#include <db_cxx.h> DbEnv::msg(const char *fmt, ...);
The DbEnv::msg() and
Db::msg()
methods provide
informational messaging functionality for applications written using the
Berkeley DB library.
The Db::msg() and DbEnv::msg() methods constructs an informational message consisting of the following elements:
An optional prefix string
If no informational callback function has been set using the DbEnv::set_msgcall() method, any prefix string specified using the DbEnv::set_msgpfx() method.
An optional printf-style message
The supplied message fmt, if non-NULL, in which the ANSI C X3.159-1989 (ANSI C) printf function specifies how subsequent parameters are converted for output.
This constructed informational message is then handled as follows:
If an informational callback function has been set (see Db::set_msgcall() and DbEnv::set_msgcall() ), that function is called with two parameters: any prefix string specified (see Db::set_msgpfx() and DbEnv::set_msgpfx() ) and the informational message.
If a C library FILE * has been set (see Db::set_msgfile() and DbEnv::set_msgfile() ), the informational message is written to that output stream.
If a C++ ostream has been set (see DbEnv::set_message_stream() and Db::set_message_stream()), the informational message is written to that stream.
If none of these output options have been configured, the message is written to stdout, the standard output stream.
The total length of the message written by this method, including the prefix string, can be no longer than 4096.