Regular Expression

#!/bin/bash


STR="12345A"
REG="[a-z]{0,4}[0-9]{2,8}[A-Z]"


if [[ $STR =~ $REG ]]; then



{0,3} -  This specify the preceding character set should be in length 0 upto 3.
{2,8} - This specified the length of character should be in length 2 to 8


=~ - This is how to compare regular expression pattern with a string in bash