.\" Copyright (c) 1989, 1991 The Regents of the University of California.
.\" %sccs.include.redist.roff%
.\" @(#)vis.1 5.2 (Berkeley) %G%
.Nd display non-printable characters in a visual format
is a filter for converting non-printable characters
into a visual representation. It differs from
the form is unique and invertible. By default, all non-graphic
characters except space, tab, and newline are encoded.
A detailed description of the
various visual formats is given in
Turns off prepending of backslash before up-arrow control sequences
and meta characters, and disables the doubling of backslashes. This
produces output which is neither invertible or precise, but does
represent a minimum of change to the input. It is similar to
Request a format which displays a small subset of the
non-printable characters using C-style backslash sequences.
to fold output lines to foldwidth columns (default 80), like
that a hidden newline sequence is used, (which is removed
when inverting the file back to its original form with
If the last character in the encoded file does not end in a newline,
a hidden newline sequence is appended to the output.
the output usuable with various editors and other utilities which
typically don't work with partial lines.
Mark newlines with the visable sequence
Turns off any encoding, except for the fact that backslashes are
still doubled and hidden newline sequences inserted if
is selected. When combined with the
an invertible version of the
utility. That is, the output
can be unfolded by running the output through
Request a format which displays non-printable characters as
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.
White space (space-tab-newline) is also encoded.