os: Implement open().

os/metadata.txt

@@ -1,5 +1,5 @@
 srctype = micropython-lib
 type = package
-version = 0.1.7
+version = 0.1.8
 author = Paul Sokolovsky
 depends = libc, errno, stat

os/os/__init__.py

@@ -21,6 +21,7 @@ rmdir_ = libc.func("i", "rmdir", "s")
 getcwd_ = libc.func("s", "getcwd", "si")
 opendir_ = libc.func("P", "opendir", "s")
 readdir_ = libc.func("P", "readdir", "P")
+open_ = libc.func("i", "open", "sii")
 read_ = libc.func("i", "read", "ipi")
 write_ = libc.func("i", "write", "iPi")
 close_ = libc.func("i", "close", "i")
@@ -37,6 +38,16 @@ W_OK = const(2)
 X_OK = const(1)
 F_OK = const(0)
 
+O_ACCMODE  = 0o0000003
+O_RDONLY   = 0o0000000
+O_WRONLY   = 0o0000001
+O_RDWR     = 0o0000002
+O_CREAT    = 0o0000100
+O_EXCL     = 0o0000200
+O_NOCTTY   = 0o0000400
+O_TRUNC    = 0o0001000
+O_APPEND   = 0o0002000
+O_NONBLOCK = 0o0004000
 
 error = OSError
 name = "posix"
@@ -132,6 +143,11 @@ def walk(top, topdown=True):
     if not topdown:
         yield top, dirs, files
 
+def open(n, flags, mode=0o777):
+    r = open_(n, flags, mode)
+    check_error(r)
+    return r
+
 def read(fd, n):
     buf = bytearray(n)
     r = read_(fd, buf, n)

os/setup.py

@@ -6,7 +6,7 @@ from setuptools import setup
 
 
 setup(name='micropython-os',
-      version='0.1.7',
+      version='0.1.8',
       description='os module for MicroPython',
       long_description="This is a module reimplemented specifically for MicroPython standard library,\nwith efficient and lean design in mind. Note that this module is likely work\nin progress and likely supports just a subset of CPython's corresponding\nmodule. Please help with the development if you are interested in this\nmodule.",
       url='https://github.com/micropython/micropython/issues/405',