同文件检测(file tests)一样，stat和lstat的默认参数为$_，意指stat系统调用将针对$_所对应的文件进行操作。
基于4个网页-相关网页
Some of the more common file tests are shown in Table 1.
表1显示了一些更常见的文件测试。
youdao
In September 2002, Pfizer said it would have to wait another year to file as it conducted tests related to tumors in mice.
FORBES: Pfizer's Disappointing Victory
应用推荐
模块上移
模块下移
不移动