For over a year, I've started using:
#!/usr/bin/env perl
instead of using direct perl path.
I've read, that env finds an executable from locations in PATH variable, which command also does, but it might resolve to not first encountered path with the named binary, but the best for context, so I've looked @ man which to see what other parameters it has, since env (I didn't find a way for it to just to show the paths, that it resolves), which has -a, that allows to show all possible paths, so I did:
which -a perl
It gave me only one path:
/usr/bin/perl