perl Hash 기본

# 선언 부분
my %_list = (
   'key1' => 0, # 대한통운
   'key2' => 0, # 한진택배
  );
 
  printf "작업 시작\n";
 
# 작업 부분
  while ( my ($key, $value) = each( %_list ) ) {
      print "$key => $value\n";
  }


# 소멸
delete $hash{$key};


# 사이즈
print "size of hash:  " . keys( %hash ) . ".\n";

# function ref return
sub foo
   {
       my ( $login, $p, $uid, $gid, $gecos, $dir, $s );

       my %HoH = ();

       my $file = '/etc/passwd';
       open( PASSWD, "< $file" ) or die "Can't open $file : $!";

       while( <PASSWD> ) {
           ( $login, $p, $uid, $gid, $gecos, $dir, $s ) = split( ':' );

           $HoH{ $login }{ 'uid' } = $uid;
           $HoH{ $login }{ 'gid' } = $gid;
           $HoH{ $login }{ 'dir' } = $dir;
       }

       close PASSWD;

       return \%HoH;
   }