colcrt − 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 partially invisible.
−h, −−help
Display help text and exit.
−V, −−version
Print version and exit.
The colcrt command appeared in 3.0BSD.
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.
A typical use of colcrt would be:
tbl exum2.n | nroff −ms | colcrt − | more
col(1), more(1), nroff(1), troff(1), ul(1)
For bug reports, use the issue tracker at <https://github.com/util−linux/util−linux/issues>.
The colcrt command is part of the util−linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util−linux/>.