Commands Reference, Volume 1

colcrt Command

Purpose

Filters nroff command output for cathode ray tube (CRT) previewing.

The colcrt command filters output from the nroff command so that the output can be previewed on a CRT. The colcrt command provides virtual half-line-feed and reverse line-feed sequences for terminals without these capabilities. The colcrt command changes underline characters to dashes and places these characters and the half-line characters on new lines between the normal output lines.

Notes:

Use this command with the 37 viewing device
The - (minus sign) flag removes all underlining; therefore, a true underline character does not show with the - (minus sign) flag.
It is not possible to back up more than 102 lines.
General overstriking is lost. As a special case, the | (vertical bar) overstruck with the - (dash) or the _ (underline) characters becomes the + (plus sign).
Lines are truncated to up to 132 characters.

Parameters

File

Specifies a file processed by the nroff command for viewing on a CRT.

Flags

-	Suppresses underlining. This flag is useful for previewing boxed tables from the tbl command.
-2	Causes all half-lines to be printed, effectively double-spacing the output. This is useful when printing output with subscripts and superscripts on a line printer, where half-lines normally are not displayed.

Examples

A typical use of the colcrt command is:

tbl exum2.n | nroff -ms -T37 | colcrt - | pg

Related Information

The col command, nroff command, pg command, tbl command, troff command, ul command.