1 files changed, 29 insertions, 0 deletions
diff --git a/utils/encode_utf8.c b/utils/encode_utf8.c
new file mode 100644
index 00000000..731ab925
--- /dev/null
+++ b/utils/encode_utf8.c
@@ -0,0 +1,29 @@
+/*
+ * Encode a single code point as UTF-8.
+ */
+
+#include "defs.h"
+#include "misc.h"
+
+size_t encode_utf8(void *output, unsigned long ch)
+{
+    unsigned char *start = (unsigned char *)output, *p = start;
+
+    if (ch < 0x80) {
+        *p++ = ch;
+    } else if (ch < 0x800) {
+        *p++ = 0xC0 | (ch >> 6);
+        *p++ = 0x80 | (ch & 0x3F);
+    } else if (ch < 0x10000) {
+        *p++ = 0xE0 | (ch >> 12);
+        *p++ = 0x80 | ((ch >> 6) & 0x3F);
+        *p++ = 0x80 | (ch & 0x3F);
+    } else {
+        assert(ch <= 0x10FFFF);
+        *p++ = 0xF0 | (ch >> 18);
+        *p++ = 0x80 | ((ch >> 12) & 0x3F);
+        *p++ = 0x80 | ((ch >> 6) & 0x3F);
+        *p++ = 0x80 | (ch & 0x3F);
+    }
+    return p - start;
+}