copying Markus Kuhn's ucs 2002-03-11 into trunk

svn path=/trunk/; revision=3976

1 files changed, 119 insertions, 0 deletions

diff --git a/ucs/langinfo.c b/ucs/langinfo.c
new file mode 100644
index 00000000..3d7d64d7
--- /dev/null
+++ b/ucs/langinfo.c
@@ -0,0 +1,119 @@
+/*
+ * This is a quick-and-dirty emulator of the nl_langinfo(CODESET)
+ * function defined in the Single Unix Specification for those systems
+ * (FreeBSD, etc.) that don't have one yet. It behaves as if it had
+ * been called after setlocale(LC_CTYPE, ""), that is it looks at
+ * the locale environment variables.
+ *
+ * http://www.opengroup.org/onlinepubs/7908799/xsh/langinfo.h.html
+ *
+ * Please extend it as needed and suggest improvements to the author.
+ * This emulator will hopefully become redundant soon as
+ * nl_langinfo(CODESET) becomes more widely implemented.
+ *
+ * Since the proposed Li18nux encoding name registry is still not mature,
+ * the output follows the MIME registry where possible:
+ *
+ *   http://www.iana.org/assignments/character-sets
+ *
+ * A possible autoconf test for the availability of nl_langinfo(CODESET)
+ * can be found in
+ *
+ *   http://www.cl.cam.ac.uk/~mgk25/unicode.html#activate
+ *
+ * Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11
+ * Permission to use, copy, modify, and distribute this software
+ * for any purpose and without fee is hereby granted. The author
+ * disclaims all warranties with regard to this software.
+ *
+ * Latest version:
+ *
+ *   http://www.cl.cam.ac.uk/~mgk25/ucs/langinfo.c
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "langinfo.h"
+
+#define C_CODESET "US-ASCII"     /* Return this as the encoding of the
+				  * C/POSIX locale. Could as well one day
+				  * become "UTF-8". */
+
+#define digit(x) ((x) >= '0' && (x) <= '9')
+
+static char buf[16];
+
+char *nl_langinfo(nl_item item)
+{
+  char *l, *p;
+  
+  if (item != CODESET)
+    return NULL;
+  
+  if (((l = getenv("LC_ALL"))   && *l) ||
+      ((l = getenv("LC_CTYPE")) && *l) ||
+      ((l = getenv("LANG"))     && *l)) {
+    /* check standardized locales */
+    if (!strcmp(l, "C") || !strcmp(l, "POSIX"))
+      return C_CODESET;
+    /* check for encoding name fragment */
+    if (strstr(l, "UTF") || strstr(l, "utf"))
+      return "UTF-8";
+    if ((p = strstr(l, "8859-"))) {
+      memcpy(buf, "ISO-8859-\0\0", 12);
+      p += 5;
+      if (digit(*p)) {
+	buf[9] = *p++;
+	if (digit(*p)) buf[10] = *p++;
+	return buf;
+      }
+    }
+    if (strstr(l, "KOI8-R")) return "KOI8-R";
+    if (strstr(l, "KOI8-U")) return "KOI8-U";
+    if (strstr(l, "620")) return "TIS-620";
+    if (strstr(l, "2312")) return "GB2312";
+    if (strstr(l, "HKSCS")) return "Big5HKSCS";   /* no MIME charset */
+    if (strstr(l, "Big5") || strstr(l, "BIG5")) return "Big5";
+    if (strstr(l, "GBK")) return "GBK";           /* no MIME charset */
+    if (strstr(l, "18030")) return "GB18030";     /* no MIME charset */
+    if (strstr(l, "Shift_JIS") || strstr(l, "SJIS")) return "Shift_JIS";
+    /* check for conclusive modifier */
+    if (strstr(l, "euro")) return "ISO-8859-15";
+    /* check for language (and perhaps country) codes */
+    if (strstr(l, "zh_TW")) return "Big5";
+    if (strstr(l, "zh_HK")) return "Big5HKSCS";   /* no MIME charset */
+    if (strstr(l, "zh")) return "GB2312";
+    if (strstr(l, "ja")) return "EUC-JP";
+    if (strstr(l, "ko")) return "EUC-KR";
+    if (strstr(l, "ru")) return "KOI8-R";
+    if (strstr(l, "uk")) return "KOI8-U";
+    if (strstr(l, "pl") || strstr(l, "hr") ||
+	strstr(l, "hu") || strstr(l, "cs") ||
+	strstr(l, "sk") || strstr(l, "sl")) return "ISO-8859-2";
+    if (strstr(l, "eo") || strstr(l, "mt")) return "ISO-8859-3";
+    if (strstr(l, "el")) return "ISO-8859-7";
+    if (strstr(l, "he")) return "ISO-8859-8";
+    if (strstr(l, "tr")) return "ISO-8859-9";
+    if (strstr(l, "th")) return "TIS-620";      /* or ISO-8859-11 */
+    if (strstr(l, "lt")) return "ISO-8859-13";
+    if (strstr(l, "cy")) return "ISO-8859-14";
+    if (strstr(l, "ro")) return "ISO-8859-2";   /* or ISO-8859-16 */
+    if (strstr(l, "am") || strstr(l, "vi")) return "UTF-8";
+    /* Send me further rules if you like, but don't forget that we are
+     * *only* interested in locale naming conventions on platforms
+     * that do not already provide an nl_langinfo(CODESET) implementation. */
+    return "ISO-8859-1"; /* should perhaps be "UTF-8" instead */
+  }
+  return C_CODESET;
+}
+
+/* For a demo, compile with "gcc -W -Wall -o langinfo -D TEST langinfo.c" */
+
+#ifdef TEST
+#include <stdio.h>
+int main()
+{
+  printf("%s\n", nl_langinfo(CODESET));
+  return 0;
+}
+#endif