Tristan Matthews | 0461646 | 2013-11-14 16:09:34 -0500 | [diff] [blame] | 1 | #! /usr/bin/perl -w |
| 2 | |
| 3 | # Script to take the output of nroff -man and remove all the backspacing and |
| 4 | # the page footers and the screen commands etc so that it is more usefully |
| 5 | # readable online. In fact, in the latest nroff, intermediate footers don't |
| 6 | # seem to be generated any more. |
| 7 | |
| 8 | $blankcount = 0; |
| 9 | $lastwascut = 0; |
| 10 | $firstheader = 1; |
| 11 | |
| 12 | # Input on STDIN; output to STDOUT. |
| 13 | |
| 14 | while (<STDIN>) |
| 15 | { |
| 16 | s/\x1b\[\d+m//g; # Remove screen controls "ESC [ number m" |
| 17 | s/.\x8//g; # Remove "char, backspace" |
| 18 | |
| 19 | # Handle header lines. Retain only the first one we encounter, but remove |
| 20 | # the blank line that follows. Any others (e.g. at end of document) and the |
| 21 | # following blank line are dropped. |
| 22 | |
| 23 | if (/^PCRE(\w*)\(([13])\)\s+PCRE\1\(\2\)$/) |
| 24 | { |
| 25 | if ($firstheader) |
| 26 | { |
| 27 | $firstheader = 0; |
| 28 | print; |
| 29 | $lastprinted = $_; |
| 30 | $lastwascut = 0; |
| 31 | } |
| 32 | $_=<STDIN>; # Remove a blank that follows |
| 33 | next; |
| 34 | } |
| 35 | |
| 36 | # Count runs of empty lines |
| 37 | |
| 38 | if (/^\s*$/) |
| 39 | { |
| 40 | $blankcount++; |
| 41 | $lastwascut = 0; |
| 42 | next; |
| 43 | } |
| 44 | |
| 45 | # If a chunk of lines has been cut out (page footer) and the next line |
| 46 | # has a different indentation, put back one blank line. |
| 47 | |
| 48 | if ($lastwascut && $blankcount < 1 && defined($lastprinted)) |
| 49 | { |
| 50 | ($a) = $lastprinted =~ /^(\s*)/; |
| 51 | ($b) = $_ =~ /^(\s*)/; |
| 52 | $blankcount++ if ($a ne $b); |
| 53 | } |
| 54 | |
| 55 | # We get here only when we have a non-blank line in hand. If it was preceded |
| 56 | # by 3 or more blank lines, read the next 3 lines and see if they are blank. |
| 57 | # If so, remove all 7 lines, and remember that we have just done a cut. |
| 58 | |
| 59 | if ($blankcount >= 3) |
| 60 | { |
| 61 | for ($i = 0; $i < 3; $i++) |
| 62 | { |
| 63 | $next[$i] = <STDIN>; |
| 64 | $next[$i] = "" if !defined $next[$i]; |
| 65 | $next[$i] =~ s/\x1b\[\d+m//g; # Remove screen controls "ESC [ number m" |
| 66 | $next[$i] =~ s/.\x8//g; # Remove "char, backspace" |
| 67 | } |
| 68 | |
| 69 | # Cut out chunks of the form <3 blanks><non-blank><3 blanks> |
| 70 | |
| 71 | if ($next[0] =~ /^\s*$/ && |
| 72 | $next[1] =~ /^\s*$/ && |
| 73 | $next[2] =~ /^\s*$/) |
| 74 | { |
| 75 | $blankcount -= 3; |
| 76 | $lastwascut = 1; |
| 77 | } |
| 78 | |
| 79 | # Otherwise output the saved blanks, the current, and the next three |
| 80 | # lines. Remember the last printed line. |
| 81 | |
| 82 | else |
| 83 | { |
| 84 | for ($i = 0; $i < $blankcount; $i++) { print "\n"; } |
| 85 | print; |
| 86 | for ($i = 0; $i < 3; $i++) |
| 87 | { |
| 88 | $next[$i] =~ s/.\x8//g; |
| 89 | print $next[$i]; |
| 90 | $lastprinted = $_; |
| 91 | } |
| 92 | $lastwascut = 0; |
| 93 | $blankcount = 0; |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | # This non-blank line is not preceded by 3 or more blank lines. Output |
| 98 | # any blanks there are, and the line. Remember it. Force two blank lines |
| 99 | # before headings. |
| 100 | |
| 101 | else |
| 102 | { |
| 103 | $blankcount = 2 if /^\S/ && !/^Last updated/ && !/^Copyright/ && |
| 104 | defined($lastprinted); |
| 105 | for ($i = 0; $i < $blankcount; $i++) { print "\n"; } |
| 106 | print; |
| 107 | $lastprinted = $_; |
| 108 | $lastwascut = 0; |
| 109 | $blankcount = 0; |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | # End |