Commit | Line | Data |
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12b31560 PA |
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 | ||
7 | use bytes; | |
8 | use File::Basename; | |
9 | ||
cb3ed5b7 PA |
10 | # Default options |
11 | $max_width = 79; | |
12 | ||
12b31560 PA |
13 | # Clean up space-tab sequences, either by removing spaces or |
14 | # replacing them with tabs. | |
15 | sub clean_space_tabs($) | |
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 $lo; | |
51 | } | |
52 | ||
cb3ed5b7 PA |
53 | # Compute the visual width of a string |
54 | sub strwidth($) { | |
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 | ||
12b31560 PA |
78 | $name = basename($0); |
79 | ||
cb3ed5b7 PA |
80 | @files = (); |
81 | ||
82 | while (defined($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 | ||
95 | foreach $f ( @files ) { | |
12b31560 PA |
96 | print STDERR "$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 = (); | |
cb3ed5b7 | 135 | $lineno = 0; |
12b31560 PA |
136 | |
137 | while ( defined($line = <FILE>) ) { | |
cb3ed5b7 | 138 | $lineno++; |
12b31560 PA |
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 | } | |
cb3ed5b7 PA |
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 | } | |
12b31560 PA |
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 | } |