This example shows how to create, write, querie, and close a queue.
#define INCL_DOSQUEUES /* DOS Queue values */ #define INCL_DOSERRORS /* DOS Error values */ #include <os2.h> #include <stdio.h> #include <string.h> #define QUE_NAME "\\QUEUES\\PANDAWRITE\\LOCALQUEUE" int main(VOID) { HQUEUE QueueHandle = NULLHANDLE; /* Queue handle */ CHAR *DataBuffer = ""; /* Data to write to queue */ ULONG ulNumElems = 0L; /* Number of elements on queue */ APIRET rc = NO_ERROR; /* Return code */ rc = DosCreateQueue(&QueueHandle, /* Queue handle */ QUE_LIFO | /* Last In, First Out ordering */ QUE_CONVERT_ADDRESS, /* Do 16-bit to 32-bit conversion */ QUE_NAME); /* Name of the queue */ if (rc!= NO_ERROR) { printf ("DosCreateQueue error: return code = %u\n", rc); return 1; } DataBuffer = "Element 1 of 2"; rc = DosWriteQueue (QueueHandle, 100L, strlen(DataBuffer), (PVOID)DataBuffer, 0L); if (rc!= NO_ERROR) { printf ("DosWriteQueue error: return code = %u\n", rc); return 1; } rc = DosQueryQueue (QueueHandle, &ulNumElems); if (rc != NO_ERROR) { printf ("DosQueryQueue error: return code = %u\n", rc); return 1; } else { printf ("DosQueryQueue: %u elements\n", ulNumElems); } DataBuffer = "Element 2 of 2"; rc = DosWriteQueue (QueueHandle, 200L, strlen(DataBuffer), (PVOID)DataBuffer, 0L); if (rc!= NO_ERROR) { printf ("DosWriteQueue error: return code = %u\n", rc); return 1; } rc = DosQueryQueue (QueueHandle, &ulNumElems); if (rc != NO_ERROR) { printf ("DosQueryQueue error: return code = %u\n", rc); return 1; } else { printf ("DosQueryQueue: %u elements\n", ulNumElems); } rc = DosPurgeQueue (QueueHandle); if (rc != NO_ERROR) { printf ("DosPurgeQueue error: return code = %u\n", rc); return 1; } rc = DosQueryQueue (QueueHandle, &ulNumElems); if (rc != NO_ERROR) { printf ("DosQueryQueue error: return code = %u\n", rc); return 1; } else { printf ("DosQueryQueue: %u elements\n", ulNumElems); } rc = DosCloseQueue(QueueHandle); /* Close the queue */ if (rc!= NO_ERROR) { printf ("DosCloseQueue error: return code = %u\n", rc); return 1; } return NO_ERROR; }