
|
|
|
.Fl f
|
|
|
|
|
flag,
|
1997-08-25 06:37:37 +00:00
|
|
|
.Nm
|
1994-05-27 12:33:43 +00:00
|
|
|
becomes like
|
|
|
|
|
an invertible version of the
|
|
|
|
|
.Xr fold 1
|
2004-07-02 22:22:35 +00:00
|
|
|
utility.
|
|
|
|
|
That is, the output
|
1994-05-27 12:33:43 +00:00
|
|
|
can be unfolded by running the output through
|
1996-07-25 18:11:30 +00:00
|
|
|
.Xr unvis 1 .
|
1994-05-27 12:33:43 +00:00
|
|
|
.It Fl o
|
|
|
|
|
Request a format which displays non-printable characters as
|
|
|
|
|
an octal number, \eddd.
|
|
|
|
|
.It Fl s
|
|
|
|
|
Only characters considered unsafe to send to a terminal are encoded.
|
|
|
|
|
This flag allows backspace, bell, and carriage return in addition
|
|
|
|
|
to the default space, tab and newline.
|
|
|
|
|
.It Fl t
|
|
|
|
|
Tabs are also encoded.
|
|
|
|
|
.It Fl w
|
|
|
|
|
White space (space-tab-newline) is also encoded.
|
|
|
|
|
.El
|
|
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr unvis 1 ,
|
|
|
|
|
.Xr vis 3
|
|
|
|
|
.Sh HISTORY
|
|
|
|
|
The
|
|
|
|
|
.Nm
|
1997-04-25 20:47:15 +00:00
|
|
|
command appeared in
|
1994-05-27 12:33:43 +00:00
|
|
|
.Bx 4.4 .
|
2004-06-24 16:08:02 +00:00
|
|
|
.Sh BUGS
|
|
|
|
|
Due to limitations in the underlying
|
|
|
|
|
.Xr vis 3
|
|
|
|
|
function, the
|
|
|
|
|
.Nm
|
|
|
|
|
utility
|
|
|
|
|
does not recognize multibyte characters, and thus may consider them to be
|
2004-07-02 22:25:40 +00:00
|
|
|
non-printable when they are in fact printable (and vice versa).
|
