NAME¶
col —
filter reverse line feeds from input
SYNOPSIS¶
DESCRIPTION¶
The 
col utility filters out reverse (and half
  reverse) line feeds so that the output is in the correct order with only
  forward and half forward line feeds, and replaces white-space characters with
  tabs where possible. This can be useful in processing the output of
  
nroff(1) and 
tbl(1).
The 
col utility reads from the standard input
  and writes to the standard output.
The options are as follows:
  -b 
  - Do not output any backspaces, printing only the last character written to
      each column position.
 
  -f 
  - Forward half line feeds are permitted (``fine'' mode). Normally characters
      printed on a half line boundary are printed on the following line.
 
  -h 
  - Do not output multiple spaces instead of tabs (default).
 
  -l
    num 
  - Buffer at least num lines in memory. By
      default, 128 lines are buffered.
 
  -p 
  - Force unknown control sequences to be passed through unchanged. Normally,
      
col will filter out any control
      sequences from the input other than those recognized and interpreted by
      itself, which are listed below. 
  -x 
  - Output multiple spaces instead of tabs.
 
The control sequences for carriage motion that
  
col understands and their decimal values
  are listed in the following table:
  - ESC-7
 
  - reverse line feed (escape then 7)
 
  - ESC-8
 
  - half reverse line feed (escape then 8)
 
  - ESC-9
 
  - half forward line feed (escape then 9)
 
  - backspace
 
  - moves back one column (8); ignored in the first column
 
  - carriage return
 
  - (13)
 
  - newline
 
  - forward line feed (10); also does carriage return
 
  - shift in
 
  - shift to normal character set (15)
 
  - shift out
 
  - shift to alternate character set (14)
 
  - space
 
  - moves forward one column (32)
 
  - tab
 
  - moves forward to next tab stop (9)
 
  - vertical tab
 
  - reverse line feed (11)
 
All unrecognized control characters and escape sequences are discarded.
The 
col utility keeps track of the character
  set as characters are read and makes sure the character set is correct when
  they are output.
If the input attempts to back up to the last flushed line,
  
col will display a warning message.
ENVIRONMENT¶
The 
LANG,
  
LC_ALL and
  
LC_CTYPE environment variables affect the
  execution of 
col as described in
  
environ(7).
EXIT STATUS¶
The 
col utility exits 0 on success,
  and >0 if an error occurs.
SEE ALSO¶
colcrt(1), 
expand(1),
  
nroff(1), 
tbl(1)
STANDARDS¶
The 
col utility conforms to
  
Version 2 of the Single UNIX Specification
  (“SUSv2”).
HISTORY¶
A 
col command appeared in
  
Version 6 AT&T UNIX.