perl encode_utf8 decode_utf8

[oracle@oadb ~]$ echo $LANG
en_US.UTF-8

[oracle@oadb ~]$ cat k1.pl 
use Encode;
my $a="测试环境";

print "1111111$a is $a
";

  $a=encode_utf8($a);
print "22222222$a is $a
";
  $a=decode_utf8($a);
print "333333333$a is $a
";

[oracle@oadb ~]$ perl k1.pl 
1111111$a is 测试环境
22222222$a is ???è???????? 
333333333$a is 测试环境


/****************************

[oracle@oadb ~]$ cat k2.pl 
use Encode;
use utf8;
my $a="测试环境";

print "1111111$a is $a
";

#  $a=encode_utf8($a);
#print "22222222$a is $a
";
#  $a=decode_utf8($a);
#print "333333333$a is $a
";
[oracle@oadb ~]$ perl k2.pl 
Wide character in print at k2.pl line 5.
1111111$a is 测试环境



[oracle@oadb ~]$ cat k2.pl 
use Encode;
use utf8;
my $a="测试环境";


  $a=encode_utf8($a);
print "22222222$a is $a
";
#  $a=decode_utf8($a);
#print "333333333$a is $a
";
[oracle@oadb ~]$ perl k2.pl 
22222222$a is 测试环境
[oracle@oadb ~]$