Test command in unix doesn't print an output

You get 0 or 1. In the exitcode.

bash-4.2$ test 4 -lt 6

bash-4.2$ echo $?
0

bash-4.2$ test 4 -gt 6

bash-4.2$ echo $?
1

Update: To store the exitcode for later use, just assign it to a variable:

bash-4.2$ test 4 -lt 6

bash-4.2$ first=$?

bash-4.2$ test 4 -gt 6

bash-4.2$ second=$?

bash-4.2$ echo "first test gave $first and the second $second"
first test gave 0 and the second 1

Another way is

test 4 -lt 6 && echo 1 || echo 0

But be careful in that case. If test returns success and echo 1 fails echo 0 will be executed.

If you want the result of a comparison on standard out instead of an exit code, you can use the expr(1) command:

$ expr 4 '<=' 6
1

Two things to note:

1. you will likely need to quote the operator as a lot of them conflict with shell metacharacters
2. the output value is the opposite of the return code for test. test returns 0 for true (which is the standard for exit codes), but expr prints 1 for true.