#!/usr/bin/env perl # # Clean a text file -- or directory of text files -- of stealth whitespace. # WARNING: this can be a highly destructive operation. Use with caution. # use bytes; use File::Basename; use warnings; # Default options $max_width = 79; # Clean up space-tab sequences, either by removing spaces or # replacing them with tabs. sub clean_space_tabs($) { no bytes; # Tab alignment depends on characters my($li) = @_; my($lo) = ''; my $pos = 0; my $nsp = 0; my($i, $c); for ($i = 0; $i < length($li); $i++) { $c = substr($li, $i, 1); if ($c eq "\t") { my $npos = ($pos+$nsp+8) & ~7; my $ntab = ($npos >> 3) - ($pos >> 3); $lo .= "\t" x $ntab; $pos = $npos; $nsp = 0; } elsif ($c eq "\n" || $c eq "\r") { $lo .= " " x $nsp; $pos += $nsp; $nsp = 0; $lo .= $c; $pos = 0; } elsif ($c eq " ") { $nsp++; } else { $lo .= " " x $nsp; $pos += $nsp; $nsp = 0; $lo .= $c; $pos++; } } $lo .= " " x $nsp; return $lo; } # Compute the visual width of a string sub strwidth($) { no bytes; # Tab alignment depends on characters my($li) = @_; my($c, $i); my $pos = 0; my $mlen = 0; for ($i = 0; $i < length($li); $i++) { $c = substr($li,$i,1); if ($c eq "\t") { $pos = ($pos+8) & ~7; } elsif ($c eq "\n") { $mlen = $pos if ($pos > $mlen); $pos = 0; } else { $pos++; } } $mlen = $pos if ($pos > $mlen); return $mlen; } $name = basename($0); @files = (); while (defined($a = shift(@ARGV))) { if ($a =~ /^-/) { if ($a eq '-width' || $a eq '-w') { $max_width = shift(@ARGV)+0; } else { print STDERR "Usage: $name [-width #] files...\n"; exit 1; } } else { push(@files, $a); } } foreach $f ( @files ) { print STDERR "$name: $f\n"; if (! -f $f) { print STDERR "$f: not a file\n"; next; } if (!open(FILE, '+<', $f)) { print STDERR "$name: Cannot open file: $f: $!\n"; next; } binmode FILE; # First, verify that it is not a binary file; consider any file # with a zero byte to be a binary file. Is there any better, or # additional, heuristic that should be applied? $is_binary = 0; while (read(FILE, $data, 65536) > 0) { if ($data =~ /\0/) { $is_binary = 1; last; } } if ($is_binary) { print STDERR "$name: $f: binary file\n"; next; } seek(FILE, 0, 0); $in_bytes = 0; $out_bytes = 0; $blank_bytes = 0; @blanks = (); @lines = (); $lineno = 0; while ( defined($line = <FILE>) ) { $lineno++; $in_bytes += length($line); $line =~ s/[ \t\r]*$//; # Remove trailing spaces $line = clean_space_tabs($line); if ( $line eq "\n" ) { push(@blanks, $line); $blank_bytes += length($line); } else { push(@lines, @blanks); $out_bytes += $blank_bytes; push(@lines, $line); $out_bytes += length($line); @blanks = (); $blank_bytes = 0; } $l_width = strwidth($line); if ($max_width && $l_width > $max_width) { print STDERR "$f:$lineno: line exceeds $max_width characters ($l_width)\n"; } } # Any blanks at the end of the file are discarded if ($in_bytes != $out_bytes) { # Only write to the file if changed seek(FILE, 0, 0); print FILE @lines; if ( !defined($where = tell(FILE)) || !truncate(FILE, $where) ) { die "$name: Failed to truncate modified file: $f: $!\n"; } } close(FILE); }