VIS(1)                     OpenBSD Reference Manual                     VIS(1)

NAME
     vis - display non-printable characters in a visual format

SYNOPSIS
     vis [-cbflnostw] [-F foldwidth] [file ...]

DESCRIPTION
     vis is a filter for converting non-printable characters into a visual
     representation.  It differs from cat -v in that 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 vis(3).

     The options are as follows:

     -b      Turns off prepending of backslash before up-arrow control se-
             quences and meta-characters, and disables the doubling of back-
             slashes.  This produces output which is neither invertible nor
             precise, but does represent a minimum of change to the input.  It
             is similar to cat -v.

     -c      Request a format which displays a small subset of the non-print-
             able characters using C-style backslash sequences.

     -F      Causes vis to fold output lines to foldwidth columns (default
             80), like fold(1), except that a hidden newline sequence is used,
             (which is removed when inverting the file back to its original
             form with 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.

     -f      Same as -F.

     -l      Mark newlines with the visible sequence `\$', followed by the
             newline.

     -n      Turns off any encoding, except for the fact that backslashes are
             still doubled and hidden newline sequences inserted if -f or -F
             is selected.  When combined with the -f flag, vis becomes like an
             invertible version of the fold(1) utility.  That is, the output
             can be unfolded by running the output through unvis(1).

     -o      Request a format which displays non-printable characters as an
             octal number, \ddd.

     -s      Only characters considered unsafe to send to a terminal are en-
             coded.  This flag allows backspace, bell, and carriage return in
             addition to the default space, tab and newline.

     -t      Tabs are also encoded.

     -w      White space (space-tab-newline) is also encoded.

SEE ALSO
     unvis(1), vis(3)

HISTORY
     The vis command appeared in 4.4BSD.

OpenBSD 2.9                     April 19, 1994                               1
