Do any other shells do it? Afaik it's not part of the POSIX sh spec. So any script that does it is going to be extremely dependent on bash in particular. It wo

Do any other shells do it? Afaik it's not part of the POSIX sh spec. So any script that does it is going to be extremely dependent on bash in particular. It would take actual use cases to convince me it's not a terrible idea. No matter what it's a mechanism to throw arbitrary code into a script that has no say in it. This is not the sort of thing you should do because it seems cool, it should be the sort of thing you do because of a really compelling use case that necessitates it. The fact that afaik no other shell has implemented this behaviour since bash did (a couple of decades ago if I understand correctly?) would rather suggest there is a lack of need for this.