#pragma once
/* OS glue functions declaration <glue.h>

   This file is part of the Public Domain C Library (PDCLib).
   Permission is granted to use, modify, and / or redistribute at will.
*/

#include "j6libc/int.h"

/* -------------------------------------------------------------------------- */
/* OS "glue", part 2                                                          */
/* These are the functions you will have to touch, as they are where PDCLib   */
/* interfaces with the operating system.                                      */
/* They operate on data types partially defined by config.h.          */
/* -------------------------------------------------------------------------- */

/* stdlib.h */

/* A system call that terminates the calling process, returning a given status
   to the environment.
*/
_Noreturn void _PDCLIB_Exit( int status );

/* A system call that adds n pages of memory to the process heap (if n is
   positive), or releases n pages from the process heap (if n is negative).
   Return a (void *) pointing to the *former* end-of-heap if successful, NULL
   otherwise.
*/
void * _PDCLIB_allocpages( int n );


/* stdio.h */

/* A system call that opens a file identified by name in a given mode. Return
   a file descriptor uniquely identifying that file.
   (The mode is the return value of the _PDCLIB_filemode() function.)
*/
_PDCLIB_fd_t _PDCLIB_open( const char * const filename, unsigned int mode );

/* A system call that writes a stream's buffer.
   Returns 0 on success, EOF on write error.
   Sets stream error flags and errno appropriately on error.
*/
int _PDCLIB_flushbuffer( struct _PDCLIB_file_t * stream );

/* A system call that fills a stream's buffer.
   Returns 0 on success, EOF on read error / EOF.
   Sets stream EOF / error flags and errno appropriately on error.
*/
int _PDCLIB_fillbuffer( struct _PDCLIB_file_t * stream );

/* A system call that repositions within a file. Returns new offset on success,
   -1 / errno on error.
*/
int64_t _PDCLIB_seek( struct _PDCLIB_file_t * stream, int64_t offset, int whence );

/* A system call that closes a file identified by given file descriptor. Return
   zero on success, non-zero otherwise.
*/
int _PDCLIB_close( _PDCLIB_fd_t fd );

/* A system call that renames a file from given old name to given new name.
   Return zero on success, non-zero otherwise. In case of failure, the file
   must still be accessible by old name. Any handling of open files etc. is
   done by standard rename() already.
*/
int _PDCLIB_rename( const char * old, const char * new );
