Entry points: userland process (continued)


ioctl
Most drivers have settings controlled by an I/O control
system call known as ioctl.

This takes a file descriptor, the request and an argment.
This is what things like ifconfig use to get/set interface parameters.

tht_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)

sysctl
The libc sysctl() wrapper around the __sysctl() system call
provides access to a name value list of values/settings.

This should normally be avoided by drivers for providing
settings/knobs but can be used to show state by interacting
with the sensors API in the kernel.

itp[p2]:~>sysctl hw
hw.machine=i386
hw.model=Intel(R) Pentium(R) M processor 1600MHz ("GenuineIntel" 686-class)
hw.ncpu=1
hw.physmem=267350016
hw.usermem=267345920
hw.pagesize=4096
hw.disknames=wd0
hw.diskcount=1
hw.vendor=IBM
hw.product=2672PEG
hw.version=ThinkPad X31