#
#	This is a simple wrapper module for Python that provides
#	a way to access FreeBSD's sysctl interface.  Example:
#
#	from sysctl import *
#	print "hw.ncpu = ", sysctl_int(sysctlnametomib("hw.ncpu"))
#
#	Copyright (c) 2010-2011 Oliver Fromme, Germany <olli@fromme.com>
#   All rights reserved.  2-clause BSD-style copyright and disclaimer
#   apply, plase see /usr/share/examples/etc/bsd-style-copyright on
#   FreeBSD machines, or ask the author for a copy.
#

debug = False

from os import strerror
from sys import stderr, exit

from ctypes import *
libc = CDLL("libc.so")
errno = c_int.in_dll(libc, "errno")

def check_fail (fail):
	if fail:
		exit (1)
	else:
		return None

def sysctlnametomib (name, fail = True):
	mibsize = len(name.split('.'))
	size = c_uint(mibsize)
	mib = (c_int * mibsize)()
	if libc.sysctlnametomib(name, byref(mib), byref(size)) != 0:
		print >> stderr, 'sysctlnametomib("%s"):' % name, strerror(errno.value)
		return check_fail(fail)
	if debug:
		print >> stderr, 'sysctlnametomib("%s") -->' % name, str(list(mib))
	return mib

def sysctl_numeric (type, mib, fail = True):
	size = c_uint(sizeof(type))
	value = type(0)
	if libc.sysctl(byref(mib), len(mib), byref(value), byref(size), None, 0) != 0:
		print >> stderr, 'sysctl(%s):' % str(list(mib)), strerror(errno.value)
		return check_fail(fail)
	if debug:
		print >> stderr, 'sysctl(%s) -->' % str(list(mib)), repr(value.value)
	return value.value

def sysctl_int (mib, fail = True):
	return sysctl_numeric(c_int, mib, fail)

def sysctl_uint (mib, fail = True):
	return sysctl_numeric(c_uint, mib, fail)

def sysctl_long (mib, fail = True):
	return sysctl_numeric(c_long, mib, fail)

def sysctl_ulong (mib, fail = True):
	return sysctl_numeric(c_ulong, mib, fail)

def sysctl_numericarray (type, mib, count = None, fail = True):
	if count is None:
		size = c_uint(0)
		if libc.sysctl(byref(mib), len(mib), None, byref(size), None, 0) != 0:
			print >> stderr, 'sysctl(%s):' % str(list(mib)), strerror(errno.value)
			return check_fail(fail)
		if debug:
			print >> stderr, 'sysctl(%s) --> size' % str(list(mib)), size.value
		count = size.value / sizeof(type)
	else:
		size = c_uint(count * sizeof(type))
	value = (type * count)()
	if libc.sysctl(byref(mib), len(mib), byref(value), byref(size), None, 0) != 0:
		print >> stderr, 'sysctl(%s):' % str(list(mib)), strerror(errno.value)
		return check_fail(fail)
	if debug:
		print >> stderr, 'sysctl(%s) -->' % str(list(mib)), repr(list(value))
	return list(value)

def sysctl_intarray (mib, count = None, fail = True):
	return sysctl_numericarray(c_int, mib, count, fail)

def sysctl_uintarray (mib, count = None, fail = True):
	return sysctl_numericarray(c_uint, mib, count, fail)

def sysctl_longarray (mib, count = None, fail = True):
	return sysctl_numericarray(c_long, mib, count, fail)

def sysctl_ulongarray (mib, count = None, fail = True):
	return sysctl_numericarray(c_ulong, mib, count, fail)

def sysctl_str (mib, fail = True):
	size = c_uint(0)
	if libc.sysctl(byref(mib), len(mib), None, byref(size), None, 0) != 0:
		print >> stderr, 'sysctl(%s):' % str(list(mib)), strerror(errno.value)
		return check_fail(fail)
	if debug:
		print >> stderr, 'sysctl(%s) --> size' % str(list(mib)), size.value
	value = create_string_buffer(size.value)
	if libc.sysctl(byref(mib), len(mib), byref(value), byref(size), None, 0) != 0:
		print >> stderr, 'sysctl(%s):' % str(list(mib)), strerror(errno.value)
		return check_fail(fail)
	if debug:
		print >> stderr, 'sysctl(%s) -->' % str(list(mib)), repr(value.value)
	return value.value

#--