

col                          Command                          col




Remove reverse and half-line motions

ccooll [ -bbddffxx ][ -pp_n ]

The command col reads the  standard input and writes to the stan-
dard output.   It removes reverse and  half-line motions from the
output of  nroff for  the benefit  of output devices  that cannot
perform them.   It maintains an  image of the page  in memory and
performs these  motions virtually  so they  do not appear  on the
output.

col understands  four escape sequences: <esc>  7 for reverse line
feed, <esc> 8  for half reverse line feed, <esc>  9 for half for-
ward line feed, and <esc> B  for a forward line feed.  It removes
<esc> (ASCII 033) from the input  stream if it is followed by any
other character.

Eight control  characters besides  <esc> are interpreted  by col.
Newline,  return, space,  backspace,  and tab  carry their  usual
meaning.  VT  (013) is  an alternate  form of reverse  line feed.
The characters SO (017) and SI  (016) signal the start and end of
text in an  alternate character set.  col remembers the character
set for each character and uses  SO and SI to distinguish them on
the output.   col removes all  other control characters  from the
input stream.

ccooll recognizes the following options:

-bb  The  output device cannot backspace.  Only the  last of a set
    of characters destined for a given position will appear.

-dd  Double-space the output.   This doubles the length of a docu-
    ment but preserves  relative vertical spacing.  The -f option
    has precedence.

-ff  The output  device can perform half-forward line feeds.  Full
    lines  appear single  spaced  with half  lines between  them.
    This is  the only situation in which  half forward line feeds
    appear in the output of col -- reverse line motions never ap-
    pear.

-xx  Suppress  the default  conversion of  white space to  tabs on
    output.

-pp _n
    Set the  internal page buffer size to  n full lines (default,
    128).

If neither -f nor -d is chosen, col moves non-empty half lines to
the  next lower  full line  and pushes all  later lines  down one
line.  This can distort the appearance of the document.





COHERENT Lexicon                                           Page 1




col                          Command                          col



***** See Also *****

ASCII, commands, nroff

***** Notes *****

Backing up  past the start  of a document  or of the  page buffer
loses characters.

















































COHERENT Lexicon                                           Page 2


