PKON(2) System Calls Manual PKON(2)
pkon, pkoff - establish packet protocol
Pkon establishes packet protocol (see pk(4)) on the open character spe-
cial file whose file descriptor is fd. Size is a desired packet size,
a power of 2 in the range 32<=size<=4096. The size is negotiated with
a remote packet driver, and a possibly smaller actual packet size is
An asynchronous line used for packet communication should be in raw
mode; see tty(4).
Pkoff turns off the packet driver on the channel whose file descriptor
pk(4), pkopen(3), tty(4), signal(2)
Pkon returns -1 if fd does not describe an open file, or if packet com-
munication cannot be established.
Pkoff returns -1 for an unknown file descriptor.
Writing on a packet driver link that has been shut down by close or
pkoff at the other end raises signal SIGPIPE in the writing process.