+/**
+ * program name, defined by the program for show_version().
+ */
+extern const char program_name[];
+
+/**
+ * program birth year, defined by the program for show_banner()
+ */
+extern const int program_birth_year;
+
+/**
+ * Parses a string and returns its corresponding value as a double.
+ * Exits from the application if the string cannot be correctly
+ * parsed or the corresponding value is invalid.
+ *
+ * @param context the context of the value to be set (e.g. the
+ * corresponding commandline option name)
+ * @param numstr the string to be parsed
+ * @param type the type (OPT_INT64 or OPT_FLOAT) as which the
+ * string should be parsed
+ * @param min the minimum valid accepted value
+ * @param max the maximum valid accepted value
+ */
+double parse_number_or_die(const char *context, const char *numstr, int type, double min, double max);
+
+/**
+ * Parses a string specifying a time and returns its corresponding
+ * value as a number of microseconds. Exits from the application if
+ * the string cannot be correctly parsed.
+ *
+ * @param context the context of the value to be set (e.g. the
+ * corresponding commandline option name)
+ * @param timestr the string to be parsed
+ * @param is_duration a flag which tells how to interpret \p timestr, if
+ * not zero \p timestr is interpreted as a duration, otherwise as a
+ * date
+ *
+ * @see parse_date()
+ */
+int64_t parse_time_or_die(const char *context, const char *timestr, int is_duration);
+