Commit | Line | Data |
---|---|---|
c48bb276 C |
1 | .TH COL 1 "18 January 1983" |
2 | .SH NAME | |
3 | col \- filter reverse line feeds | |
4 | .SH SYNOPSIS | |
5 | .B col | |
6 | [ | |
7 | .B \-bfx | |
8 | ] | |
9 | .SH DESCRIPTION | |
10 | .I Col | |
11 | reads the standard input and writes the standard output. | |
12 | It performs the line overlays implied by reverse line | |
13 | feeds (ESC-7 in ASCII) | |
14 | and by forward and reverse half line feeds (ESC-9 and ESC-8). | |
15 | .I Col | |
16 | is particularly useful for filtering multicolumn | |
17 | output made with the `.rt' command of | |
18 | .I nroff | |
19 | and output resulting from use of the | |
20 | .IR tbl (1) | |
21 | preprocessor. | |
22 | .PP | |
23 | Although | |
24 | .I col | |
25 | accepts half line motions in its input, it normally does not | |
26 | emit them on output. | |
27 | Instead, text that would appear between lines is moved to the next lower | |
28 | full line boundary. | |
29 | This treatment can be suppressed by the | |
30 | .B \-f | |
31 | (fine) option; in this case | |
32 | the output from | |
33 | .I col | |
34 | may contain forward half line feeds (ESC-9), but will still never contain | |
35 | either kind of reverse line motion. | |
36 | .PP | |
37 | If the | |
38 | .B \-b | |
39 | option is given, | |
40 | .I col | |
41 | assumes that the output device in use is not capable of backspacing. | |
42 | In this case, if several characters are to appear in the same place, | |
43 | only the last one read will be taken. | |
44 | .PP | |
45 | The control characters SO (ASCII code 017), | |
46 | and SI (016) are assumed | |
47 | to start and end text in an alternate character set. | |
48 | The character set (primary or alternate) associated with each printing | |
49 | character read is remembered; on output, SO and SI characters are generated | |
50 | where necessary to maintain the correct treatment of each character. | |
51 | .PP | |
52 | .I Col | |
53 | normally converts white space to tabs to shorten printing time. | |
54 | If the | |
55 | .B \-x | |
56 | option is given, this conversion is suppressed. | |
57 | .PP | |
58 | All control characters are removed from the input except space, | |
59 | backspace, | |
60 | tab, return, newline, ESC (033) followed by one of 7, 8, 9, SI, SO, and VT | |
61 | (013). | |
62 | This last character is an alternate form of full reverse line feed, for | |
63 | compatibility with some other hardware conventions. | |
64 | All other non-printing characters are ignored. | |
65 | .SH "SEE ALSO" | |
66 | troff(1), tbl(1) | |
67 | .SH BUGS | |
68 | Can't back up more than 128 lines. | |
69 | .br | |
70 | No more than 800 characters, including backspaces, on a line. |