Originally Posted by gazagelen
nope nothing happened i tried to put double or single quote but problem is same. i don't have any problem with other operators by the way
Did you put quotes around both test operands as in
elif test "$oper" = '*'; then
That should have worked. The test command and its alternate implementation [ ], are more prone to this sort of trouble than the later test facility [[ ]] for reasons explained here
so you can get off to a good start learning shell scripting by getting into the habit of using [[ ]] instead of test
. What are you using to learn shell scripting? If it advises using the test command you would be better off with something else (unless you want to write scripts to run under older or simpler shells that bash).