/* This program verifies that two transformed strings when      */
        /* passed through strxfrm and then compared, provide the same   */
        /* result as if passed through strcoll without any              */
        /* transformation.

        #include <string.h>
        #include <stdio.h>
        #include <stdlib.h>
        #include <locale.h>

        #define  BUFF_SIZE  256

        main()
        {
           char string1[BUFF_SIZE];
           char string2[BUFF_SIZE];
           int errno;
           int coll_result;
           int strcmp_result;
           size_t strxfrm_result1;
           size_t strxfrm_result2;

           /* setlocale to French locale */

           if (setlocale(LC_ALL, "fr_FR.ISO8859-1") == NULL) {
               perror("setlocale");
               exit(EXIT_FAILURE);
           }

           /* collate string 1 and string 2 and store the result */

           errno = 0;
           coll_result = strcoll("<a`>bcd", "abcz");
           if (errno) {
               perror("strcoll");
               exit(EXIT_FAILURE);
           }

           else {
               /* Transform the strings (using strxfrm) into string1   */
               /* and string2                                          */

               strxfrm_result1 = strxfrm(string1, "<a`>bcd", BUFF_SIZE);

               if (strxfrm_result1 == ((size_t) - 1)) {
                   perror("strxfrm");
                   exit(EXIT_FAILURE);
               }

               else if (strxfrm_result1 > BUFF_SIZE) {
                   perror("\n** String is too long **\n");
                   exit(EXIT_FAILURE);
               }

               else {
                   strxfrm_result2 = strxfrm(string2, "abcz", BUFF_SIZE);
                   if (strxfrm_result2 == ((size_t) - 1)) {
                       perror("strxfrm");
                       exit(EXIT_FAILURE);
                   }

                   else if (strxfrm_result2 > BUFF_SIZE) {
                       perror("\n** String is too long **\n");
                       exit(EXIT_FAILURE);
                   }

                   /* Compare the two transformed strings and verify   */
                   /* that the result is the same as the result from   */
                   /* strcoll on the original strings                  */
                   else {
                       strcmp_result = strcmp(string1, string2);
                       if (strcmp_result == 0 && (coll_result == 0)) {
                           printf("\nReturn value from strcoll() and "
                             "return value from strcmp() are both zero.");
                          printf("\nThe program was successful\n\n");
                       }

                       else if ((strcmp_result < 0) && (coll_result < 0)) {
                           printf("\nReturn value from strcoll() and "
                        "return value from strcmp() are less than zero.");
                           printf("\nThe program successful\n\n");
                       }

                       else if ((strcmp_result > 0) && (coll_result > 0)) {
                           printf("\nReturn value from strcoll() and "
                     "return value from strcmp() are greater than zero.");
                           printf("\nThe program was successful\n\n");
                       }

                       else {
                       printf("** Error **\n");
                       printf("\nReturn values are not of the same type");
                       }
                    }
                }
           }
        }

    Running the example program produces the following result:

    Return value from strcoll() and return value
                   from strcmp() are less than zero.
    The program was successful