Use this tag if your issue is with permissions in the file system (files & directories). For app permissions, use the 'permissions' tag instead.

What are file permissions?

Android uses Linux at its core, and Unix/Linux use a special permission system on files:

  • each file has an owner (single user), and a group (user group) it is owned by
  • permissions are granted to the owner, the group, and "others" (neither being the user nor belonging to the group)
  • permissions basically consist of being allowed to read, write, and execute a file (in case of a directory, "execute" means to change into it)

Thus a permission-set basically consists of three groups, prefixed by a "type":

  • drwxrwxrwx would be a directory with full permissions to everybody
  • -rwx------ would be a very private file (only the owner has permissions to do everything with it)
  • -rw-rw--- looks like a document/data file read- and writable by the owner and the group.

Related tags:

Further readings