--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/C/port/err.h	Sun Mar 08 14:26:33 2015 +0100
@@ -0,0 +1,82 @@
+/*
+ * err.h -- formtted error messages (portable version)
+ *
+ * Copyright (c) 2011, 2012, David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or 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.
+ */
+
+#ifndef _ERR_H_
+#define _ERR_H_
+
+#include <stdarg.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Attribute noreturn may helps. This may produce a warning with GCC 4.5:
+ *
+ * int a;
+ *
+ * if ((a = getstate() < 0)
+ *	errx(1, "State failed");
+ *
+ * Because compilator does not know that errx will call exit may produce
+ * a warning like `a may be used uninitialized'.
+ */
+
+#if defined(__GNUC__)
+#  define __at_noreturn	__attribute__ ((noreturn))
+#elif defined(_MSC_VER)
+#  define __at_noreturn	__declspec(noreturn)
+#endif
+
+/*
+ * err() functions append the format message to the stderr FILE pointer. They
+ * also append the system error using strerror(errno). Then the functions exit
+ * with the error code given as first argument.
+ */
+
+void	err(int, const char *, ...) __at_noreturn;
+void	verr(int, const char *, va_list) __at_noreturn;
+
+/*
+ * errx() functions are similar to err() except that they do not append the
+ * system error message.
+ */
+
+void	errx(int, const char *, ...) __at_noreturn;
+void	verrx(int, const char *, va_list) __at_noreturn;
+
+/*
+ * warn() functions are similar to err() but they do not call exit().
+ */
+
+void	warn(const char *, ...);
+void	vwarn(const char *, va_list);
+
+/*
+ * warnx() functions are similar to warn() except that they do not append the
+ * system error message.
+ */
+
+void	warnx(const char *, ...);
+void	vwarnx(const char *, va_list);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _ERR_H_ */