build: add zoneinfo2ucode.pl

Add a zoneinfo2ucode.pl script which is the ucode equivalent to
zoneinfo2lua.pl. It will generate a ucode module exporting a dictionary
of known timezone names and their corresponding TZ strings.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/build/zoneinfo2ucode.pl b/build/zoneinfo2ucode.pl
new file mode 100755 (executable)
index 0000000..35dfac3
--- /dev/null
+++ b/build/zoneinfo2ucode.pl
@@ -0,0 +1,93 @@
+#!/usr/bin/perl
+# zoneinfo2ucode.pl - Make ucode module from /usr/share/zoneinfo
+# Execute from within root of Luci feed, usually feeds/luci
+
+use strict;
+
+my %TZ;
+
+my $tzdin  = $ARGV[0] || "/usr/share/zoneinfo";
+my $tzdout = $ARGV[1] || "./modules/luci-base-ucode/ucode/zoneinfo.uc";
+
+local $/ = "\012";
+open( ZTAB, "< $tzdin/zone.tab" ) || die "open($tzdin/zone.tab): $!";
+
+while( ! eof ZTAB ) {
+       chomp( my $line = readline ZTAB );
+       next if $line =~ /^#/ || $line =~ /^\s+$/;
+
+       my ( undef, undef, $zone, @comment ) = split /\s+/, $line;
+
+       printf STDERR "%-40s", $zone;
+
+       if( open ZONE, "< $tzdin/$zone" ) {
+               seek ZONE, -2, 2;
+
+               while( tell(ZONE) > 0 ) {
+                       read ZONE, my $char, 1;
+                       ( $char eq "\012" ) ? last : seek ZONE, -2, 1;
+               }
+
+               chomp( my $tz = readline ZONE );
+               print STDERR ( $tz || "(no tzinfo found)" ), "\n";
+               close ZONE;
+
+               if( $tz ) {
+                       $zone =~ s/_/ /g;
+                       $TZ{$zone} = $tz;
+               }
+       }
+       else
+       {
+               print STDERR "open($tzdin/$zone): $!\n";
+       }
+}
+
+close ZTAB;
+
+# Add Etc/GMT zones from manually as they are not in zone.tab
+$TZ{"Etc/GMT"} = "GMT0";
+$TZ{"Etc/GMT-1"} = "<+01>-1";
+$TZ{"Etc/GMT-2"} = "<+02>-2";
+$TZ{"Etc/GMT-3"} = "<+03>-3";
+$TZ{"Etc/GMT-4"} = "<+04>-4";
+$TZ{"Etc/GMT-5"} = "<+05>-5";
+$TZ{"Etc/GMT-6"} = "<+06>-6";
+$TZ{"Etc/GMT-7"} = "<+07>-7";
+$TZ{"Etc/GMT-8"} = "<+08>-8";
+$TZ{"Etc/GMT-9"} = "<+09>-9";
+$TZ{"Etc/GMT-10"} = "<+10>-10";
+$TZ{"Etc/GMT-11"} = "<+11>-11";
+$TZ{"Etc/GMT-12"} = "<+12>-12";
+$TZ{"Etc/GMT-13"} = "<+13>-13";
+$TZ{"Etc/GMT-14"} = "<+14>-14";
+$TZ{"Etc/GMT+1"} = "<-01>1";
+$TZ{"Etc/GMT+2"} = "<-02>2";
+$TZ{"Etc/GMT+3"} = "<-03>3";
+$TZ{"Etc/GMT+4"} = "<-04>4";
+$TZ{"Etc/GMT+5"} = "<-05>5";
+$TZ{"Etc/GMT+6"} = "<-06>6";
+$TZ{"Etc/GMT+7"} = "<-07>7";
+$TZ{"Etc/GMT+8"} = "<-08>8";
+$TZ{"Etc/GMT+9"} = "<-09>9";
+$TZ{"Etc/GMT+10"} = "<-10>10";
+$TZ{"Etc/GMT+11"} = "<-11>11";
+$TZ{"Etc/GMT+12"} = "<-12>12";
+
+open(O, "> $tzdout") || die "open($tzdout): $!\n";
+
+print STDERR "Writing time zones to $tzdout ... ";
+print O <<HEAD;
+// Autogenerated by zoneinfo2ucode.pl
+
+export default {
+HEAD
+
+foreach my $zone ( sort keys %TZ ) {
+       printf O "\t'%s': '%s',\n", $zone, $TZ{$zone}
+}
+
+print O "};\n";
+close O;
+
+print STDERR "done\n";