Shell - calling function with nc -c - shell

Question

This is my Server-Code for now.
I just want to get Data from a Client, analyze it and send my answer.
Is there a way to call my function managedata() in nc? My Code, obviously doesn't work.
server.sh:
managedata()
{
echo $1
#do something with data
return $1
}
listen()
{
echo "Server listening.."
nc -l -p 1234 -c '$(read i && managedata $i && echo $?)'
}
#MAIN
while true;
do
listen
done
Client.sh:
send()
{
echo $1 | nc $ip $port -o 0
}
#
register()
{
read -p "Login: " usrname
echo -n "Password: "
read -s password | shasum > password
#Schleife zum encrypten des Passworts
#Count = n -> Leslie Lamport Alogrithmus
n=5
count=$n
while [ $count -ge 2 ]
do
password="$(cat password | shasum)"
((count--))
done
password=`cat password`
echo
echo $password
data="reg-$usrname-$n-$password"
send $data
}
#
log()
{
echo "..."
}
#
menue()
{
echo "====== Lab: Shell Programming (BS) ======"
echo " r Register"
echo " l Login"
echo " q Quit"
echo
read -p "your choice: " check
case "$check" in
r) register;;
l) log;;
q) exit;;
esac
}
#MAIN
ip=$1
port=$2
while true
do
menue
done
bash -x server.sh:
+ true
+ listen
+ echo 'Server listening..'
Server listening..
+ nc -l -p 1234 -c '$(read i && managedata $i && echo $?)'
sh: 1: managedata: not found
+ true
+ listen
+ echo 'Server listening..'
Server listening..
+ nc -l -p 1234 -c '$(read i && managedata $i && echo $?)'

Answer 1

Yep you should "tell" bash to treat managedata as command or function that can be executed.
BTW, you need to use $() to execute whole expression not only managedata:
nc -l -p 1234 -c $(read i && managedata $i && echo $?)
Also bash can't return strings, only integer error codes, so return $1 won't work if it's not integer in range of 0 - 255.
Replace to return 0