int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
The mq_getattr() function shall obtain status information and attributes of the message queue and the open message queue description associated with the message queue descriptor.
The mqdes argument specifies a message queue descriptor.
The results shall be returned in the mq_attr structure referenced by the mqstat argument.
Upon return, the following members shall have the values associated with the open message queue description as set when the message queue was opened and as modified by subsequent mq_setattr() calls: mq_flags.
The following attributes of the message queue shall be returned as set at message queue creation: mq_maxmsg, mq_msgsize.
Upon return, the following members within the mq_attr structure referenced by the mqstat argument shall be set to the current state of the message queue:
Upon successful completion, the mq_getattr() function shall return zero. Otherwise, the function shall return -1 and set errno to indicate the error.
The mq_getattr() function shall fail if:
The following sections are informative.
mq_open() , mq_send() , mq_setattr() , mq_timedsend() , msgctl() , msgget() , msgrcv() , msgsnd() , the Base Definitions volume of IEEE Std 1003.1-2001, <mqueue.h>