Je me mets ça de côté pour gagner du temps la prochaine fois

!/bin/bash

logfile=/tmp/logfile.log
errorfile=/tmp/error.log

function log() {
echo -e "\e[34m\e[1m[$(date +%Y-%m-%d) $(date +%H:%M:%S)] $1\e[0m" | tee -a /tmp/logfile.log
}

function logerror() {
echo -e "\e[91m\e[1m[$(date +%Y-%m-%d) $(date +%H:%M:%S)] $1\e[0m" | tee -a /tmp/logfile.log
}

log "prout"
logerror "pwet"

Je prefere la deuxieme solution :

function myfunc()
{
local myresult='some value'
echo "$myresult"
}

result=$(myfunc) # or result=myfunc
echo $result