This example creates a FIFO queue named "SPECIAL.QUE". It also opens it, writes to it, reads from it, and finally closes it.
#define INCL_DOSQUEUES /* DOS Queue values */ #define INCL_DOSPROCESS /* DOS thread and process values */ #define INCL_DOSERRORS /* DOS error values */ #include <os2.h> #include <stdio.h> #include <string.h> int main(VOID) { PSZ szQueueName = "\\QUEUES\\SPECIAL.QUE"; HQUEUE hqSpecialQue = NULLHANDLE; /* Queue handle */ PSZ DataBuffer = ""; /* Data buffer for queue data */ REQUESTDATA Request = {0}; /* Reques */ PID pidOwner = 0; ULONG ulDataLen = 0; /* Length of data returned */ BYTE ElemPrty = 0; /* Priority of element (returned) */ APIRET rc = NO_ERROR; /* Return code */ rc = DosCreateQueue(&hqSpecialQue, /* Queue handle */ QUE_FIFO | /* First-In First-Out order */ QUE_CONVERT_ADDRESS, /* Convert 16-bit addresses to 32 */ szQueueName); /* Name of the queue to create */ if (rc!= NO_ERROR) { printf ("DosCreateQueue error: return code = %u\n", rc); return 1; } rc = DosOpenQueue (&pidOwner, /* PID of queue owner */ &hqSpecialQue, /* Handle for created queue */ szQueueName); /* Name of the queue to open */ if (rc!= NO_ERROR) { printf ("DosOpenQueue error: return code = %u\n", rc); return 1; } DataBuffer = "To be, or not to be. That is the question..."; rc = DosWriteQueue (hqSpecialQue, /* Queue to write to */ 12345L, /* Request data */ strlen(DataBuffer), /* Length of data to write */ DataBuffer, /* Pointer to data */ 0L); /* Priority (not applicable here) */ if (rc!= NO_ERROR) { printf ("DosWriteQueue error: return code = %u\n", rc); return 1; } DataBuffer = ""; /* Clear the DataBuffer */ Request.pid = pidOwner; /* process ID for the DosReadQueue */ rc = DosReadQueue (hqSpecialQue, /* Queue to read from */ &Request, /* Request data from write */ &ulDataLen, /* Length of data returned */ (PVOID) &DataBuffer, /* The data */ 0L, /* Remove first element */ DCWW_WAIT, /* Wait for available data */ &ElemPrty, /* Priority of data (returned) */ 0L); /* Semaphore to use when not waiting */ if (rc!= NO_ERROR) { printf ("DosReadQueue error: return code = %u\n", rc); return 1; } else { printf ("DosReadQueue returns: '%s'\n", DataBuffer); printf (" (Request data = %u)\n", Request.ulData); } rc = DosCloseQueue(hqSpecialQue); /* Close the queue */ if (rc!= NO_ERROR) { printf ("DosCloseQueue error: return code = %u\n", rc); return 1; } return NO_ERROR; }