Hello, what is the failsafe way to determine if my running app has the permission to create a r/w file or a folder without actually creating them? It's on POSIX if the platform matters.
Standard library has only very very basic support for permissions, so to use something more advanced you'd have to make system calls (i.e. do it exactly the same was as in C).
Note that making file/dir is the only accurate way to know, since there can be more complex ACLs, quotas, and race conditions.