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by ilyt 1087 days ago 

    /some/../path
should pretty much 100% of the time be disallowed, there is no sensible use case that is not "someone wrote ugly code"

../some/path makes sense sometimes at least

... but I'd imagine it wouldn't as useful as you think it is, because many apps resolve .. before passing it to the OS
1 comments
vbezhenar 1087 days ago
I don't agree. Those kinds of paths are often result of concatenation of several configuration options. Like APP_DIR=/some/app/bin; LOG_DIR="$APP_DIR/../logs". And APP_DIR comes to you from distro scripts, so you're not going to fork those scripts and support your own fork across updates, you just build upon those scripts.
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im3w1l 1087 days ago
The whole point of having an APP_DIR option is so that you can change it and things will just keep working. By doing $APP_DIR/.. you invalidate that by making assumptions about the parent structure. In particular something that could easily happen in the future is that you may not have write access to "$APP_DIR/.." You gotta do what you gotta do, but it is smelly.
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ilyt 1087 days ago
Then you have fucked up your app config.

If user gives your app a directory to play with, exiting that dir via ../something is the last thing you should do, it's horrible malpractice that just causes annoyance

"distro scripts" near always just show direct path to /var/lib/something for data and /usr/something for rest.

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