As explained in previous commits, the _peek_ call is advantageous because: - It is less bug-prone as we don't have to handle freeing the string. In all the cases I changed, I even spotted at least 2 cases where we were leaking a string (in file-mng, `temp_file_name` is never freed; and we were also leaking in an error case of gfig). - As a consequence of the previous point: simpler code with less lines. - In local file cases, the _peek_ variant does not even need to allocate an additional string. - In other case, if we query several times the path, it is allocated once and cached so it stays efficient. - When possible, working on the GFile rather than on a path string may be more robust. For instance I changed one g_unlink() into a g_file_delete(). Actually most reading/writing should be done with the GIO API when possible, but I didn't want to change too much code logics on this commit.