#include <unixio.h>
        #include <file.h>
        #include <stdlib.h>

        main()
        {
            int file,
                stat;
            int flags;

            flags = O_RDWR; /*  Open for read and write, with user */
                            /*  with default file protection, with */
                            /*  max fixed record size of 2048, and */
                            /*  a block size of 2048 bytes.        */

 file = open("file.dat", flags, 0, "rfm=fix", "mrs=2048", "bls=2048");
            if (file == -1)
                perror("OPEN error"), exit(1);

            close(file);
        }