在perl中,if语句中的-f是什么意思？

Question

 my $Path = $_[0];
 return "" if(not $Path or not -f $Path);

我正在浏览perl文件而无法理解-f选项意味着什么不是-f意味着什么？

Answer 1

该-f运营商测试其操作数是否是一个普通的文件,而不是一个目录,符号链接,或其他特殊文件.

所有以a开头的运算符-都称为文件测试运算符,通常也可以在shell脚本语言中找到.它们是一元运算符(仅占一个操作数),类似于!或是~一元运算符.

Answer 2

-r   readable
-w   writable
-x   executable
-o   owned by  user
-R   readable by this  user or group
-W   writable by user or group
-X   executable by this  user or group
-O   owned by this  user
-e   File or directory name exists
-z   File exists and has zero size
-s   exists and has nonzero size (the value is the size in bytes)
-f   plain file
-d   directory
-l   symbolic link
-S   socket