Difference between revisions of "MQRECEIVE()"

Revision as of 11:29, 19 November 2009

Purpose

Get a message from an open message queue

Syntax

MQRECEIVE(<expN>)

See Also

MQCLOSE(), MQCREATE(), MQCURMSGS(), MQOPEN(), MQSEND()

Description

The MQRECEIVE() function gets a message from an open message queue. It returns the message as a character string. If an error occurs and it is unable to get the message, it returns an empty string and the ERRNO() function can be checked to determine the error. The <expN> is the pointer to a queue opened with MQCREATE() or MQOPEN().

The MQCLOSE() function is used to close a queue which has been opened with MQOPEN() or MQCREATE().

For more examples of handling message queues, please see the examples/mqueue programs in the software distribution.

Example

// Open up the queue for reading
mqdes=mqopen("/myqueue")
if (mqdes < 0)
    messagebox(strerror()+",errno="+alltrim(str(error())))
    return
endif
// do while there are messages
do while (mqcurmsgs(mqdes) > 0)
    // Get each message
    mstr=mqreceive(mqdes)
    if (empty(mstr))
        messagebox(strerror()+",errno="+alltrim(str(error())))
        return
    endif
    messagebox(mstr)
enddo
mqclose(mqdes)

Products

Recital, Recital Server