hweily

#!/usr/bin/perl
# name.pl
$pre_a =$ARGV[0];

$pre_b =$ARGV[0];

$name = $pre_a || $pre_b;

print "$name \n";


---------------------------------
[root@user]# ./name.pl jason

[root@user]j#jason

[root@user]# ./name.pl '' jean

[root@user]j#jean

------------------------------------------------------------------

#!/usr/bin/perl
# name.pl

$name =$ARGV[0];

$pre_b ='jason';

$name ||= $pre_b;

print "$name \n";


---------------------------------
[root@user]# ./name.pl steven

[root@user]j#steven

[root@user]# ./name.pl

[root@user]j#jason