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28 .\" @(#)colcrt.1 8.1 (Berkeley) 6/30/93
29 .\" $FreeBSD: head/usr.bin/colcrt/colcrt.1 216370 2010-12-11 08:32:16Z joel $
36 .Nd filter nroff output for CRT previewing
45 utility provides virtual half-line and reverse line feed sequences
46 for terminals without such capability, and on which overstriking
48 Half-line characters and underlining (changed to dashing `\-')
49 are placed on new lines in between the normal output lines.
51 The following options are available:
52 .Bl -tag -width indent
54 Suppress all underlining.
55 This option is especially useful for previewing
60 Cause all half-lines to be printed, effectively double spacing the output.
61 Normally, a minimal space output format is used which will suppress empty
63 The program never suppresses two consecutive empty lines, however.
66 option is useful for sending output to the line printer when the output
67 contains superscripts and subscripts which would otherwise be invisible.
74 environment variables affect the execution of
85 tbl exum2.n \&| nroff \-ms \&| colcrt \- \&| more
99 Should fold underlines onto blanks even with the
102 a true underline character would show.
104 Cannot back up more than 102 lines.
106 General overstriking is lost;
114 Lines are trimmed to 132 characters.
116 Some provision should be made for processing superscripts and subscripts
117 in documents which are already double-spaced.
119 Characters that take up more than one column position may not be
120 underlined correctly.