#!/usr/bin/perl;
use strict;
use warnings;
                        #     !     /     u     s     r     /    b      i     n     /
my $buf = pack ('C*', (0x23, 0x21, 0x2F, 0x75, 0x73, 0x72, 0x2f, 0x62, 0x69, 0x6E, 0x2f));

#  $buf is now a sequence of "characters" which are 8 bit unsigned numbers
#  Don't go all crazy with me about multi-byte characters
#  Here "C" means 8 bits, one byte

#  The ASCII characters corresponding to those numbers are:
#  #!/usr/bin/

# to get a particular characters or a group of characters
# from the $buf string, use substr()
#
# substr EXPR,OFFSET,LENGTH,REPLACEMENT
# substr() is often used in conjection with unpack to generate
# a particular numeric value with different byte ordering of say
# a 16 or 32 or 64 bit value

print substr($buf,3,3);  #prints: usr
print "\n";
print substr($buf,7,4);  #prints: bin/
print "\n";

# Now translate each byte in $buf into an array..
# Each 8 bit character will be a represented on my
# computer as a 64 bit signed value in an array of
# what are named "bytes"

my @bytes = unpack ('C*',$buf);

# @bytes is now an array of numbers!

# in decimal values:
print "Decimal Values of \@bytes\n";
print "$_ " for @bytes; print "\n";

# Now to print those bytes in character context:
print "Character values of \@bytes\n";
print chr($_) for @bytes; print "\n";

__END__
usr
bin/
Decimal Values of @bytes
35 33 47 117 115 114 47 98 105 110 47 
Character values of @bytes
#!/usr/bin/