WIP: utf8 support (yes, this is madness)

src/common/util/unicode.c

@@ -0,0 +1,140 @@
+/* vi: set ts=2:
+ * +-------------------+  Christian Schlittchen <corwin@amber.kn-bremen.de>
+ * |                   |  Enno Rehling <enno@eressea.de>
+ * | Eressea PBEM host |  Katja Zedel <katze@felidae.kn-bremen.de>
+ * | (c) 1998 - 2007   |  
+ * |                   |  This program may not be used, modified or distributed
+ * +-------------------+  without prior permission by the authors of Eressea.
+ *  
+ */
+
+#include <config.h>
+#include "unicode.h"
+
+#include <errno.h>
+
+/* Convert a UTF-8 encoded character to UCS-4. */
+int
+unicode_utf8_to_ucs4(wint_t *ucs4_character, const xmlChar *utf8_string, 
+                     size_t *length)
+{
+  xmlChar utf8_character = utf8_string[0];
+
+  /* Is the character in the ASCII range? If so, just copy it to the
+  output. */
+  if (utf8_character <= 0x7F)
+  {
+    *ucs4_character = utf8_character;
+    *length = 1;
+  }
+  else if ((utf8_character & 0xE0) == 0xC0)
+  {
+    /* A two-byte UTF-8 sequence. Make sure the other byte is good. */
+    if (utf8_string[1] != '\0' &&
+      (utf8_string[1] & 0xC0) != 0x80)
+    {
+      return EILSEQ;
+    }
+
+    *ucs4_character =
+      ((utf8_string[1] & 0x3F) << 0) +
+      ((utf8_character & 0x1F) << 6);
+    *length = 2;
+  }
+  else if ((utf8_character & 0xF0) == 0xE0)
+  {
+    /* A three-byte UTF-8 sequence. Make sure the other bytes are
+    good. */
+    if ((utf8_string[1] != '\0') &&
+      (utf8_string[1] & 0xC0) != 0x80 &&
+      (utf8_string[2] != '\0') &&
+      (utf8_string[2] & 0xC0) != 0x80)
+    {
+      return EILSEQ;
+    }
+
+    *ucs4_character = 
+      ((utf8_string[2] & 0x3F) << 0) +
+      ((utf8_string[1] & 0x3F) << 6) +
+      ((utf8_character & 0x0F) << 12);
+    *length = 3;
+  }
+  else if ((utf8_character & 0xF8) == 0xF0)
+  {
+    /* A four-byte UTF-8 sequence. Make sure the other bytes are
+    good. */
+    if ((utf8_string[1] != '\0') &&
+      (utf8_string[1] & 0xC0) != 0x80 &&
+      (utf8_string[2] != '\0') &&
+      (utf8_string[2] & 0xC0) != 0x80 &&
+      (utf8_string[3] != '\0') &&
+      (utf8_string[3] & 0xC0) != 0x80)
+    {
+      return EILSEQ;
+    }
+
+    *ucs4_character = 
+      ((utf8_string[3] & 0x3F) << 0) +
+      ((utf8_string[2] & 0x3F) << 6) +
+      ((utf8_string[1] & 0x3F) << 12) +
+      ((utf8_character & 0x07) << 18);
+    *length = 4;
+  }
+  else if ((utf8_character & 0xFC) == 0xF8)
+  {
+    /* A five-byte UTF-8 sequence. Make sure the other bytes are
+    good. */
+    if ((utf8_string[1] != '\0') &&
+      (utf8_string[1] & 0xC0) != 0x80 &&
+      (utf8_string[2] != '\0') &&
+      (utf8_string[2] & 0xC0) != 0x80 &&
+      (utf8_string[3] != '\0') &&
+      (utf8_string[3] & 0xC0) != 0x80 &&
+      (utf8_string[4] != '\0') &&
+      (utf8_string[4] & 0xC0) != 0x80)
+    {
+      return EILSEQ;
+    }
+
+    *ucs4_character = 
+      ((utf8_string[4] & 0x3F) << 0) +
+      ((utf8_string[3] & 0x3F) << 6) +
+      ((utf8_string[2] & 0x3F) << 12) +
+      ((utf8_string[1] & 0x3F) << 18) +
+      ((utf8_character & 0x03) << 24);
+    *length = 5;
+  }
+  else if ((utf8_character & 0xFE) == 0xFC)
+  {
+    /* A six-byte UTF-8 sequence. Make sure the other bytes are
+    good. */
+    if ((utf8_string[1] != '\0') &&
+      (utf8_string[1] & 0xC0) != 0x80 &&
+      (utf8_string[2] != '\0') &&
+      (utf8_string[2] & 0xC0) != 0x80 &&
+      (utf8_string[3] != '\0') &&
+      (utf8_string[3] & 0xC0) != 0x80 &&
+      (utf8_string[4] != '\0') &&
+      (utf8_string[4] & 0xC0) != 0x80 &&
+      (utf8_string[5] != '\0') &&
+      (utf8_string[5] & 0xC0) != 0x80)
+    {
+      return EILSEQ;
+    }
+
+    *ucs4_character = 
+      ((utf8_string[5] & 0x3F) << 0) +
+      ((utf8_string[4] & 0x3F) << 6) +
+      ((utf8_string[3] & 0x3F) << 12) +
+      ((utf8_string[2] & 0x3F) << 18) +
+      ((utf8_string[1] & 0x3F) << 24) +
+      ((utf8_character & 0x01) << 30);
+    *length = 6;
+  }
+  else
+  {
+    return EILSEQ;
+  }
+
+  return 0;
+}

src/common/util/unicode.h

@@ -0,0 +1,29 @@
+/* vi: set ts=2:
+ *
+ *	
+ *	Eressea PB(E)M host Copyright (C) 1998-2003
+ *      Christian Schlittchen (corwin@amber.kn-bremen.de)
+ *      Katja Zedel (katze@felidae.kn-bremen.de)
+ *      Henning Peters (faroul@beyond.kn-bremen.de)
+ *      Enno Rehling (enno@eressea-pbem.de)
+ *      Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
+ *
+ * This program may not be used, modified or distributed without
+ * prior permission by the authors of Eressea.
+ */
+
+#ifndef _UNICODE_H
+#define _UNICODE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <wchar.h>
+
+  extern int unicode_utf8_to_ucs4(wint_t *ucs4_character, const xmlChar *utf8_string, size_t *length);
+
+#ifdef __cplusplus
+}
+#endif
+#endif