Print echo and return value in bash function

I want print echo in function and return value. It's not working:

function fun1() { echo "Start function" return "2" } echo $(( $(fun1) + 3 )) 

I can only print echo:

function fun1() { echo "Start function" } fun1 

Or I can only return value:

function fun1() { echo "2" # returning value by echo } echo $(( $(fun1) + 3 )) 

But I can't do both.

3 Answers

Well, depending on what you wish, there are several solutions:

1. Print the message to stderr and the value you wish to take in stdout.

   function fun1() { # Print the message to stderr. echo "Start function" >&2 # Print the "return value" to stdout. echo "2" } # fun1 will print the message to stderr but $(fun1) will evaluate to 2. echo $(( $(fun1) + 3 )) 

2. Print the message normally to stdout and use the actual return value with $?.
   Note that the return value will always be a value from 0-255 (Thanks Gordon Davisson).

   function fun1() { # Print the message to stdout. echo "Start function" # Return the value normally. return "2" } # fun1 will print the message and set the variable ? to 2. fun1 # Use the return value of the last executed command/function with "$?" echo $(( $? + 3 )) 

3. Simply use the global variable.

   # Global return value for function fun1. FUN1_RETURN_VALUE=0 function fun1() { # Print the message to stdout. echo "Start function" # Return the value normally. FUN1_RETURN_VALUE=2 } # fun1 will print the message to stdout and set the value of FUN1RETURN_VALUE to 2. fun1 # ${FUN1_RETURN_VALUE} will be replaced by 2. echo $(( ${FUN1_RETURN_VALUE} + 3 )) 

With additional variable (by "reference"):

function fun1() { echo "Start function" local return=$1 eval $return="2" } fun1 result echo $(( result + 3 )) 

A funny resolution could be tailing the last line of fun1() as a returned value:

function fun1() { echo "Start function" echo "return:" echo "2" } # Create a temporary file output=$(mktemp) # Run and redirect the output to console and to file simultaneously fun1 |& tee $output # Get the last line of the file into returnValue returnValue=$(tail -1 $output) echo $(( $returnValue + 3 ))