kalendar by johnburn

#!/usr/bin/perl
use integer;

%nama_bulan = (
"jan" => 1,  "feb" => 2,  "mar" => 3,  "apr" => 4,
"may" => 5,  "jun" => 6,  "jul" => 7,  "aug" => 8,
"sep" => 9,  "oct" => 10, "nov" => 11, "dec" => 12,
);
@bulan = ("",
  " Januari", " Februari",   "  Mac",   "  April",
    "   May",    "  Jun",    "  Julai",  "  Ogos",
"September",  " Oktober", " November", " Disember"
);
@max_hari = (0,31,28,31,30,31,30,31,31,30,31,30,31);

print "Sila masukkan bulan: ";
$bulan_input = <>;
if ($bulan_input =~ /^ *\d{1,2} *$/) {
  die "Bulan mesti diantara 1 dan 12!\n" unless ($bulan_input>=1 && $bulan_input<=12);
} else {
  $bulan_input = $nama_bulan{lc(substr($bulan_input,0,3))};
  die "Nama bulan tidak tepat: $ARGV[0]!\n" unless defined($bulan_input);
}
print "Sila masukkan tahun: ";
$tahun = <>;
die "Tahun tidak tepat: $tahun!\n" unless $tahun =~ /^ *\d{4} *$/;
$tahun = int($tahun);
die "Tahun mesti lebih besar dari 0!\n" unless $tahun>0;
print "\n\t$bulan[$bulan_input] $tahun\n\nSun  Mon  Tue  Wed  Thu  Fri  Sat\n";
$max_hari[2] = 29 if ($tahun%400==0) || (($tahun%4==0) && ($tahun%100!=0));
--$tahun;
$st = 1 + $tahun*365 + $tahun/4 - $tahun/100 + $tahun/400;
for ($i=1; $i<$bulan_input; ++$i) {
  $st += $max_hari[$i];
}
$st %= 7;
for ($i=0; $i<$st; ++$i) {
  print "     ";
}
for ($i=1; $i<=$max_hari[$bulan_input]; ++$i) {
  printf "%3d  ", $i;
  print "\n" if ($st+$i)%7==0;
}
print "\n\n";