linux/scripts/cleanfile
<<
>>
Prefs
   1#!/usr/bin/perl -w
   2#
   3# Clean a text file -- or directory of text files -- of stealth whitespace.
   4# WARNING: this can be a highly destructive operation.  Use with caution.
   5#
   6
   7use bytes;
   8use File::Basename;
   9
  10# Default options
  11$max_width = 79;
  12
  13# Clean up space-tab sequences, either by removing spaces or
  14# replacing them with tabs.
  15sub clean_space_tabs($)
  16{
  17    no bytes;                   # Tab alignment depends on characters
  18
  19    my($li) = @_;
  20    my($lo) = '';
  21    my $pos = 0;
  22    my $nsp = 0;
  23    my($i, $c);
  24
  25    for ($i = 0; $i < length($li); $i++) {
  26        $c = substr($li, $i, 1);
  27        if ($c eq "\t") {
  28            my $npos = ($pos+$nsp+8) & ~7;
  29            my $ntab = ($npos >> 3) - ($pos >> 3);
  30            $lo .= "\t" x $ntab;
  31            $pos = $npos;
  32            $nsp = 0;
  33        } elsif ($c eq "\n" || $c eq "\r") {
  34            $lo .= " " x $nsp;
  35            $pos += $nsp;
  36            $nsp = 0;
  37            $lo .= $c;
  38            $pos = 0;
  39        } elsif ($c eq " ") {
  40            $nsp++;
  41        } else {
  42            $lo .= " " x $nsp;
  43            $pos += $nsp;
  44            $nsp = 0;
  45            $lo .= $c;
  46            $pos++;
  47        }
  48    }
  49    $lo .= " " x $nsp;
  50    return $lo;
  51}
  52
  53# Compute the visual width of a string
  54sub strwidth($) {
  55    no bytes;                   # Tab alignment depends on characters
  56
  57    my($li) = @_;
  58    my($c, $i);
  59    my $pos = 0;
  60    my $mlen = 0;
  61
  62    for ($i = 0; $i < length($li); $i++) {
  63        $c = substr($li,$i,1);
  64        if ($c eq "\t") {
  65            $pos = ($pos+8) & ~7;
  66        } elsif ($c eq "\n") {
  67            $mlen = $pos if ($pos > $mlen);
  68            $pos = 0;
  69        } else {
  70            $pos++;
  71        }
  72    }
  73
  74    $mlen = $pos if ($pos > $mlen);
  75    return $mlen;
  76}
  77
  78$name = basename($0);
  79
  80@files = ();
  81
  82while (defined($a = shift(@ARGV))) {
  83    if ($a =~ /^-/) {
  84        if ($a eq '-width' || $a eq '-w') {
  85            $max_width = shift(@ARGV)+0;
  86        } else {
  87            print STDERR "Usage: $name [-width #] files...\n";
  88            exit 1;
  89        }
  90    } else {
  91        push(@files, $a);
  92    }
  93}
  94
  95foreach $f ( @files ) {
  96    print STDERR "$name: $f\n";
  97
  98    if (! -f $f) {
  99        print STDERR "$f: not a file\n";
 100        next;
 101    }
 102
 103    if (!open(FILE, '+<', $f)) {
 104        print STDERR "$name: Cannot open file: $f: $!\n";
 105        next;
 106    }
 107
 108    binmode FILE;
 109
 110    # First, verify that it is not a binary file; consider any file
 111    # with a zero byte to be a binary file.  Is there any better, or
 112    # additional, heuristic that should be applied?
 113    $is_binary = 0;
 114
 115    while (read(FILE, $data, 65536) > 0) {
 116        if ($data =~ /\0/) {
 117            $is_binary = 1;
 118            last;
 119        }
 120    }
 121
 122    if ($is_binary) {
 123        print STDERR "$name: $f: binary file\n";
 124        next;
 125    }
 126
 127    seek(FILE, 0, 0);
 128
 129    $in_bytes = 0;
 130    $out_bytes = 0;
 131    $blank_bytes = 0;
 132
 133    @blanks = ();
 134    @lines  = ();
 135    $lineno = 0;
 136
 137    while ( defined($line = <FILE>) ) {
 138        $lineno++;
 139        $in_bytes += length($line);
 140        $line =~ s/[ \t\r]*$//;         # Remove trailing spaces
 141        $line = clean_space_tabs($line);
 142
 143        if ( $line eq "\n" ) {
 144            push(@blanks, $line);
 145            $blank_bytes += length($line);
 146        } else {
 147            push(@lines, @blanks);
 148            $out_bytes += $blank_bytes;
 149            push(@lines, $line);
 150            $out_bytes += length($line);
 151            @blanks = ();
 152            $blank_bytes = 0;
 153        }
 154
 155        $l_width = strwidth($line);
 156        if ($max_width && $l_width > $max_width) {
 157            print STDERR
 158                "$f:$lineno: line exceeds $max_width characters ($l_width)\n";
 159        }
 160    }
 161
 162    # Any blanks at the end of the file are discarded
 163
 164    if ($in_bytes != $out_bytes) {
 165        # Only write to the file if changed
 166        seek(FILE, 0, 0);
 167        print FILE @lines;
 168
 169        if ( !defined($where = tell(FILE)) ||
 170             !truncate(FILE, $where) ) {
 171            die "$name: Failed to truncate modified file: $f: $!\n";
 172        }
 173    }
 174
 175    close(FILE);
 176}
 177
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.