> (and many shells have a legacy behavior of running a file as a script if it doesn't start with a #! line.) execlp and execvp are actually guaranteed to do th

> (and many shells have a legacy behavior of running a file as a script if it doesn't start with a #! line.) execlp and execvp are actually guaranteed to do this in POSIX-2017, although shells might also do this themselves if they resolve $PATH by themselves.