Example

       /* 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