Bash Test Files

Check That Will Ya?

Bash has a number of expressions for checking file conditions.

Condition expressions are normally used with the builtin '[ ]' and 'test' commands. In truth, '[ ]' is short hand for the 'test' command. You've probably seen it in shell scripts:

if [ some condition ]; then

    do something

fi

Here are the expressions:

-a file    True if file exists

-b file    True if file exists and is blk special file

-c file    True if file exists and is char special file

-d file    True if file exists and is directory

-e file    True if file exists

-f file    True if file exists and is regular file

-g file    True if file exists and is set-gid

-k file    True if file exists and set sticky bit

-p file    True if file exists and is a pipe

-r file    True if file exists and is readable

-s file    True if file exists size > than zero

-t file    True if file exists and open to a terminal

-u file    True if file exists and is set-uid

-w file    True if file exists and is writable

-x file    True if file exists and is executable

-0 file    True if file exists and owned by user-id

-G file    True if file exists and owned by group-id

-L file    True if file exists and is a symbolic link

-S file    True if file exists and is a socket

-N file    True if file exists and modified since read