Do not solve access failures by making everything world-writable

Describe the exact operation

The operating system checks different privileges for reading a file, entering a directory, creating a new entry and executing a program. Begin with the failing filename, process identity and action; ls -l on the final file is incomplete if a parent directory lacks search permission. ACLs and mount flags can further constrain access even if ordinary mode bits appear correct.

id
namei -l ./example/path 2>/dev/null || true
ls -ld . ./example 2>/dev/null || true
findmnt -T . -o TARGET,FSTYPE,OPTIONS 2>/dev/null || true

Separate authority from symptoms

A script can be readable and still fail direct execution on a noexec mount. A directory may permit listing but not traversal, depending on modes and ACLs. An executable invoked by an interpreter (for instance python script.py) follows different checks from ./script.py. getfacl is useful if installed, but absence of that utility is not evidence no ACL exists.

Controlled fixture

In a disposable directory belonging to you, create one regular text file and show read access. Then change only its permissions and compare stat and the result under the same user. Restore the original mode before finishing. Avoid using recursive chmod -R 777, global ownership changes or administrator execution as shortcuts.

End with least privilege

The correct fix might be moving project output to a user-writable directory, granting a specific group read permission, or correcting a directory's ownership via the authorized administrator. Capture before/after results for the same operation and explain why broader permissions would be unnecessary.

Directory permissions change the meaning of the operation

Reading a file checks its read permission plus traversal on parent directories. Creating or deleting a directory entry requires appropriate rights on the parent directory, not simply write permission on the file. Deleting a writable file and editing its bytes are different operations; sticky directories add further restrictions. ACL masks can reduce the effective rights of named users or groups, so inspect the effective result rather than adding mode bits at random.

Reproducible permission experiment

In a new temporary directory, create note.txt, record its original mode, remove only its owner-read bit and attempt the same read under the same account. Restore the mode in a finally/cleanup path. If the test runs as root or with a relevant capability, it may still succeed: that is an account-context result, not proof that mode bits are irrelevant. Repeat as an ordinary account before drawing conclusions.

An interpreter reading python note.py is different from executing ./note.py; the first still needs readable source and an executable interpreter. Neither pattern gives Android apps access outside their sandbox. On shared Android storage, place the project in Termux-private storage when it needs Unix execution or symlink behavior.