linux shell 判断文件是否存在等符号

-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. （常用）

-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.

例子：

if [ -f "$LOG/cws_inv.data" ];then
rm $LOG/cws_inv.data
fi

注意：文件最好用”“括起来。