On Jul 24, 2007, at 11:41 AM, Simon BASLE wrote:

Use com.sun.jna.Pointer wherever FILE* is used.

You can either write a DLL function that returns the value, or do a symbol lookup on stdout (you should be able to get the address of a variable the same as a function). Something like NativeLibrary.getInstance("c").getFunction("stdout") (note that Function is derived from Pointer).

Perhaps you mean FileOutputStream? The java File class mostly just encapsulates a filesystem path, and throws in a few utility functions. Normally a File object has no real connection to the file system, while a FILE* usually is associated with an open file descriptor (an "int" value). There is a java.io.FileDescriptor which has a private int field representing a file descriptor, and it has predefined constants for stdout, stdin, and stderr (and can thus be used to create a FileIn/OutputStream.

You'd need to extract the file descriptor from the FILE* object (which is usually done with "fileno", which might be a function or a macro, so you might need to write a native method, or write a java mapping of the FILE struct so that you can access the file descriptor directly).

You probably don't really want to convert between native and java objects unless you really have to; it's generally cleaner to leave the native objects opaque and just hand them off to the next native function, rather than trying to convert their meaning into something in Java.