Metadata-Version: 1.1
Name: ioctl-opt
Version: 1.2.2
Summary: Functions to compute fnctl.ioctl's opt argument
Home-page: http://github.com/vpelletier/python-ioctl-opt
Author: Vincent Pelletier
Author-email: plr.vincent@gmail.com
License: GPL 2+
Description-Content-Type: UNKNOWN
Description: Pythonified linux ``asm-generic/ioctl.h`` .
        
        So you can replicate driver's code computing ``fcntl.ioctl``'s ``opt`` argument.
        
        For example, starting from the following IOCTL declaration (taken from ``input.h``):
        
        .. code:: C
        
          #include <sys/ioctl.h>
          #define EVIOCGNAME(len) _IOC(_IOC_READ, 'E', 0x06, len) /* get device name */
          
        you could write the following:
        
        .. code:: python
        
          from ioctl_opt import IOC, IOC_READ
          EVIOCGNAME = lambda length: IOC(IOC_READ, ord('E'), 0x06, length)
        
        The differences are minimal, and all come from python language or coding style:
        
        - macros/constants to use from ``ioctl_opt`` for not start with an underscore
        - defined macro becomes a callable (here a lambda, could be function)
        - ``IOC``'s ``nr`` argument has to be an integer, so C's single-quote char becomes an ``ord`` call
        - avoid shadowing built-in ``len`` function
        
        You may want to then write a pythonic function to conveniently access that ioctl:
        
        .. code:: python
        
          import ctypes
          import fcntl
          
          def getDeviceName(fd, length=1024):
              name = (ctypes.c_char * length)()
              actual_length = fcntl.ioctl(fd, EVIOCGNAME(length), name, True)
              if actual_length < 0:
                  raise OSError(-actual_length)
              if name[actual_length - 1] == b'\x00':
                  actual_length -= 1
              return name[:actual_length]
        
        More advanced example defining hidraw ioctls, requiring structures (for more on how structures are defined, check python's ctype documentation for your python version):
        
        .. code:: python
        
          import ctypes
          from ioctl_opt import IOR, IOC, IOC_READ, IOC_WRITE
        
          # hid.h
          HID_MAX_DESCRIPTOR_SIZE = 4096
        
          # hidraw.h
          class hidraw_report_descriptor(ctypes.Structure):
              _fields_ = [
                  ('size', ctypes.c_uint),
                  ('value', ctypes.c_ubyte * HID_MAX_DESCRIPTOR_SIZE),
              ]
        
          class hidraw_devinfo(ctypes.Structure):
              _fields_ = [
                  ('bustype', ctypes.c_uint),
                  ('vendor', ctypes.c_short),
                  ('product', ctypes.c_short),
              ]
        
          HIDIOCGRDESCSIZE = IOR(ord('H'), 0x01, ctypes.c_int)
          HIDIOCGRDESC = IOR(ord('H'), 0x02, hidraw_report_descriptor)
          HIDIOCGRAWINFO = IOR(ord('H'), 0x03, hidraw_devinfo)
          HIDIOCGRAWNAME = lambda length: IOC(IOC_READ, ord('H'), 0x04, length)
          HIDIOCGRAWPHYS = lambda length: IOC(IOC_READ, ord('H'), 0x05, length)
          HIDIOCSFEATURE = lambda length: IOC(IOC_WRITE|IOC_READ, ord('H'), 0x06, length)
          HIDIOCGFEATURE = lambda length: IOC(IOC_WRITE|IOC_READ, ord('H'), 0x07, length)
        
Keywords: ioctl
Platform: UNKNOWN
Classifier: Intended Audience :: Information Technology
Classifier: License :: OSI Approved :: GNU General Public License (GPL)
Classifier: Operating System :: POSIX :: Linux
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
