1 files changed, 74 insertions, 0 deletions
diff --git a/src/lib/libast/string/wc2utf8.c b/src/lib/libast/string/wc2utf8.c
new file mode 100644
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--- /dev/null
+++ b/src/lib/libast/string/wc2utf8.c
@@ -0,0 +1,74 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+/*
+ * Glenn Fowler
+ * AT&T Research
+ *
+ * convert wide character to utf8 in s
+ * s must have room for at least 6 bytes
+ * number of chars in placed in s returned
+ * thanks Tom Duff
+ */
+
+#include <ast.h>
+
+typedef struct Utf8_s
+{
+	uint32_t	range;
+	unsigned short	prefix;
+	unsigned short	shift;
+} Utf8_t;
+
+static const Utf8_t	ops[] =
+{
+	{ 0x00000080, 0x00,  0 },
+	{ 0x00000800, 0xc0,  6 },
+	{ 0x00010000, 0xe0, 12 },
+	{ 0x00200000, 0xf0, 18 },
+	{ 0x04000000, 0xf8, 24 },
+	{ 0x80000000, 0xfc, 30 }
+};
+
+int
+wc2utf8(register char* s, register uint32_t w)
+{
+	register int	i;
+	char*		b;
+
+	for (i = 0; i < elementsof(ops); i++)
+		if (w < ops[i].range)
+		{
+			b = s;
+			*s++ = ops[i].prefix | (w >> ops[i].shift);
+			switch (ops[i].shift)
+			{
+			case 30:	*s++ = 0x80 | ((w >> 24) & 0x3f);
+			case 24:	*s++ = 0x80 | ((w >> 18) & 0x3f);
+			case 18:	*s++ = 0x80 | ((w >> 12) & 0x3f);
+			case 12:	*s++ = 0x80 | ((w >>  6) & 0x3f);
+			case  6:	*s++ = 0x80 | (w & 0x3f);
+			}
+			return s - b;
+		}
+	return 0;
+}