Used to send messages from the library to the user.
Occasionally, the library generates warnings or other messages in plain english to inform the human user. These are informational only and can be ignored if not wanted.
|file ||may be a file handle returned from open() if this message pertains to a specific open file, or NULL if not related to a specific file. |
|format ||a printf() style format string. It does NOT include a trailing newline. |
- See also: