I too was surprised to see these were shell scripts. I was expecting the grep/fgrep/egrep names to be hard links to the same executable that would check `argv[0]`, as the BSD implementation does.

More interesting than the commit diff is the brief discussion on the bug report from when this all happened a year ago, as referenced in the commit message: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=49996

Sigh. Time to retrain the old fingers again...