How to replace a character in a string in BASH?

Question

linux

There is a document (text.csv) that contains lines in the format 1*2*3*4*5. I want to fulfill the condition, if the value in column 4 is different from 0, then replace it with 1.
I wanted to do something like: cat text.csv | awk '{if ($4!=0) and here's a replacement}'.

Help me figure it out please

Answer 1

awk 'BEGIN{OFS=FS="*"}$4!=0{$4=1}{print}' text.csv