Thank you So much Corona !
Now it works, i'm totally confused with that QuoteDoubleQuoteBackQuoteUnderQuote syntax, but this now just works like a charms

I really have to learn how to manage this !

Just to confirm, here the final syntax :

Code:

returnedStr= "`mysql -u theuser --password=thepassword < dump.sql 2>&1`"
if [[ -n "$returnedStr" ]] ; then
  echo ERROR READING DUMP:  $returnedStr
  exit 1
 else
  echo cool ($returnedStr)
 fi

CGPicket > well UNIX shell sounds Armish stylelife when you discover it

Thanks again people.