int readfile __PARMS((char_u *fname, char_u *sfname, linenr_t from, int newfile, linenr_t lines_to_skip, linenr_t lines_to_read, int filtering));
int buf_write __PARMS((BUF *buf, char_u *fname, char_u *sfname, linenr_t start, linenr_t end, int append, int forceit, int reset_changed, int filtering));