This example updates the paths to be searched before and after the system LIBPATH, when locating a DLL.

 #define INCL_DOSMISC
 #define INCL_DOSERRORS
 #include <os2.h>
 #include <stdio.h>

 int main(VOID) {

 UCHAR   uchBeginLIBPATH[512] = "";       /* Begin LIBPATH value returned */
 UCHAR   uchEndLIBPATH[512]   = "";       /* End LIBPATH value returned   */
 APIRET  rc                   = NO_ERROR;    /* Return code               */

    rc = DosSetExtLIBPATH("C:\\TOOL_X\\VERS_20\\DLL",
                          BEGIN_LIBPATH);    /* Add to beginning LIBPATH */
    if (rc != NO_ERROR) {
        printf("DosSetExtLIBPATH error: return code = %u\n", rc);
        return 1;
    }

    rc = DosSetExtLIBPATH("C:\\TOOL_X\\VERS_10\\DLL",
                          END_LIBPATH);      /* Add to ending LIBPATH   */
    if (rc != NO_ERROR) {
        printf("DosSetExtLIBPATH error: return code = %u\n", rc);
        return 1;
    }

    rc = DosQueryExtLIBPATH(uchBeginLIBPATH,
                            BEGIN_LIBPATH);   /* Query the BeginLIBPATH */
    if (rc != NO_ERROR) {
        printf("DosQueryExtLIBPATH error: return code = %u\n", rc);
        return 1;
    }

    rc = DosQueryExtLIBPATH(uchEndLIBPATH,
                            END_LIBPATH);     /* Query the EndLIBPATH   */
    if (rc != NO_ERROR) {
        printf("DosQueryExtLIBPATH error: return code = %u\n", rc);
        return 1;
    }

    printf(" BeginLIBPATH = %s\n", uchBeginLIBPATH);
    printf("   EndLIBPATH = %s\n", uchEndLIBPATH);

  return NO_ERROR;
}