add a simple maintenance tool for kernel config files

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@5782 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/scripts/config.pl b/scripts/config.pl
new file mode 100755 (executable)
index 0000000..a452537
--- /dev/null
+++ b/scripts/config.pl
@@ -0,0 +1,142 @@
+#!/usr/bin/env perl
+# 
+# Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+use warnings;
+use strict;
+
+my @arg = @ARGV;
+
+sub load_config($) {
+       my $file = shift;
+       my %config;
+
+       open FILE, "$file" or die "can't open file";
+       while (<FILE>) {
+               chomp;
+               /^CONFIG_(.+)=(.+)/ and do {
+                       $config{$1} = $2;
+                       next;
+               };
+               /^# CONFIG_(.+) is not set/ and do {
+                       $config{$1} = -1;
+                       next;
+               };
+               /^#/ and next;
+               /^(.+)$/ and print "WARNING: can't parse line: $1\n";
+       }
+       return \%config;
+}
+
+
+sub config_and($$) {
+       my $cfg1 = shift;
+       my $cfg2 = shift;
+       my %config;
+
+       foreach my $config (keys %$cfg1) {
+               my $val1 = $cfg1->{$config};
+               my $val2 = $cfg2->{$config};
+               $val2 and ($val1 eq $val2) and do {
+                       $config{$config} = $val1;
+               };
+       }
+       return \%config;
+}
+
+
+sub config_add($$) {
+       my $cfg1 = shift;
+       my $cfg2 = shift;
+       my %config;
+       
+       for ($cfg1, $cfg2) {
+               my %cfg = %$_;
+               
+               foreach my $config (keys %cfg) {
+                       $config{$config} = $cfg{$config};
+               }
+       }
+       return \%config;
+}
+
+sub config_diff($$) {
+       my $cfg1 = shift;
+       my $cfg2 = shift;
+       my %config;
+       
+       foreach my $config (keys %$cfg2) {
+               if (!$cfg1->{$config} or $cfg1->{$config} ne $cfg2->{$config}) {
+                       $config{$config} = $cfg2->{$config};
+               }
+       }
+       return \%config
+}
+
+sub config_sub($$) {
+       my $cfg1 = shift;
+       my $cfg2 = shift;
+       my %config = %{$cfg1};
+       
+       foreach my $config (keys %$cfg2) {
+               delete $config{$config};
+       }
+       return \%config;
+}
+
+sub print_cfgline($$) {
+       my $name = shift;
+       my $val = shift;
+       if ($val eq '-1') {
+               print "# CONFIG_$name is not set\n";
+       } else {
+               print "CONFIG_$name=$val\n";
+       }
+}
+
+
+sub dump_config($) {
+       my $cfg = shift;
+       die "argument error in dump_config" unless ($cfg);
+       my %config = %$cfg;
+       foreach my $config (sort keys %config) {
+               print_cfgline($config, $config{$config});
+       }
+}
+
+sub parse_expr($);
+
+sub parse_expr($) {
+       my $pos = shift;
+       my $arg = $arg[$$pos++];
+       
+       die "Parse error" if (!$arg);
+       
+       if ($arg eq '&') {
+               my $arg1 = parse_expr($pos);
+               my $arg2 = parse_expr($pos);
+               return config_and($arg1, $arg2);
+       } elsif ($arg =~ /^\+/) {
+               my $arg1 = parse_expr($pos);
+               my $arg2 = parse_expr($pos);
+               return config_add($arg1, $arg2);
+       } elsif ($arg eq '>') {
+               my $arg1 = parse_expr($pos);
+               my $arg2 = parse_expr($pos);
+               return config_diff($arg1, $arg2);
+       } elsif ($arg eq '-') {
+               my $arg1 = parse_expr($pos);
+               my $arg2 = parse_expr($pos);
+               return config_sub($arg1, $arg2);
+       } else {
+               return load_config($arg);
+       }
+}
+
+my $pos = 0;
+dump_config(parse_expr(\$pos));
+die "Parse error" if ($arg[$pos]);