filter nroff output for CRT previewing


colcrt [options] [file...]


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.


- , --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.


A typical use of colcrt would be:

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


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.


The colcrt command appeared in 3.0BSD.


The colcrt command is part of the util-linux package and is available from https:// /pub /linux /utils /util-linux/ Linux Kernel Archive .


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

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