1 files changed, 47 insertions, 0 deletions
diff --git a/src/usr.bin/lam/utf8.c b/src/usr.bin/lam/utf8.c
new file mode 100644
index 0000000..0f68924
--- /dev/null
+++ b/src/usr.bin/lam/utf8.c
@@ -0,0 +1,47 @@
+/* $OpenBSD: utf8.c,v 1.1 2018/07/29 11:27:15 schwarze Exp $ */
+/*
+ * Copyright (c) 2018 Ingo Schwarze <schwarze@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <wchar.h>
+
+/*
+ * Measure the display width of the multibyte string.
+ * Treat invalid bytes and non-printable characters as width 1.
+ * Truncate the string to a display width of maxwidth.
+ * Return the total width, possibly after truncation.
+ */
+int
+mbswidth_truncate(char *mbs, int maxwidth)
+{
+	wchar_t	 wc;
+	int	 len, width, sum;
+
+	sum = 0;
+	while (*mbs != '\0') {
+		if ((len = mbtowc(&wc, mbs, MB_CUR_MAX)) == -1)
+			len = width = 1;
+		else if ((width = wcwidth(wc)) < 0)
+			width = 1;
+		if (sum + width > maxwidth) {
+			*mbs = '\0';
+			break;
+		}
+		sum += width;
+		mbs += len;
+	}
+	return sum;
+}