1COLCRT(1) General Commands Manual COLCRT(1)
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6 colcrt - filter nroff output for CRT previewing
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9 colcrt [ - ] [ -2 ] [ file ... ]
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12 Colcrt provides virtual half-line and reverse line feed sequences for
13 terminals without such capability, and on which overstriking is
14 destructive. Half-line characters and underlining (changed to dashing
15 `-') are placed on new lines in between the normal output lines.
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17 The optional - suppresses all underlining. It is especially useful for
18 previewing allboxed tables from tbl(1).
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20 The option -2 causes all half-lines to be printed, effectively double
21 spacing the output. Normally, a minimal space output format is used
22 which will suppress empty lines. The program never suppresses two con‐
23 secutive empty lines, however. The -2 option is useful for sending
24 output to the line printer when the output contains superscripts and
25 subscripts which would otherwise be invisible.
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27 A typical use of colcrt would be
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29 tbl exum2.n | nroff -ms | colcrt - | more
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32 nroff/troff(1), col(1), more(1), ul(1)
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35 Should fold underlines onto blanks even with the `-' option so that a
36 true underline character would show; if we did this, however, colcrt
37 wouldn't get rid of cu'd underlining completely.
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39 Can't back up more than 102 lines.
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41 General overstriking is lost; as a special case `|' overstruck with `-'
42 or underline becomes `+'.
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44 Lines are trimmed to 132 characters.
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46 Some provision should be made for processing superscripts and sub‐
47 scripts in documents which are already double-spaced.
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513rd Berkeley Distribution May 7, 1986 COLCRT(1)