linux shell中的if [ ! -f /etc/dnsmasq.conf ]是什么意思?

Question

代码如下图所示

if [ ! -f /etc/dnsmasq.conf ]; then
echo "警告！dnsmasq安装失败！"
read
fi

if [ ! -d /etc/openvpn ]; then
echo "警告！OpenVPN安装失败！"
read
fi

谁能讲解一下这个if [ ! -f /etc/dnsmasq.conf ]和-d分别是什么意思？

Answer 1

-a file exists.
-b file exists and is a block special file.
-c file exists and is a character special file.
-d file exists and is a directory.
-e file exists (just the same as -a).
-f file exists and is a regular file.
-g file exists and has its setgid(2) bit set.
-G file exists and has the same group ID as this process.
-k file exists and has its sticky bit set.
-L file exists and is a symbolic link.
-n string length is not zero.
-o Named option is set on.
-O file exists and is owned by the user ID of this process.
-p file exists and is a first in, first out (FIFO) special file or
named pipe.
-r file exists and is readable by the current process.
-s file exists and has a size greater than zero.
-S file exists and is a socket.
-t file descriptor number fildes is open and associated with a
terminal device.
-u file exists and has its setuid(2) bit set.
-w file exists and is writable by the current process.
-x file exists and is executable by the current process.
-z string length is zero.