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cb77f0d6 | 1 | #!/usr/bin/env perl |
b2441318 | 2 | # SPDX-License-Identifier: GPL-2.0 |
12b31560 PA |
3 | # |
4 | # Clean a text file -- or directory of text files -- of stealth whitespace. | |
5 | # WARNING: this can be a highly destructive operation. Use with caution. | |
6 | # | |
7 | ||
cb77f0d6 | 8 | use warnings; |
12b31560 PA |
9 | use bytes; |
10 | use File::Basename; | |
11 | ||
cb3ed5b7 PA |
12 | # Default options |
13 | $max_width = 79; | |
14 | ||
12b31560 PA |
15 | # Clean up space-tab sequences, either by removing spaces or |
16 | # replacing them with tabs. | |
17 | sub clean_space_tabs($) | |
18 | { | |
19 | no bytes; # Tab alignment depends on characters | |
20 | ||
21 | my($li) = @_; | |
22 | my($lo) = ''; | |
23 | my $pos = 0; | |
24 | my $nsp = 0; | |
25 | my($i, $c); | |
26 | ||
27 | for ($i = 0; $i < length($li); $i++) { | |
28 | $c = substr($li, $i, 1); | |
29 | if ($c eq "\t") { | |
30 | my $npos = ($pos+$nsp+8) & ~7; | |
31 | my $ntab = ($npos >> 3) - ($pos >> 3); | |
32 | $lo .= "\t" x $ntab; | |
33 | $pos = $npos; | |
34 | $nsp = 0; | |
35 | } elsif ($c eq "\n" || $c eq "\r") { | |
36 | $lo .= " " x $nsp; | |
37 | $pos += $nsp; | |
38 | $nsp = 0; | |
39 | $lo .= $c; | |
40 | $pos = 0; | |
41 | } elsif ($c eq " ") { | |
42 | $nsp++; | |
43 | } else { | |
44 | $lo .= " " x $nsp; | |
45 | $pos += $nsp; | |
46 | $nsp = 0; | |
47 | $lo .= $c; | |
48 | $pos++; | |
49 | } | |
50 | } | |
51 | $lo .= " " x $nsp; | |
52 | return $lo; | |
53 | } | |
54 | ||
cb3ed5b7 PA |
55 | # Compute the visual width of a string |
56 | sub strwidth($) { | |
57 | no bytes; # Tab alignment depends on characters | |
58 | ||
59 | my($li) = @_; | |
60 | my($c, $i); | |
61 | my $pos = 0; | |
62 | my $mlen = 0; | |
63 | ||
64 | for ($i = 0; $i < length($li); $i++) { | |
65 | $c = substr($li,$i,1); | |
66 | if ($c eq "\t") { | |
67 | $pos = ($pos+8) & ~7; | |
68 | } elsif ($c eq "\n") { | |
69 | $mlen = $pos if ($pos > $mlen); | |
70 | $pos = 0; | |
71 | } else { | |
72 | $pos++; | |
73 | } | |
74 | } | |
75 | ||
76 | $mlen = $pos if ($pos > $mlen); | |
77 | return $mlen; | |
78 | } | |
79 | ||
12b31560 PA |
80 | $name = basename($0); |
81 | ||
cb3ed5b7 PA |
82 | @files = (); |
83 | ||
84 | while (defined($a = shift(@ARGV))) { | |
85 | if ($a =~ /^-/) { | |
86 | if ($a eq '-width' || $a eq '-w') { | |
87 | $max_width = shift(@ARGV)+0; | |
88 | } else { | |
89 | print STDERR "Usage: $name [-width #] files...\n"; | |
90 | exit 1; | |
91 | } | |
92 | } else { | |
93 | push(@files, $a); | |
94 | } | |
95 | } | |
96 | ||
97 | foreach $f ( @files ) { | |
12b31560 PA |
98 | print STDERR "$name: $f\n"; |
99 | ||
100 | if (! -f $f) { | |
101 | print STDERR "$f: not a file\n"; | |
102 | next; | |
103 | } | |
104 | ||
105 | if (!open(FILE, '+<', $f)) { | |
106 | print STDERR "$name: Cannot open file: $f: $!\n"; | |
107 | next; | |
108 | } | |
109 | ||
110 | binmode FILE; | |
111 | ||
112 | # First, verify that it is not a binary file; consider any file | |
113 | # with a zero byte to be a binary file. Is there any better, or | |
114 | # additional, heuristic that should be applied? | |
115 | $is_binary = 0; | |
116 | ||
117 | while (read(FILE, $data, 65536) > 0) { | |
118 | if ($data =~ /\0/) { | |
119 | $is_binary = 1; | |
120 | last; | |
121 | } | |
122 | } | |
123 | ||
124 | if ($is_binary) { | |
125 | print STDERR "$name: $f: binary file\n"; | |
126 | next; | |
127 | } | |
128 | ||
129 | seek(FILE, 0, 0); | |
130 | ||
131 | $in_bytes = 0; | |
132 | $out_bytes = 0; | |
133 | $blank_bytes = 0; | |
134 | ||
135 | @blanks = (); | |
136 | @lines = (); | |
cb3ed5b7 | 137 | $lineno = 0; |
12b31560 PA |
138 | |
139 | while ( defined($line = <FILE>) ) { | |
cb3ed5b7 | 140 | $lineno++; |
12b31560 PA |
141 | $in_bytes += length($line); |
142 | $line =~ s/[ \t\r]*$//; # Remove trailing spaces | |
143 | $line = clean_space_tabs($line); | |
144 | ||
145 | if ( $line eq "\n" ) { | |
146 | push(@blanks, $line); | |
147 | $blank_bytes += length($line); | |
148 | } else { | |
149 | push(@lines, @blanks); | |
150 | $out_bytes += $blank_bytes; | |
151 | push(@lines, $line); | |
152 | $out_bytes += length($line); | |
153 | @blanks = (); | |
154 | $blank_bytes = 0; | |
155 | } | |
cb3ed5b7 PA |
156 | |
157 | $l_width = strwidth($line); | |
158 | if ($max_width && $l_width > $max_width) { | |
159 | print STDERR | |
160 | "$f:$lineno: line exceeds $max_width characters ($l_width)\n"; | |
161 | } | |
12b31560 PA |
162 | } |
163 | ||
164 | # Any blanks at the end of the file are discarded | |
165 | ||
166 | if ($in_bytes != $out_bytes) { | |
167 | # Only write to the file if changed | |
168 | seek(FILE, 0, 0); | |
169 | print FILE @lines; | |
170 | ||
171 | if ( !defined($where = tell(FILE)) || | |
172 | !truncate(FILE, $where) ) { | |
173 | die "$name: Failed to truncate modified file: $f: $!\n"; | |
174 | } | |
175 | } | |
176 | ||
177 | close(FILE); | |
178 | } |