UNIX® Shells by Example, Third Edition

test—evaluates an expression

test evaluates an expression and returns an exit status indicating that the expression is either true (zero) or false (not zero). Used primarily by Bourne and Korn shell for string, numeric, and file testing. The C shell has most of the tests built-in.

Example A.49.

1 test 5 gt 6 2 echo $? ( Bourne and Korn Shells) (Output is 1, meaning the result of the test is not true.)

EXPLANATION The test command performs an integer test to see if 5 is greater than 6. The $? variable contains the exit status of the last command. If a nonzero status is reported, the test results are not true; if the return status is zero, the the test result is true.