cfunction
src/core/os.c on line 2002, column 1
(os/perm-int bytes)
Parse a 9-character permission string and return an integer that
can be used by chmod.
(os/perm-int "rw-r--r--") # => 420
(os/perm-int "rwxr-xr-x") # => 493
# note:
8r644 # => 420
8r755 # => 493