Getting a message

This example demonstrates how to use the MQGET call to remove a message from a queue.

This extract is taken from the Browse sample application (program CSQ4BCA1) supplied with IBM MQ for z/OS . For the names and locations of the sample applications on other platforms, see Sample procedural programs (platforms except z/OS ).

#include "cmqc.h"
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#define BUFFERLENGTH 80
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int main(int argc, char *argv[] )
   {
   /*                                                    */
   /*     Variables for MQ calls                         */
   /*                                                    */
   MQHCONN Hconn ;            /* Connection handle       */
   MQLONG  CompCode;          /* Completion code         */
   MQLONG  Reason;            /* Qualifying reason       */
   MQHOBJ  Hobj;              /* Object handle           */
   MQMD    MsgDesc  = { MQMD_DEFAULT };
                              /* Message descriptor      */
   MQLONG  DataLength ;       /* Length of the message   */
   MQCHAR  Buffer[BUFFERLENGTH+1];
                              /* Area for message data   */
   MQGMO   GetMsgOpts = { MQGMO_DEFAULT };
                              /* Options which control   */
                              /*  the MQGET call         */
   MQLONG  BufferLength = BUFFERLENGTH ;
                              /* Length of buffer        */
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   /*     No need to change the message descriptor       */
   /*     (MQMD) control block because initialization    */
   /*     default sets all the fields.                   */
   /*                                                    */
   /*     Initialize the get message options (MQGMO)     */
   /*     control block (the copy file initializes all   */
   /*     the other fields).                             */
   /*                                                    */
   GetMsgOpts.Options = MQGMO_NO_WAIT      +
                        MQGMO_BROWSE_FIRST +
                        MQGMO_ACCEPT_TRUNCATED_MSG;
   /*                                                    */
   /* Get the first message.                             */
   /*   Test for the output of the call is carried out   */
   /*   in the 'for' loop.                               */
   /*                                                    */
   MQGET(Hconn,
         Hobj,
         &MsgDesc,
         &GetMsgOpts,
         BufferLength,
         Buffer,
         &DataLength,
         &CompCode,
         &Reason);

   /*                                                    */
   /* Process the message and get the next message,      */
   /* until no messages remaining.                       */
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   /*     If the call fails for any other reason,        */
   /*     print an error message showing the completion  */
   /*     code and reason code.                          */
   /*                                                    */
   if ( (CompCode == MQCC_FAILED) &&
       (Reason   == MQRC_NO_MSG_AVAILABLE) )
      {
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      }
   else
      {
      sprintf(pBuff, MESSAGE_4_E,
              ERROR_IN_MQGET, CompCode, Reason);
      PrintLine(pBuff);
      RetCode = CSQ4_ERROR;
      }
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   } /* end of main */