perl正则表达式基础的问题
$_ = "Hello there,nerghbor ";
if (/(\w+),/) {
print "the word was $1\n ";
}

为什么$1=there 而不是Hello呢？

[解决办法]
因为还需要匹配后面的一个 ', '，改成如下即可：

$_ = "Hello there,nerghbor ";
if (/(\w+)/) {
print "the word was $1\n ";
}