Well, that's me told. I've used fgrep since the days when regular grep on a large file would take minutes, while fgrep would take seconds. I also learned egrep's slightly weird syntax at the same time. This was before PCRE was a thing. Before long-form options were a thing, too

Deprecation of free software is so pointless. To break scripts for some imagined purity is flat-out daft. 

 Stewart