Linux shell script, checking input from user -

so i'm making simple bash shell script calculator , ran snag.

i can't seem find out see if user has inputted + or - or / or *

i'm not sure should try write. know

echo "enter + or - " read input2 if [ $input2 = "+" ]     echo "you entered $input2" 

doesn't work. should put read basic operators?

edit: bash shell being used

in bash, semicolon or newline needed before then.

double quotes variables prevent expansion might lead syntax errors:

if [ "$input" = '+' ] ; 

you can switch [[ ... ]] conditionals don't require quoting of arguments:

if [[ $input = + ]] ;     echo entered + fi 

you have quote * on right hand side, though, otherwise it's interpreted wildcard pattern, meaning "anything".