linux-config-diff

#!/usr/bin/perl -w

#
# © Copyright 2008 by Geert Uytterhoeven
#
# This file is subject to the terms and conditions of the GNU General Public
# License.
#

sub usage()
{
    my $name = $0;
    $name =~ s@.*/@@g;
    die <<EOF;

Usage: $name [options] <config> ...

Valid options:
	-h, --help	Display this help
	-s, --strict    Do not treat unselectable as unselected
EOF
}

%symbols = ();
%settings = ();
%versions = ();

sub read_config()
{
    my $file = $_[0];

    open(IN, "<$file") or die "Cannot open config file $file,";
    while (defined($line = <IN>)) {
	chomp($line);
	if (($symbol, $val) = $line =~ /(CONFIG_[A-Za-z0-9_]+)(.*)/) {
	    $val =~ s/^=//;
	    $val =~ s/ is not set/n/;
	    $symbols{$symbol} = $symbol;
	    $settings{$file}{$symbol} = $val;
	} elsif (($version) = $line =~/([^\s]+) Kernel Configuration/) {
	    $versions{$file} = $version;
	}
    }
    close(IN);
}

@files = ();

while (defined($ARGV[0])) {
	$option = $ARGV[0];
	last if not $option =~ /^-/;
	if ($option eq '-h' or $option eq '--help') {
		&usage();
	} elsif ($option eq '-s' or $option eq '--strict') {
		$strict = 1;
	} elsif ($option eq '--') {
		shift @ARGV;
		last;
	} else {
		print STDERR "Unknown option $option\n";
		&usage();
	}
	shift @ARGV;
}

$files = scalar(@ARGV);
&usage if !$files;

for $file (@ARGV) {
    &read_config($file);
}

for $file (@ARGV) {
    next if !defined($versions{$file});
    $version = $versions{$file};
    last;
}
if (defined($version)) {
    for $file (@ARGV) {
	next if !defined($versions{$file});
	if ($versions{$file} ne $version) {
	    print "! $file: version $versions{$file} != $version\n";
	}
    }
}

$maxlen = 0;
for $symbol (keys %symbols) {
    $len = length $symbol;
    $maxlen = $len if $len > $maxlen;
}
for $file (@ARGV) {
    $len = length $file;
    $maxlen = $len if $len > $maxlen;
}

$i = 0;
for $file (reverse @ARGV) {
    $dashes = "-" x ($maxlen + 2*($files - $i) - 1 - length $file);
    print "! $file $dashes+";
    print " |" x $i;
    print "\n";
    $i++;
}
print "!";
print " " x ($maxlen + 2);
for $file (reverse @ARGV) {
    print " |";
}
print "\n";

for $symbol (sort keys %symbols) {
    $same = ' ';
    $val0 = $settings{$ARGV[0]}{$symbol};
    if (!defined($val0)) {
	$val0 = 'n';
    }
    for $file (@ARGV) {
	$val = $settings{$file}{$symbol};
	if (!defined($val)) {
	    if ($strict) {
		$same = '!';
		last;
	    }
	    $val = 'n';
	}
	if ($val ne $val0) {
	    $same = '!';
	    last;
	}
    }
    printf "%s %-*s:", $same, $maxlen, $symbol;
    for $file (@ARGV) {
	if (defined($settings{$file}{$symbol})) {
	    $val = $settings{$file}{$symbol};
	    print " $val";
	} else {
	    print " .";
	}
    }
    print "\n";
}