haiku/headers/posix/stdio_pre.h
Axel Dörfler 79d76063c3 Added stdio post/pre includes for our BeOS compatible stdio implementation.
stdio.h will follow later (the headers are currently unused).


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2689 a95241bf-73f2-0310-859d-f6bbb57e9c96
2003-02-11 19:37:58 +00:00

120 lines
4.4 KiB
C

#ifndef _STDIO_PRE_H_
#define _STDIO_PRE_H_
/*
** Distributed under the terms of the OpenBeOS License.
*/
// Details of the BeOS compatible stdio implementation
// Structure definitions
// ToDo: this is a work in progress to make our stdio
// BeOS' GNU/libio (almost) binary compatible
// We are not yet compatible!
// Currently only function names are compatible
#ifndef _STDIO_H_
# error "This file must be included from stdio.h!"
#endif
extern char *_single_threaded;
/* This determines if a process runs single threaded or not */
/* stdio buffers */
struct __sbuf {
unsigned char *_base;
int _size;
};
/*
* stdio state variables.
*
* The following always hold:
*
*if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
* _lbfsize is -_bf._size, else _lbfsize is 0
*if _flags&__SRD, _w is 0
*if _flags&__SWR, _r is 0
*
* This ensures that the getc and putc macros (or inline functions) never
* try to write or read from a file that is in `read' or `write' mode.
* (Moreover, they can, and do, automatically switch from read mode to
* write mode, and back, on "r+" and "w+" files.)
*
* _lbfsize is used only to make the inline line-buffered output stream
* code as compact as possible.
*
* _ub, _up, and _ur are used when ungetc() pushes back more characters
* than fit in the current _bf, or when ungetc() pushes back a character
* that does not match the previous one in _bf. When this happens,
* _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
* _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
*/
typedef struct __FILE {
// ToDo: these fields must be maintained (at the same position)!
//int _flags; /* High-order word is _IO_MAGIC; rest is flags. */
char *_IO_read_ptr; /* Current read pointer */
char *_IO_read_end; /* End of get area. */
//char *_IO_read_base; /* Start of putback+get area. */
//char *_IO_write_base; /* Start of put area. */
char *_IO_write_ptr; /* Current put pointer. */
char *_IO_write_end; /* End of put area. */
unsigned char *_p;/* current position in (some) buffer */
int _r; /* read space left for getc() */
int _w; /* write space left for putc() */
short _flags; /* flags, below; this FILE is free if 0 */
short _file; /* fileno, if Unix descriptor, else -1 */
struct __sbuf _bf; /* the buffer (at least 1 byte, if !NULL) */
int _lbfsize;/* 0 or -_bf._size, for inline putc */
/* operations */
void *_cookie;/* cookie passed to io functions */
int (*_close) (void *);
int (*_read) (void *, char *, int);
fpos_t (*_seek) (void *, fpos_t, int);
int (*_write) (void *, const char *, int);
/* separate buffer for long sequences of ungetc() */
struct __sbuf _ub; /* ungetc buffer */
unsigned char *_up; /* saved _p when _p is doing ungetc data */
int _ur;/* saved _r when _r is counting ungetc data */
/* tricks to meet minimum requirements even when malloc() fails */
unsigned char _ubuf[3]; /* guarantee an ungetc() buffer */
unsigned char _nbuf[1]; /* guarantee a getc() buffer */
/* separate buffer for fgetln() when line crosses buffer boundary */
struct __sbuf _lb; /* buffer for fgetln() */
/* Unix stdio files get aligned to block boundaries on fseek() */
int _blksize;/* stat.st_blksize (may be != _bf._size) */
fpos_t _offset;/* current lseek offset */
// ToDo: add structure reserved fields
} FILE;
#define __SLBF 0x0001 /* line buffered */
#define __SNBF 0x0002 /* unbuffered */
#define __SRD 0x0004 /* OK to read */
#define __SWR 0x0008 /* OK to write */
/* RD and WR are never simultaneously asserted */
#define __SRW 0x0010 /* open for reading & writing */
#define __SEOF 0x0020 /* found EOF */
#define __SERR 0x0040 /* found error */
#define __SMBF 0x0080 /* _buf is from malloc */
#define __SAPP 0x0100 /* fdopen()ed in append mode */
#define __SSTR 0x0200 /* this is an sprintf/snprintf string */
#define __SOPT 0x0400 /* do fseek() optimisation */
#define __SNPT 0x0800 /* do not do fseek() optimisation */
#define __SOFF 0x1000 /* set iff _offset is in fact correct */
#define __SMOD 0x2000 /* true => fgetln modified _p text */
#define __SALC 0x4000 /* allocate string space dynamically */
#define __PRINTFLIKE(format, varargs) __attribute__ ((__format__ (__printf__, format, varargs)));
#define __SCANFLIKE(format, varargs) __attribute__((__format__ (__scanf__, format, varargs)))
#endif /* _STDIO_PRE_H_ */