longDate=$(echo ${#date})
lol=0
crypture=""
while test $lol -lt $longDate
do
caractere=$(echo ${date:$lol:1})
case $caractere in
0) crypture=$(echo $crypture"z");;
1) crypture=$(echo $crypture"a");;
2) crypture=$(echo $crypture"b");;
3) crypture=$(echo $crypture"c");;
4) crypture=$(echo $crypture"d");;
5) crypture=$(echo $crypture"e");;
6) crypture=$(echo $crypture"f");;
7) crypture=$(echo $crypture"g");;
8) crypture=$(echo $crypture"h");;
9) crypture=$(echo $crypture"i");;
*) echo"la date de naissance en est pas une: erreur"
			exit;;
esac
lol=$(($lol+1))
done