# hexclock.pl <format>:
#    Display current time in various formats.
#
# b zero padded binary integer
# c ASCII character
# d signed integer
# e exponential notation floating point
# f decimal notation floting point
# o octal integer
# p pointer to memory address where time is stored (non-dynamic)
# u unsigned integer
# x hexadecimal integer (default)

use strict;

my $fmt = shift ||'x';
$fmt='x' unless ($fmt =~ /[bcdefgopu]/) ;
$fmt = "%02$fmt" if ($fmt =~ /[xodu]/) ;
$fmt = "%06$fmt" if ($fmt =~ /b/);
$fmt = "%0$fmt" if ($fmt !~ /%/);

while (1) {
        my ($h,$m,$s) = split ":",`date +%H:%M:%S:`;
        printf "\r$fmt : $fmt : $fmt", $h, $m, $s;
        sleep 1;
}