1 files changed, 53 insertions, 0 deletions
diff --git a/challenge-013/pete-houston/perl5/ch-1.pl b/challenge-013/pete-houston/perl5/ch-1.pl
new file mode 100644
index 0000000000..f9915c59e7
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+++ b/challenge-013/pete-houston/perl5/ch-1.pl
@@ -0,0 +1,53 @@
+#!/usr/bin/env perl
+#===============================================================================
+#
+#        FILE: friday.pl
+#
+#        USAGE: ./friday.pl [ YEAR ]
+#
+#  DESCRIPTION: Given a year as argument prints a chronological list of
+#  the last Fridays in each month of that year. Defaults to current year
+#  if argument is missing or invalid
+#
+#===============================================================================
+
+use strict;
+use warnings;
+
+use Time::Piece;
+use Time::Seconds;
+
+my $year = get_year ();
+
+for my $mon (1..12) {
+    print last_friday($year, $mon) . "\n";
+}
+
+sub get_year {
+    my $year = shift @ARGV;
+    if (defined $year) {
+        if ($year =~ /^(\d{4})$/) {
+            if ($year > 1969 && $year < 2039) {
+                return $1;
+            } else {
+                warn "Year $year outside acceptable range 1970-2038\n";
+            }
+        } else {
+            warn "The supplied year ($year) is invalid. Using current year\n";
+        }
+    } else {
+        warn "No year supplied. Using current year\n";
+    }
+    return localtime(time)->year;
+}
+
+sub last_friday {
+    my ($year, $mon) = @_;
+    my $first = sprintf "%i-%2.2i-01", $year, $mon;
+    my $day = Time::Piece->strptime ($first, "%Y-%m-%d");
+    $day += ONE_DAY * ($day->month_last_day - 1);
+
+  while ($day->day_of_week != 5) { $day -= ONE_DAY }
+    return $day->ymd;
+}
+