test (arguments)

Question 1

True if FILE exists.

Answer 1

[ -a FILE ]

Question 2

True if FILE exists and is a block-special file.

Answer 2

[ -b FILE ]

Question 3

True if FILE exists and is a character-special file.

Answer 3

[ -c FILE ]

Question 4

True if FILE exists and is a directory.

Answer 4

[ -d FILE ]

Question 5

True if FILE exists.

Answer 5

[ -e FILE ]

Question 6

True if FILE exists and is a regular file.

Answer 6

[ -f FILE ]

Question 7

True if FILE exists and its SGID bit is set.

Answer 7

[ -g FILE ]

Question 8

True if FILE exists and is a symbolic link.

Answer 8

[ -h FILE ]

Question 9

True if FILE exists and its sticky bit is set.

Answer 9

[ -k FILE ]

Question 10

True if FILE exists and is a named pipe (FIFO).

Answer 10

[ -p FILE ]

Question 11

True if FILE exists and is readable.

Answer 11

[ -r FILE ]

Question 12

True if FILE exists and has a size greater than zero.

Answer 12

[ -s FILE ]

Question 13

True if file descriptor FD is open and refers to a terminal.

Answer 13

[ -t FD ]

Question 14

True if FILE exists and its SUID (set user ID) bit is set.

Answer 14

[ -u FILE ]

Question 15

True if FILE exists and is writable.

Answer 15

[ -w FILE ]

Question 16

True if FILE exists and is executable.

Answer 16

[ -x FILE ]

Question 17

True if FILE exists and is owned by the effective user ID.

Answer 17

[ -O FILE ]

Question 18

True if FILE exists and is owned by the effective group ID.

Answer 18

[ -G FILE ]

Question 19

True if FILE exists and is a symbolic link.

Answer 19

[ -L FILE ]

Question 20

True if FILE exists and has been modified since it was last read.

Answer 20

[ -N FILE ]

Question 21

True if FILE exists and is a socket.

Answer 21

[ -S FILE ]

Question 22

True if FILE1 has been changed more recently than FILE2, or if FILE1 exists and FILE2 does not.

Answer 22

[ FILE1 -nt FILE2 ]

Question 23

True if FILE1 is older than FILE2, or is FILE2 exists and FILE1 does not.

Answer 23

[ FILE1 -ot FILE2 ]

Question 24

True if FILE1 and FILE2 refer to the same device and inode numbers.

Answer 24

[ FILE1 -ef FILE2 ]

Question 25

True if shell option “OPTIONNAME” is enabled.

Answer 25

[ -o OPTIONNAME ]

Question 26

True if the length of “STRING” is zero.

Answer 26

[ -z STRING ]

Question 27

True if the length of “STRING” is non-zero.

Answer 27

[ -n STRING ] or [ STRING ]

Question 28

True if the strings are equal. “=” may be used instead of “==” for strict POSIX compliance.

Answer 28

[ STRING1 == STRING2 ]

Question 29

True if the strings are not equal.

Answer 29

[ STRING1 != STRING2 ]

Question 30

True if “STRING1” sorts before “STRING2” lexicographically in the current locale.

Answer 30

[ STRING1 < STRING2 ]

Question 31

True if “STRING1” sorts after “STRING2” lexicographically in the current locale.

Answer 31

[ STRING1 > STRING2 ]

Question 32

True if EXPR is false.

Answer 32

[ ! EXPR ]

Question 33

Returns the value of EXPR. This may be used to override the normal precedence of operators.

Answer 33

[ ( EXPR ) ]

Question 34

True if both EXPR1 and EXPR2 are true.

Answer 34

[ EXPR1 -a EXPR2 ]

Question 35

True if either EXPR1 or EXPR2 is true.

Answer 35

[ EXPR1 -o EXPR2 ]