查看“Ioctl”的源代码

== Linux ==
=== fields ===
IOC_NRBITS 8
IOC_TYPEBITS 8
IOC_SIZEBITS 14
IOC_DIRBITS 2

IOC_NRSHIFT 0
IOC_TYPESHIFT IOC_NRSHIFT+IOC_NRBITS = 8
IOC_SIZESHIFT IOC_TYPESHIFT + IOC_TYPESIZE = 16
IOC_DIRSHIFT IOC_SIZESHIFT + IOC_SIZEBITS = 30

DIR (2) | SIZE(14) | TYPE(8) | NR(8)

IOC(dir, type, nr, size)
dir << dirshift | type << typeshift | nr << nrshift | size << sizeshift

=== direction ===
IOC_NONE 0
IOC_WRITE 1
IOC_READ 2

=== example ===
0x8b01 type=8b(wireless) nr=01