4.4BSD/usr/share/man/cat1/vis.0

VIS(1)                       BSD Reference Manual                       VIS(1)

NNAAMMEE
     vviiss - display non-printable characters in a visual format

SSYYNNOOPPSSIISS
     vviiss [--ccbbffllnnoossttww] [--FF _f_o_l_d_w_i_d_t_h] [_f_i_l_e _._._.]

DDEESSCCRRIIPPTTIIOONN
     VViiss 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).

     Options supported by vviiss:

     --bb      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 or
             precise, but does represent a minimum of change to the input.  It
             is similar to ``cat -v''.

     --cc      Request a format which displays a small subset of the non-
             printable characters using C-style backslash sequences.

     --FF      Causes vviiss 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 orig-
             inal form with unvis(1)).  If the last character in the encoded
             file does not end in a newline, a hidden newline sequence is ap-
             pended to the output.  This makes the output usuable with various
             editors and other utilities which typically don't work with par-
             tial lines.

     --ff      Same as --FF.

     --ll      Mark newlines with the visable sequence `\$', followed by the
             newline.

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

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

     --ss      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.  unvis(1).

     --tt      Tabs are also encoded.

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

SSEEEE AALLSSOO
     unvis(1) vis(3)

HHIISSTTOORRYY
     The vviiss command appears in 4.4BSD.

4.4BSD                           June 6, 1993                                1