This example creates a pipe and duplicates its read/write handles.

#define INCL_DOSQUEUES        /* Queue values */
#define INCL_DOSERRORS        /* DOS Error values */
#include <os2.h>
#include <stdio.h>

int main(VOID) {

HFILE    ReadHandle     = NULLHANDLE; /* Read handle of pipe */
HFILE    WriteHandle    = NULLHANDLE; /* Write handle of pipe */
HFILE    NewReadHandle  = (HFILE) -1; /* Duplicate read handle */
HFILE    NewWriteHandle = (HFILE) 10; /* Duplicate write handle */
ULONG    PipeSize       = 42;         /* Size of pipe */
APIRET   rc             = NO_ERROR;   /* API return code */

rc = DosCreatePipe ( &ReadHandle, &WriteHandle, PipeSize );
if (rc != NO_ERROR) {
   printf("DosCreatePipe error: return code = %u\n", rc);
   return 1;
}
      /* Duplicate Read Handle of Pipe - use next available handle */

rc = DosDupHandle ( ReadHandle, &NewReadHandle );
if (rc != NO_ERROR) {
   printf("DosDupHandle error: return code = %u\n", rc);
   return 1;
}
      /* Duplicate Write Handle of Pipe - use handle 10 */

rc = DosDupHandle ( ReadHandle, &NewWriteHandle );
if (rc != NO_ERROR) {
   printf("DosDupHandle error: return code = %u\n", rc);
   return 1;
}

printf("Handles are: Read:%u  Write:%u  NewRead:%u  NewWrite:%u\n",
            ReadHandle, WriteHandle, NewReadHandle, NewWriteHandle);

return NO_ERROR;
}