File Test Operators

A file test operator is a unary operator that tests a filename or a filehandle.

Operator	Meaning
-r	File is readable by effective uid/gid.
-w	File is writable by effective uid/gid.
-x	File is executable by effective uid/gid.
-o	File is owned by effective uid.
-R	File is readable by real uid/gid.
-W	File is writable by real uid/gid.
-X	File is executable by real uid/gid.
-O	File is owned by real uid.
-e	File exists.
-z	File has zero size.
-s	File has non-zero size (returns size).
-f	File is a plain file.
-d	File is a directory.
-l	File is a symbolic link.
-p	File is a named pipe (FIFO).
-S	File is a socket.
-b	File is a block special file.
-c	File is a character special file.
-t	Filehandle is opened to a tty.
-u	File has setuid bit set.
-g	File has setgid bit set.
-k	File has sticky bit set.
-T	File is a text file.
-B	File is a binary file (opposite of -T).
-M	Age of file (at startup) in days since modification.
-A	Age of file (at startup) in days since last access.
-C	Age of file (at startup) in days since inode change.