COLCRT(1)

NAME
colcrt - filter nroff output for CRT previewing

SYNOPSIS

colcrt [options] [file ...]

DESCRIPTION

colcrt 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.

OPTIONS

-, --no-underlining
    Suppress all underlining. This option is especially useful for previewing allboxed tables from tbl(1).

-2, --half-lines
    Causes 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.

-V, --version
    Display version information and exit.

-h, --help
    Display help text and exit.

HISTORY

The colcrt command appeared in 3.0BSD.

BUGS

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

Can’t 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.

EXAMPLES

A typical use of colcrt would be:

    tbl exum2.n | nroff -ms | colcrt - | more

SEE ALSO

col(1), more(1), nroff(1), troff(1), ul(1)

REPORTING BUGS

For bug reports, use the issue tracker at

AVAILABILITY

The colcrt command is part of the util-linux package which can be downloaded from