Difference between revisions of "MQOPEN()"

From Recital Documentation Wiki
Jump to: navigation, search
 
 
(10 intermediate revisions by one user not shown)
Line 1: Line 1:
{{YLM to do}}
 
 
==Purpose==
 
==Purpose==
 
Open a pointer to a message queue
 
Open a pointer to a message queue
Line 9: Line 8:
  
 
==See Also==
 
==See Also==
[[MQCLOSE()]], [[MQCURMSGS()]], [[MQCREATE()]], [[MQRECEIVE()]], [[MQSEND()]]
+
[[MQCLOSE()]], [[MQCREATE()]], [[MQCURMSGS()]], [[MQRECEIVE()]], [[MQSEND()]], [[MQUNLINK()]], [[XML_DECODE()]], [[XML_ENCODE()]], [[XML_GATHER()]], [[XML_SCATTER()]]
  
  
Line 19: Line 18:
 
!<expN>||Access Mode
 
!<expN>||Access Mode
 
|-
 
|-
|||If not specified, read-only
+
|Unspecified||Read only access
 
|-
 
|-
|0||Read-only
+
|0||Read only access
 
|-
 
|-
|1||Write only.  Existing contents are deleted.
+
|1||Write only access
 
|-
 
|-
|2||Append.  Text may be added to the end of the existing contents.
+
|2||Read/Write access
 
|-
 
|-
 
|}
 
|}
  
  
The MQCLOSE() function is used to close a queue which has been opened with 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.
  
  
Line 37: Line 38:
 
mqdes=mqopen("/myqueue")
 
mqdes=mqopen("/myqueue")
 
if (mqdes < 0)
 
if (mqdes < 0)
  messagebox(strerror()+",errno="+alltrim(str(error())))
+
    messagebox(strerror()+",errno="+alltrim(str(error())))
  return
+
    return
 
endif
 
endif
 
do while (mqcurmsgs(mqdes) > 0)
 
do while (mqcurmsgs(mqdes) > 0)
  mstr=mqreceive(mqdes)
+
    mstr=mqreceive(mqdes)
  if (empty(mstr))
+
    if (empty(mstr))
      messagebox(strerror()+",errno="+alltrim(str(error())))
+
        messagebox(strerror()+",errno="+alltrim(str(error())))
      return
+
        return
  endif
+
    endif
  messagebox(mstr)
+
    messagebox(mstr)
end do
+
enddo
 
mqclose(mqdes)
 
mqclose(mqdes)
 
</code>
 
</code>

Latest revision as of 10:10, 5 July 2011

Purpose

Open a pointer to a message queue


Syntax

MQOPEN(<expC> [,<expN>])


See Also

MQCLOSE(), MQCREATE(), MQCURMSGS(), MQRECEIVE(), MQSEND(), MQUNLINK(), XML_DECODE(), XML_ENCODE(), XML_GATHER(), XML_SCATTER()


Description

The MQOPEN() function opens an existing message queue. It returns a numeric pointer when the queue is opened successfully, or a -1 if unsuccessful. The <expC> is the name of the queue to open. Since the pointer is required to identify an open queue to other messaging functions, always assign the return value to a memory variable. The optional <expN> determines the queue access mode:


<expN> Access Mode
Unspecified Read only access
0 Read only access
1 Write only access
2 Read/Write access


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

mqdes=mqopen("/myqueue")
if (mqdes < 0)
    messagebox(strerror()+",errno="+alltrim(str(error())))
    return
endif
do while (mqcurmsgs(mqdes) > 0)
    mstr=mqreceive(mqdes)
    if (empty(mstr))
        messagebox(strerror()+",errno="+alltrim(str(error())))
        return
    endif
    messagebox(mstr)
enddo
mqclose(mqdes)


Products

Recital, Recital Server