--- /dev/null
+/* 4.4BSD utility functions for error messages.
+ Copyright (C) 1995-2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _ERR_H
+#define _ERR_H 1
+
+#include <features.h>
+
+#define __need___va_list
+#include <stdarg.h>
+#ifndef __GNUC_VA_LIST
+# define __gnuc_va_list void *
+#endif
+
+__BEGIN_DECLS
+
+/* Print "program: ", FORMAT, ": ", the standard error string for errno,
+ and a newline, on stderr. */
+extern void warn (const char *__format, ...)
+ __attribute__ ((__format__ (__printf__, 1, 2)));
+extern void vwarn (const char *__format, __gnuc_va_list)
+ __attribute__ ((__format__ (__printf__, 1, 0)));
+
+/* Likewise, but without ": " and the standard error string. */
+extern void warnx (const char *__format, ...)
+ __attribute__ ((__format__ (__printf__, 1, 2)));
+extern void vwarnx (const char *__format, __gnuc_va_list)
+ __attribute__ ((__format__ (__printf__, 1, 0)));
+
+/* Likewise, and then exit with STATUS. */
+extern void err (int __status, const char *__format, ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 2, 3)));
+extern void verr (int __status, const char *__format, __gnuc_va_list)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 2, 0)));
+extern void errx (int __status, const char *__format, ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 2, 3)));
+extern void verrx (int __status, const char *, __gnuc_va_list)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 2, 0)));
+
+__END_DECLS
+
+#endif /* err.h */