Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: c00c69b9171a216046682d8681bfd51fb6d4d4d4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#!/usr/bin/env perl
# SPDX-License-Identifier: GPL-2.0
#
# Clean a text file -- or directory of text files -- of stealth whitespace.
# WARNING: this can be a highly destructive operation.  Use with caution.
#

use warnings;
use bytes;
use File::Basename;

# 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);
}