How to call a shell function

Question

How can I use the integer value returned by a function in shell script that takes some arguments as input?

I am using the following code:

fun()
{
 echo "hello ${1}"
 return 1
}
a= fun 2
echo $a

I am not sure how should I call this function. I tried the methods below, bot none of them seems to work:

a= fun 2
a=`fun 2`
a=${fun 2}

Answer 1

The exit code is contained in $?:

fun 2
a=$?

Answer 2

you may have a look at the following question: https://stackoverflow.com/questions/8742783/returning-value-from-called-function-in-shell-script with a long and well explained answer. Regards.

• terdon: Welcome to Unix & Linux Stack Exchange! While this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference.

Answer 3

#!/bin/bash
function producer_func()
{
 echo "1"
 echo "[ 1ドル ]"
 echo "2"
 echo "3"
}
function returner_func()
{
 echo "output from returner_func"
 return 1
}
#just print to stdout from function
producer_func "aa ww"
echo "--------------------"
#accumulate function output into variable
some_var=$(producer_func "bbb ccc")
echo -e "<$some_var>"
echo "--------------------"
#get returned value from function, may be integer only
returner_func
echo "returner_func returned $?"
echo "--------------------"
#accumulate output and get return value
some_other_var=`returner_func`
echo "<$some_other_var>"
echo "returner_func returned $?"
echo "--------------------"

nice bash tutorial, link points to functions invocation

• Wildcard: FYI, this uses a nonstandard function definition syntax.