# test

`[[` <test> `]]`   is better, it's a shell keyword

## test operators

Below, the tests marked with `:!:` are non-standard tests

```
Operator syntax 	Description 	
-a <FILE> 	True if <FILE> exists. :!: (not recommended, may collide with -a for AND, see below) 	
-e <FILE> 	True if <FILE> exists. 	
-f <FILE> 	True, if <FILE> exists and is a regular file. 	
-d <FILE> 	True, if <FILE> exists and is a directory.
-c <FILE> 	True, if <FILE> exists and is a character special file. 	
-b <FILE> 	True, if <FILE> exists and is a block special file. 	
-p <FILE> 	True, if <FILE> exists and is a named pipe (FIFO). 	
-S <FILE> 	True, if <FILE> exists and is a socket file. 	
-L <FILE> 	True, if <FILE> exists and is a symbolic link. 	
-h <FILE> 	True, if <FILE> exists and is a symbolic link. 	
-g <FILE> 	True, if <FILE> exists and has sgid bit set. 	
-u <FILE> 	True, if <FILE> exists and has suid bit set. 	
-r <FILE> 	True, if <FILE> exists and is readable. 	
-w <FILE> 	True, if <FILE> exists and is writable. 	
-x <FILE> 	True, if <FILE> exists and is executable. 	
-s <FILE> 	True, if <FILE> exists and has size bigger than 0 (not empty). 	
-t <fd> 	True, if file descriptor <fd> is open and refers to a terminal. 	
<FILE1> -nt <FILE2> 	True, if <FILE1> is newer than <FILE2> (mtime). :!: 	
<FILE1> -ot <FILE2> 	True, if <FILE1> is older than <FILE2> (mtime). :!: 	
<FILE1> -ef <FILE2> 	True, if <FILE1> and <FILE2> refer to the same device and inode numbers. :!:
```