Anything other than
”#!/usr/bin/env bash”
is doomed to fail at some time.
if you have /usr/bin/env
> Applications should note that the standard PATH to the shell cannot be assumed to be either /bin/sh or /usr/bin/sh, and should be determined by interrogation of the PATH returned by getconf PATH , ensuring that the returned pathname is an absolute pathname and not a shell built-in.
It's very common for Python. Less so for Bash for two reasons: because the person who writes the script references /bin/sh instead (which is required to be there) even when they are writing bash-isms, or because the person who writes the script assumes that Bash is universally available as /bin/bash.
Other interpreters like python, ruby, etc. have more likelyhood of being used with "virtual environments", so it's more common to use /usr/bin/env with them.
It does get awkward, especially when porting. all your third party libraries and includes are in /usr/local/lib /usr/local/include but at least it is better than freebsd which also insists on putting all third party configs under /usr/local/etc/
So it's not really a standard.
/bin/sh is a much more common convention but once again, not a standard.
There really isn't a truly portable shebang, but the same can be said about executables themselves. As part of the build or install step of whatever thing you're making, you should really be looking these up and changing them.
What's more, bash isn't a standard shell.
> /bin is the "standard" location for bash on a subset of Linux distributions
Considering "location" such that it includes /bin symlinks, that would be nearly all distros, I would think...
> What's more, bash isn't a standard shell.
De facto and specifically among Linux distros, it is. It's probably an underestimate that 95% of all Linux distro installations have it preinstalled.
Bash has to be explicitly installed on OpenBSD, FreeBSD, NetBSD (I think, haven't used it in a while) and probably a bunch of others. And in all of those cases (that I know of) it doesn't end up in /bin/bash once installed.
The default bash shipped on macs is so abhorrently ancient that it would be strictly better if it didn't exist because it would reduce the number of people who think bash scripts I write are broken (they're not broken, they just inevitably depend on some bash 4+ feature). Moreover, hardcoding /bin/bash as your shebang in this case will prevent anyone from remediating this problem by installing a non-ancient bash because the old one in /bin/bash will still get used.
You’re forgetting macOS. It has been using /bin/bash forever.