This example demonstrates how the library is used to convert ASCII compatible names to internationalized domain names.
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <locale.h> /* setlocale() */ #include <stringprep.h> /* stringprep_locale_charset() */ #include <idna.h> /* idna_to_unicode_lzlz() */ /* * Compiling using libtool and pkg-config is recommended: * * $ libtool cc -o example4 example4.c `pkg-config --cflags --libs libidn` * $ ./example4 * Input domain encoded as `ISO-8859-1': www.xn--rksmrgsa-0zap8p.example * Read string (length 33): 77 77 77 2e 78 6e 2d 2d 72 6b 73 6d 72 67 73 61 2d 30 7a 61 70 38 70 2e 65 78 61 6d 70 6c 65 * ACE label (length 23): 'www.räksmörgåsa.example' * 77 77 77 2e 72 e4 6b 73 6d f6 72 67 e5 73 61 2e 65 78 61 6d 70 6c 65 * $ * */ int main (void) { char buf[BUFSIZ]; char *p; int rc; size_t i; setlocale (LC_ALL, ""); printf ("Input domain encoded as `%s': ", stringprep_locale_charset ()); fflush (stdout); if (!fgets (buf, BUFSIZ, stdin)) perror ("fgets"); buf[strlen (buf) - 1] = '\0'; printf ("Read string (length %ld): ", (long int) strlen (buf)); for (i = 0; i < strlen (buf); i++) printf ("%02x ", (unsigned) buf[i] & 0xFF); printf ("\n"); rc = idna_to_unicode_lzlz (buf, &p, 0); if (rc != IDNA_SUCCESS) { printf ("ToUnicode() failed (%d): %s\n", rc, idna_strerror (rc)); return EXIT_FAILURE; } printf ("ACE label (length %ld): '%s'\n", (long int) strlen (p), p); for (i = 0; i < strlen (p); i++) printf ("%02x ", (unsigned) p[i] & 0xFF); printf ("\n"); free (p); return 0; }