This example gets the current code page and up to three other prepared code pages.

#define INCL_DOSNLS     /* National Language Support values */
#define INCL_DOSERRORS  /* DOS error values                 */
#include <os2.h>
#include <stdio.h>

int main(VOID) {
   ULONG  aulCpList[8]  = {0},                /* Code page list        */
          ulBufSize     = 8 * sizeof(ULONG),  /* Size of output list   */
          ulListSize    = 0,                  /* Size of list returned */
          indx          = 0;                  /* Loop index            */
   APIRET rc            = NO_ERROR;           /* Return code           */

   rc = DosQueryCp(ulBufSize,      /* Length of output code page list  */
                   aulCpList,      /* List of code pages               */
                   &ulListSize);   /* Length of list returned          */

   if (rc != NO_ERROR) {
      printf("DosQueryCp error: return code = %u\n",rc);
      return 1;
   } else {
      for (indx=0; indx < ulListSize/sizeof(ULONG); indx++)
         printf ("aulCpList[%u] = %u\n", indx, aulCpList[indx]);
   }

   return NO_ERROR;
}