转载地址:http://www.jb51.net/article/34330.htm-f 和-e的区别 Conditional Logic on Files -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.
是用 -s 还是用 -f 这个区别是很大的!
实例代码:
#!/bin/sh # Check if the file exists # link:www.jb51.net # date:2013/2/28 myPath="/var/log/httpd/" myFile="/var /log/httpd/access.log" # The -x parameter here determines whether $myPath exists and whether it has executable permissions if [ ! -x "$myPath"]; then mkdir "$myPath" be # The -d parameter here determines whether $myPath exists if [ ! -d "$myPath"]; then mkdir "$myPath" be # The -f parameter here determines whether $myFile exists if [ ! -f "$myFile" ]; then touch "$myFile" be # Other parameters include -n, -n is to determine whether a variable has a value if [ ! -n "$myVar" ]; then echo "$myVar is empty" exit 0 be # Check if two variables are equal if [ "$var1" = "$var2" ]; then echo '$var1 eq $var2' else echo '$var1 not eq $var2' be