Returning values from a bash function

Linux / By

bash does not provide a return statement to return custom values from a function. The return statement is only used to return a numeric status code to the calling function which can be retrieved with $?. Long story made short, use a recent bash version (>= 4.3) and use the declare -n statement to declare a reference to the variable where the result will be stored, and pass the name of this variable as a parameter to the function: 

#!/bin/bash

someFunction() {
    declare -n __resultVar=$1
    local someValue="Hello World"

    # The next statement assigns the value of the local variable to the variable
    # passed as parameter
    __resultVar=${someValue}
}

# call the function and pass the name of the result variable
someFunction theResult
echo ${theResult}