diff --git a/libc/string/strcasecmp.c b/libc/string/strcasecmp.c
new file mode 100644
index 0000000..12f3a09
--- /dev/null
+++ b/libc/string/strcasecmp.c
@@ -0,0 +1,105 @@
+/*	$OpenBSD: strcasecmp.c,v 1.6 2005/08/08 08:05:37 espie Exp $	*/
+
+/*
+ * Copyright (c) 1987, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+
+typedef unsigned char u_char;
+
+/*
+ * This array is designed for mapping upper and lower case letter
+ * together for a case independent comparison.  The mappings are
+ * based upon ascii character sequences.
+ */
+static const u_char charmap[] = {
+	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
+	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
+	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
+	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
+	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
+	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
+	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
+	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
+	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
+	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
+	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
+	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
+	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
+	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
+	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
+	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
+	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
+	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
+	'\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307',
+	'\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317',
+	'\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327',
+	'\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337',
+	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
+	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
+	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
+	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
+};
+
+int
+strcasecmp(const char *s1, const char *s2)
+{
+	const u_char *cm = charmap;
+	const u_char *us1 = (const u_char *)s1;
+	const u_char *us2 = (const u_char *)s2;
+
+	while (cm[*us1] == cm[*us2++])
+		if (*us1++ == '\0')
+			return (0);
+	return (cm[*us1] - cm[*--us2]);
+}
+
+int
+strncasecmp(const char *s1, const char *s2, size_t n)
+{
+	if (n != 0) {
+		const u_char *cm = charmap;
+		const u_char *us1 = (const u_char *)s1;
+		const u_char *us2 = (const u_char *)s2;
+
+		do {
+			if (cm[*us1] != cm[*us2++])
+				return (cm[*us1] - cm[*--us2]);
+			if (*us1++ == '\0')
+      break;
+		} while (--n != 0);
+  }
+	return (0);
+}