diff --git a/libc/bionic/err.c b/libc/bionic/err.c
new file mode 100644
index 0000000..535b7e1
--- /dev/null
+++ b/libc/bionic/err.c
@@ -0,0 +1,126 @@
+/*-
+ * Copyright (c) 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 <sys/cdefs.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <errno.h>
+
+extern char *__progname;
+
+__noreturn void
+err(int eval, const char *fmt, ...)
+{
+        va_list ap;
+
+        va_start(ap, fmt);
+        verr(eval, fmt, ap);
+        va_end(ap);
+}
+
+__noreturn void
+errx(int eval, const char *fmt, ...)
+{
+        va_list ap;
+
+        va_start(ap, fmt);
+        verrx(eval, fmt, ap);
+        va_end(ap);
+}
+
+__noreturn void
+verr(int eval, const char *fmt, va_list ap)
+{
+        int sverrno;
+
+        sverrno = errno;
+        (void)fprintf(stderr, "%s: ", __progname);
+        if (fmt != NULL) {
+                (void)vfprintf(stderr, fmt, ap);
+                (void)fprintf(stderr, ": ");
+        }
+        (void)fprintf(stderr, "%s\n", strerror(sverrno));
+        exit(eval);
+}
+
+
+__noreturn void
+verrx(int eval, const char *fmt, va_list ap)
+{
+        (void)fprintf(stderr, "%s: ", __progname);
+        if (fmt != NULL)
+                (void)vfprintf(stderr, fmt, ap);
+        (void)fprintf(stderr, "\n");
+        exit(eval);
+}
+
+void
+warn(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vwarn(fmt, ap);
+	va_end(ap);
+}
+
+void
+warnx(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vwarnx(fmt, ap);
+	va_end(ap);
+}
+
+void
+vwarn(const char *fmt, va_list ap)
+{
+	int sverrno;
+
+	sverrno = errno;
+	(void)fprintf(stderr, "%s: ", __progname);
+	if (fmt != NULL) {
+		(void)vfprintf(stderr, fmt, ap);
+		(void)fprintf(stderr, ": ");
+	}
+	(void)fprintf(stderr, "%s\n", strerror(sverrno));
+}
+
+void
+vwarnx(const char *fmt, va_list ap)
+{
+	(void)fprintf(stderr, "%s: ", __progname);
+	if (fmt != NULL)
+		(void)vfprintf(stderr, fmt, ap);
+	(void)fprintf(stderr, "\n");
+}