1.\" Copyright (c) 1980, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)colcrt.1 6.6 (Berkeley) 07/24/90 7.\" 8.Dd 9.Dt COLCRT 1 10.OS BSD 3 11.Sh NAME 12.Nm colcrt 13.Nd filter nroff output for CRT previewing 14.Sh SYNOPSIS 15.Nm colcrt 16.Op Fl 17.Op Fl \&2 18.Ar 19.Sh DESCRIPTION 20.Nm Colcrt 21provides virtual half-line and reverse line feed sequences 22for terminals without such capability, and on which overstriking 23is destructive. 24Half-line characters and underlining (changed to dashing `\-') 25are placed on new lines in between the normal output lines. 26.Pp 27.Tw Ds 28.Tp Fl 29Suppress all underlining. 30It is especially useful for previewing 31.Ar allboxed 32tables from 33.Xr tbl 1 . 34.Pp 35.Tp Fl 2 36Causes all half-lines to be printed, effectively double spacing the output. 37Normally, a minimal space output format is used which will suppress empty 38lines. 39The program never suppresses two consecutive empty lines, however. 40The 41.Fl 2 42option is useful for sending output to the line printer when the output 43contains superscripts and subscripts which would otherwise be invisible. 44.Tp 45.Pp 46A typical use of 47.Nm colcrt 48would be 49.Pp 50.Dl tbl exum2.n \&| nroff \-ms \&| colcrt \- \&| more 51.Sh SEE ALSO 52.Xr nroff 1 , 53.Xr troff 1 , 54.Xr col 1 , 55.Xr more 1 , 56.Xr ul 1 57.Sh HISTORY 58Appeared in 3 BSD. 59.Sh BUGS 60Should fold underlines onto blanks even with the 61.Sq Fl 62option so that 63a true underline character would show; if we did this, however, 64.Nm colcrt 65wouldn't get rid of 66.Ar cu'd 67underlining 68completely. 69.Pp 70Can't back up more than 102 lines. 71.Pp 72General overstriking is lost; 73as a special case `\&|' overstruck with `\-' or underline becomes `+'. 74.Pp 75Lines are trimmed to 132 characters. 76.Pp 77Some provision should be made for processing superscripts and subscripts 78in documents which are already double-spaced. 79