Allow scripts to be run from outside user dir

[rzr]

Change-Id: Ic8aba9e8372d31b6e11399f3500b66842f7a3f7d
Signed-off-by: Philippe Coval [email protected]

[jsoref]

From memory, none of the "obvious" approaches is particularly reliable:

https://stackoverflow.com/questions/242538/unix-shell-script-find-out-which-directory-the-script-file-resides

To deal with this more or less requires a number of changes:

• Switching from posix sh to something else (it's vaguely possible to do this with Bash)

An alternative approach would be to rewrite the code in perl/python/node.js

(I recently ran into a case where npm's nodeenv writes a script that is sh friendly, and the way it does it is by hard coding the absolute path to the installation directory -- alternatively, you can try running it inside bash...)

[jsoref]

FWIW, this fails for the symlink case.

If your path has a directory bin which has a symlink to an f file in a directory spelling (with this repository), this code will resolve the path to bin, whereas the correct path is actually spelling.

Also, while you're probably running on Linux, I use Linux and macOS. On macOS, readlink doesn't have the same -f behavior that people normally suggests to deal w/ that edge.

It's really quite painful to get this right.