Perl自动格式输出select 结果

#!/usr/bin/perl
use strict;
use DBI;
my $dbName = 'orcl';
my $dbUser = 'test';
my $dbUserPass = 'test';
my $dbh = DBI->connect("dbi:Oracle:$dbName", $dbUser, $dbUserPass) or die "can't connect to database ";
if ($#ARGV <0){
print "请输入一个参数\n";
exit(-1);
}
my $var=$ARGV[0];
my $sql = $var;

if ($var =~ /select\s+(.+)\s+from\s+.*/i){ $a = $1};
my @arr = (split /,/,"$a");
foreach (@arr){
print "$_"." ";
}
my $sth = $dbh->prepare($sql);
$sth->execute();
while (my  @arr = $sth->fetchrow_array()){
print "\n@arr\n";
}
sh-3.2$ perl a5.pl "SELECT sid,serial# ,module from v\$session" | more
sid serial#  module
1626 521

1627 1421 perl@jhoa (TNS V1-V3)

1630 3

1634 2

1635 1442 SQL*Plus

1640 9

1645 1

1646 1

1647 1

1648 1

1649 1

1650 1

1651 1

1652 1

1653 1

1654 1

1655 1