MSG.H(3HEAD)MSG.H(3HEAD)NAME
msg.h, msg - message queue structures
SYNOPSIS
#include <sys/msg.h>
DESCRIPTION
The <sys/msg.h> header defines the following data types through type‐
def:
msgqnum_t
used for the number of messages in the message queue
msglen_t
used for the number of bytes allowed in the message queue
These types are unsigned integer types that are able to store values at
least as large as a type unsigned short.
The <sys/msg.h> header defines the following constant as a message
operation flag:
MSG_NOERROR
no error if big message
The msqid_ds structure contains the following members:
struct ipc_perm msg_perm Operation permission structure.
msgqnum_t msg_qnum Number of messages currently on
queue.
msglen_t msg_qbytes Maximum number of bytes allowed
on queue.
pid_t msg_lspid Process ID of last msgsnd(2).
pid_t msg_lrpid Process ID of last msgrcv(2).
time_t msg_stime Time of last msgsnd().
time_t msg_rtime Time of last msgrcv().
time_t msg_ctime Time of last change.
The pid_t, time_t, key_t, size_t, and ssize_t types are defined as
described in <sys/types.h>. See types(3HEAD).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOmsgctl(2), msgget(2), msgrcv(2), msgsnd(2), ipc.h(3HEAD),
types.h(3HEAD), attributes(5), standards(5)
Sep 10, 2004 MSG.H(3HEAD)