initial import

from
http://www.informit.com/store/programming-with-posix-threads-9780201633924

errors.h

@@ -0,0 +1,49 @@
+#ifndef __errors_h
+#define __errors_h
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * Define a macro that can be used for diagnostic output from
+ * examples. When compiled -DDEBUG, it results in calling printf
+ * with the specified argument list. When DEBUG is not defined, it
+ * expands to nothing.
+ */
+#ifdef DEBUG
+# define DPRINTF(arg) printf arg
+#else
+# define DPRINTF(arg)
+#endif
+
+/*
+ * NOTE: the "do {" ... "} while (0);" bracketing around the macros
+ * allows the err_abort and errno_abort macros to be used as if they
+ * were function calls, even in contexts where a trailing ";" would
+ * generate a null statement. For example,
+ *
+ *      if (status != 0)
+ *          err_abort (status, "message");
+ *      else
+ *          return status;
+ *
+ * will not compile if err_abort is a macro ending with "}", because
+ * C does not expect a ";" to follow the "}". Because C does expect
+ * a ";" following the ")" in the do...while construct, err_abort and
+ * errno_abort can be used as if they were function calls.
+ */
+#define err_abort(code,text) do { \
+    fprintf (stderr, "%s at \"%s\":%d: %s\n", \
+        text, __FILE__, __LINE__, strerror (code)); \
+    abort (); \
+    } while (0)
+#define errno_abort(text) do { \
+    fprintf (stderr, "%s at \"%s\":%d: %s\n", \
+        text, __FILE__, __LINE__, strerror (errno)); \
+    abort (); \
+    } while (0)
+
+#endif