将第二个参数传递给Bash函数

How would I pass the 2nd argument into a bash function called setdb? I ask the user to enter a command. If the user enters setdb test, I want to pass test into the function setdb. Then I want to run a file test on it to see if test.txt exists.

#!/bin/bash

#Setdb. Checks if the file exist, read, does not exist, 
setdb () {
    if [[ -e $FILE && -r $FILE ]]; then 
        echo "Database set to" $FILE
    elif [! -f $FILE  && -w $FILE ]; then
        touch datbase.txt
        echo "File database created. Database set to database.txt"
    fi
}

while read answer; do
    if [[ $answer == "setdb" ]]; then 
        setdb
    fi
done