HP-UX Reference (11i v2 03/08) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)

m
mesg(5) mesg(5)
(Tunable Kernel Parameters)
NAME
mesg - enable or disable System V IPC messages at boot time
DESCRIPTION
The
mesg tunable is obsolete. The System V IPC message subsystem is always enabled.
Overview
A System V message is just a sequence of bytes that can be passed between cooperating processes via a
message queue. Messages can be of any length up to a tunable maximum. Messages larger than 64 bytes
(not tunable) are stored in one or more contiguous "segments" of reserved kernel memory and are
managed through the message segment map. Messages equal to or smaller than 64 bytes are allocated
with the message header and therefore do not consume a segment. Each message is "typed" with an
application-specific number. Each message queue is referenced by a unique ID, and can contain multiple
individual messages.
The process receiving a message can get the "first" message (FIFO), the first of a specified type, the first of
a group of types, or wait for a specific type to appear.
AUTHOR
mesg was developed by AT&T.
SEE ALSO
ipcrm(1), ipcs(1), msgctl(2), msgget(2), msgrcv(2), msgsnd(2), msgmap(5), msgmax(5), msgmnb(5),
msgmni(5), msgseg(5), msgssz(5), msgtql(5).
Section 5−−176 Hewlett-Packard Company − 1 − HP-UX 11i Version 2: August 2003