#!/bin/bash
v=debian123456facile
echo ${v//[1-9]/.}
v1=debian123456facile
echo ${v1//[1-9]*/.}
v2=debian123456facile
echo ${v2//[1-9]*/}
v3=debian123456facile
echo ${v3//[1-9]*/.}
v4=debian123456facile
echo ${v4//*[1-9]/.}
v5=debian123456facile
echo ${v5//[a-z]/x}
v6=debian123456facile
echo ${v6//[a-z 0-9]/x}
echo ${v6//[0-9 a-z]/x}