release/src/router/pcre/CleanTxt

   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