Adding libc module for purpose of 2.0.0 support.

glymur/lib/__init__.py

@@ -1,3 +1,4 @@
 """This package organizes individual libraries employed by glymur."""
 from . import openjp2 as _openjp2
 from . import openjpeg as _openjpeg
+from . import c

glymur/lib/c.py

@@ -0,0 +1,45 @@
+"""
+Wraps fopen and fclose functions in libc.
+"""
+
+import ctypes
+import ctypes.util
+
+libc_path = ctypes.util.find_library('c')
+C_LIB = ctypes.CDLL(libc_path)
+
+def fopen(filename, mode):
+    """Opens the file with the specified mode.
+
+    Parameters
+    ----------
+    filename : str
+        Path to filename.
+    mode : str
+        Specifies how the file is to be opened.
+
+    Returns
+    -------
+    fptr : ctypes.c_void_p
+        File pointer.
+    """
+    C_LIB.fopen.restype = ctypes.c_void_p
+    C_LIB.fopen.argtypes = [ctypes.c_char_p, ctypes.c_char_p]
+    fptr = C_LIB.fopen(ctypes.c_char_p(filename.encode()),
+                       ctypes.c_char_p(mode.encode()))
+    return fptr
+
+def fclose(fptr):
+    """Closes a file stream.
+
+    Parameters
+    ----------
+    fptr : ctypes.c_void_p
+        File pointer.
+    """
+    C_LIB.fclose.argtypes = [ctypes.c_void_p]
+    C_LIB.fclose.restype = ctypes.c_int32
+    status = C_LIB.fclose(fptr)
+    if status != 0:
+        raise IOError("Unable to close file.")
+