1.\" Copyright (c) 1989, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)vis.1 5.2 (Berkeley) 4/23/91 33.\" $Id: vis.1,v 1.2 1993/08/01 07:27:06 mycroft Exp $ 34.\" 35.Dd April 23, 1991 36.Dt VIS 1 37.Os 38.Sh NAME 39.Nm vis 40.Nd display non-printable characters in a visual format 41.Sh SYNOPSIS 42.Nm vis 43.Op Fl cbflnostw 44.Op Fl F Ar foldwidth 45.Op Ar file ... 46.Sh DESCRIPTION 47.Nm Vis 48is a filter for converting non-printable characters 49into a visual representation. It differs from 50.Ql cat -v 51in that 52the form is unique and invertible. By default, all non-graphic 53characters except space, tab, and newline are encoded. 54A detailed description of the 55various visual formats is given in 56.Xr vis 3 . 57.Pp 58Options supported by 59.Nm vis : 60.Bl -tag -width Ds 61.It Fl b 62Turns off prepending of backslash before up-arrow control sequences 63and meta characters, and disables the doubling of backslashes. This 64produces output which is neither invertible or precise, but does 65represent a minimum of change to the input. It is similar to 66.Dq Li cat -v . 67.It Fl c 68Request a format which displays a small subset of the 69non-printable characters using C-style backslash sequences. 70.It Fl F 71Causes 72.Nm vis 73to fold output lines to foldwidth columns (default 80), like 74.Xr fold 1 , 75except 76that a hidden newline sequence is used, (which is removed 77when inverting the file back to its original form with 78.Xr unvis 1 ) . 79If the last character in the encoded file does not end in a newline, 80a hidden newline sequence is appended to the output. 81This makes 82the output usuable with various editors and other utilities which 83typically don't work with partial lines. 84.It Fl f 85Same as 86.Fl F . 87.It Fl l 88Mark newlines with the visable sequence 89.Ql \e$ , 90followed by the newline. 91.It Fl n 92Turns off any encoding, except for the fact that backslashes are 93still doubled and hidden newline sequences inserted if 94.Fl f 95or 96.Fl F 97is selected. When combined with the 98.Fl f 99flag, 100.Nm vis 101becomes like 102an invertible version of the 103.Xr fold 1 104utility. That is, the output 105can be unfolded by running the output through 106.It Fl o 107Request a format which displays non-printable characters as 108an octal number, \eddd. 109.It Fl s 110Only characters considered unsafe to send to a terminal are encoded. 111This flag allows backspace, bell, and carriage return in addition 112to the default space, tab and newline. 113.Xr unvis 1 . 114.It Fl t 115Tabs are also encoded. 116.It Fl w 117White space (space-tab-newline) is also encoded. 118.El 119.Sh SEE ALSO 120.Xr unvis 1 121.Xr vis 3 122.Sh HISTORY 123The 124.Nm 125command is 126.Ud . 127