MirBSD manpage: vis(1)

VIS(1)                       BSD Reference Manual                       VIS(1)


     vis - display non-printable characters in a visual format


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


     vis is a filter for converting non-printable characters into a visual
     representation. It differs from cat -v in that the form can be unique and
     invertible. By default, all non-printing characters except space, tab,
     and newline are encoded, as are any meta-characters (eighth bit set). 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
             backslashes. 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-
             printable characters using C-style backslash sequences.

     -F foldwidth
             Causes vis to fold output lines to foldwidth columns, 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 out-
             put. This makes the output usable with various editors and other
             utilities which typically don't work with partial lines.

     -f      Like -F, except output is always folded to 80 columns.

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

     -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. Meta-characters
             that are considered graphic characters by isgraph(3) are not en-

     -t      Tabs are also encoded.

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


     unvis(1), vis(3)


     The vis command appeared in 4.4BSD.

MirBSD #10-current              April 19, 1994                               1

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