Hi,

Thanks for your reply. I just want to make this requirement more clear.
I read values to a variable, using "read var".I am now validating the user input. The user should input the values in the format 1,3,6 (can enter any numeric values upto n).
I have tried this for 2 numbers. This is the command that I had used.
read col
1,2 ----> input provided by user
echo $col | grep -w "^[0-9],[0-9]$"
return code is successful.
If it contains any other input like 1,a or a,1 or a,b it returns a code of 1.

This code works fine for 2 numbers, but I want to make this work for 'n' numbers.
I had tried the solution provided by you, but -E command is not recognised by my script.
TIA