MQI calls

Use this information to learn about calls in the Message Queue Interface (MQI).

The calls in the MQI can be grouped as follows:

MQCONN, MQCONNX, and MQDISC: Use these calls to connect a program to (with or without options), and disconnect a program from, a queue manager. If you write CICS® programs for z/OS®, you do not need to use these calls. However, you are recommended to use them if you want to port your application to other platforms.
MQOPEN and MQCLOSE: Use these calls to open and close an object, such as a queue.
MQPUT and MQPUT1: Use these calls to put a message on a queue.
MQGET: Use this call to browse messages on a queue, or to remove messages from a queue.
MQSUB, MQSUBRQ: Use these calls to register a subscription to a topic, and to request publications matching the subscription.
MQINQ: Use this call to inquire about the attributes of an object.
MQSET: Use this call to set some of the attributes of a queue. You cannot set the attributes of other types of object.
MQBEGIN, MQCMIT, and MQBACK: Use these calls when IBM® MQ is the coordinator of a unit of work. MQBEGIN starts the unit of work. MQCMIT and MQBACK end the unit of work, either committing or rolling back the updates made during the unit of work. IBM i commitment controller is used to coordinate global units of work on IBM MQ for IBM i. Native start commitment control, commit, and rollback commands are used.
MQCRTMH, MQBUFMH, MQMHBUF, MQDLTMH: Use these calls to create a message handle, to convert a message handle to a buffer or a buffer to a message handle, and to delete a message handle.
MQSETMP, MQINQMP, MQDLTMP: Use these calls to set a message property on a message handle, inquire on a message property, and delete a property from a message handle.
MQCB, MQCB_FUNCTION, MQCTL: Use these calls to register and control a callback function.
MQSTAT: Use this call to retrieve status information about previous asynchronous put operations.

See Call descriptions for a description of the MQI calls.