bash Pocket Reference

Name

test — Evaluate conditions, for use in loops and conditionals.

Synopsis

test condition
[ condition ]
[[ condition ]]

Evaluate a condition and, if its value is true, return a zero exit status; otherwise, return a nonzero exit status. An alternate form of the command uses [ ] rather than the word test. An additional alternate form uses [[ ]], in which case word splitting and pathname expansion are not done (see [[ ]]). condition is constructed using the following expressions. Conditions are true if the description holds true.

File Conditions

-a file	file exists. (Deprecated; use -e instead.)
-b file	file exists and is a block special file.
-c file	file exists and is a character special file.
-d file	file exists and is a directory.
-e file	file exists. (Same as -a, for POSIX compatibility.)
-f file	file exists and is a regular file.
-g file	file exists, and its set-group-id bit is set.
-G file	file exists, and its group is the effective group ID.
-h file	file exists and is a symbolic link. (Same as -L.)
-k file	file exists, and its sticky bit is set.
-L file	file exists and is a symbolic link. (Same as -h.)
-N file	file exists and was modified after it was last read.
-O file	file exists, and its owner is the effective user ID.
-p file	file exists and is a named pipe (FIFO).
-r file	file exists and is readable.
-s file	file exists and has a size greater than zero.
-S file	file exists and is a socket.
-t [n]	The open file descriptor n is associated ...