colcrt(1) filter nroff output for CRT previewing

SYNOPSIS

[- ] [-2 ] [file ... ]

DESCRIPTION

The utility provides virtual half-line and reverse line feed sequences for terminals without such capability, and on which overstriking is destructive. Half-line characters and underlining (changed to dashing `-') are placed on new lines in between the normal output lines.

The following options are available:

-
Suppress all underlining. This option is especially useful for previewing allboxed tables from tbl(1).
-2
Cause all half-lines to be printed, effectively double spacing the output. Normally, a minimal space output format is used which will suppress empty lines. The program never suppresses two consecutive empty lines, however. The -2 option is useful for sending output to the line printer when the output contains superscripts and subscripts which would otherwise be invisible.

ENVIRONMENT

The LANG , LC_ALL and LC_CTYPE environment variables affect the execution of as described in environ(7).

EXIT STATUS

Ex -std

EXAMPLES

A typical use of would be
tbl exum2.n | nroff -ms | colcrt - | more

HISTORY

The command appeared in BSD 3.0

BUGS

Should fold underlines onto blanks even with the `- ' option so that a true underline character would show.

Cannot back up more than 102 lines.

General overstriking is lost; as a special case `|' overstruck with `-' or underline becomes `+'

Lines are trimmed to 132 characters.

Some provision should be made for processing superscripts and subscripts in documents which are already double-spaced.

Characters that take up more than one column position may not be underlined correctly.