COLCRT(1) | General Commands Manual | COLCRT(1)

# NAME

`colcrt` —
filter nroff output for CRT previewing

# SYNOPSIS

`colcrt` | [`-`] [`-2`] [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.

Available options:

`-`
  Suppress all underlining. This option is especially useful for previewing allboxed tables from tbl(1).
`-2`
  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.

# 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)

# HISTORY

The `colcrt` command appeared in 1BSD.

# 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.

June 30, 1993 | NetBSD 9.5