stdio.h revision 7d56ccbfaac2b702e4be0f71038efb7f251ef637
1/*	$OpenBSD: stdio.h,v 1.35 2006/01/13 18:10:09 miod Exp $	*/
2/*	$NetBSD: stdio.h,v 1.18 1996/04/25 18:29:21 jtc Exp $	*/
3
4/*-
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Chris Torek.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	@(#)stdio.h	5.17 (Berkeley) 6/3/91
36 */
37
38#ifndef	_STDIO_H_
39#define	_STDIO_H_
40
41#include <sys/cdefs.h>
42#include <sys/_types.h>
43
44#include <stdarg.h>
45#include <stddef.h>
46
47#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
48#include <sys/types.h>	/* XXX should be removed */
49#endif
50
51#ifndef _SIZE_T_DEFINED_
52#define _SIZE_T_DEFINED_
53typedef unsigned int  size_t;
54#endif
55
56#ifndef _SSIZE_T_DEFINED_
57#define _SSIZE_T_DEFINED_
58typedef long int  ssize_t;
59#endif
60
61#ifndef	_OFF_T_DEFINED_
62#define	_OFF_T_DEFINED_
63typedef	long    off_t;
64#endif
65
66#define __need_NULL
67#include <stddef.h>
68
69#define	_FSTDIO			/* Define for new stdio with functions. */
70
71typedef off_t fpos_t;		/* stdio file position type */
72
73/*
74 * NB: to fit things in six character monocase externals, the stdio
75 * code uses the prefix `__s' for stdio objects, typically followed
76 * by a three-character attempt at a mnemonic.
77 */
78
79/* stdio buffers */
80struct __sbuf {
81	unsigned char *_base;
82	int	_size;
83};
84
85/*
86 * stdio state variables.
87 *
88 * The following always hold:
89 *
90 *	if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
91 *		_lbfsize is -_bf._size, else _lbfsize is 0
92 *	if _flags&__SRD, _w is 0
93 *	if _flags&__SWR, _r is 0
94 *
95 * This ensures that the getc and putc macros (or inline functions) never
96 * try to write or read from a file that is in `read' or `write' mode.
97 * (Moreover, they can, and do, automatically switch from read mode to
98 * write mode, and back, on "r+" and "w+" files.)
99 *
100 * _lbfsize is used only to make the inline line-buffered output stream
101 * code as compact as possible.
102 *
103 * _ub, _up, and _ur are used when ungetc() pushes back more characters
104 * than fit in the current _bf, or when ungetc() pushes back a character
105 * that does not match the previous one in _bf.  When this happens,
106 * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
107 * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
108 *
109 * NOTE: if you change this structure, you also need to update the
110 * std() initializer in findfp.c.
111 */
112typedef	struct __sFILE {
113	unsigned char *_p;	/* current position in (some) buffer */
114	int	_r;		/* read space left for getc() */
115	int	_w;		/* write space left for putc() */
116	short	_flags;		/* flags, below; this FILE is free if 0 */
117	short	_file;		/* fileno, if Unix descriptor, else -1 */
118	struct	__sbuf _bf;	/* the buffer (at least 1 byte, if !NULL) */
119	int	_lbfsize;	/* 0 or -_bf._size, for inline putc */
120
121	/* operations */
122	void	*_cookie;	/* cookie passed to io functions */
123	int	(*_close)(void *);
124	int	(*_read)(void *, char *, int);
125	fpos_t	(*_seek)(void *, fpos_t, int);
126	int	(*_write)(void *, const char *, int);
127
128	/* extension data, to avoid further ABI breakage */
129	struct	__sbuf _ext;
130	/* data for long sequences of ungetc() */
131	unsigned char *_up;	/* saved _p when _p is doing ungetc data */
132	int	_ur;		/* saved _r when _r is counting ungetc data */
133
134	/* tricks to meet minimum requirements even when malloc() fails */
135	unsigned char _ubuf[3];	/* guarantee an ungetc() buffer */
136	unsigned char _nbuf[1];	/* guarantee a getc() buffer */
137
138	/* separate buffer for fgetln() when line crosses buffer boundary */
139	struct	__sbuf _lb;	/* buffer for fgetln() */
140
141	/* Unix stdio files get aligned to block boundaries on fseek() */
142	int	_blksize;	/* stat.st_blksize (may be != _bf._size) */
143	fpos_t	_offset;	/* current lseek offset */
144} FILE;
145
146__BEGIN_DECLS
147extern FILE __sF[];
148__END_DECLS
149
150#define	__SLBF	0x0001		/* line buffered */
151#define	__SNBF	0x0002		/* unbuffered */
152#define	__SRD	0x0004		/* OK to read */
153#define	__SWR	0x0008		/* OK to write */
154	/* RD and WR are never simultaneously asserted */
155#define	__SRW	0x0010		/* open for reading & writing */
156#define	__SEOF	0x0020		/* found EOF */
157#define	__SERR	0x0040		/* found error */
158#define	__SMBF	0x0080		/* _buf is from malloc */
159#define	__SAPP	0x0100		/* fdopen()ed in append mode */
160#define	__SSTR	0x0200		/* this is an sprintf/snprintf string */
161#define	__SOPT	0x0400		/* do fseek() optimisation */
162#define	__SNPT	0x0800		/* do not do fseek() optimisation */
163#define	__SOFF	0x1000		/* set iff _offset is in fact correct */
164#define	__SMOD	0x2000		/* true => fgetln modified _p text */
165#define	__SALC	0x4000		/* allocate string space dynamically */
166#define	__SIGN	0x8000		/* ignore this file in _fwalk */
167
168/*
169 * The following three definitions are for ANSI C, which took them
170 * from System V, which brilliantly took internal interface macros and
171 * made them official arguments to setvbuf(), without renaming them.
172 * Hence, these ugly _IOxxx names are *supposed* to appear in user code.
173 *
174 * Although numbered as their counterparts above, the implementation
175 * does not rely on this.
176 */
177#define	_IOFBF	0		/* setvbuf should set fully buffered */
178#define	_IOLBF	1		/* setvbuf should set line buffered */
179#define	_IONBF	2		/* setvbuf should set unbuffered */
180
181#define	BUFSIZ	1024		/* size of buffer used by setbuf */
182
183#define	EOF	(-1)
184
185/*
186 * FOPEN_MAX is a minimum maximum, and should be the number of descriptors
187 * that the kernel can provide without allocation of a resource that can
188 * fail without the process sleeping.  Do not use this for anything.
189 */
190#define	FOPEN_MAX	20	/* must be <= OPEN_MAX <sys/syslimits.h> */
191#define	FILENAME_MAX	1024	/* must be <= PATH_MAX <sys/syslimits.h> */
192
193/* System V/ANSI C; this is the wrong way to do this, do *not* use these. */
194#if __BSD_VISIBLE || __XPG_VISIBLE
195#define	P_tmpdir	"/tmp/"
196#endif
197#define	L_tmpnam	1024	/* XXX must be == PATH_MAX */
198#define	TMP_MAX		308915776
199
200#ifndef SEEK_SET
201#define	SEEK_SET	0	/* set file offset to offset */
202#endif
203#ifndef SEEK_CUR
204#define	SEEK_CUR	1	/* set file offset to current plus offset */
205#endif
206#ifndef SEEK_END
207#define	SEEK_END	2	/* set file offset to EOF plus offset */
208#endif
209
210#define	stdin	(&__sF[0])
211#define	stdout	(&__sF[1])
212#define	stderr	(&__sF[2])
213
214/*
215 * Functions defined in ANSI C standard.
216 */
217__BEGIN_DECLS
218void	 clearerr(FILE *);
219int	 fclose(FILE *);
220int	 feof(FILE *);
221int	 ferror(FILE *);
222int	 fflush(FILE *);
223int	 fgetc(FILE *);
224int	 fgetpos(FILE *, fpos_t *);
225char	*fgets(char *, int, FILE *);
226FILE	*fopen(const char *, const char *);
227int	 fprintf(FILE *, const char *, ...)
228		__attribute__((__format__ (printf, 2, 3)))
229		__attribute__((__nonnull__ (2)));
230int	 fputc(int, FILE *);
231int	 fputs(const char *, FILE *);
232size_t	 fread(void *, size_t, size_t, FILE *);
233FILE	*freopen(const char *, const char *, FILE *);
234int	 fscanf(FILE *, const char *, ...)
235		__attribute__ ((__format__ (scanf, 2, 3)))
236		__attribute__ ((__nonnull__ (2)));
237int	 fseek(FILE *, long, int);
238int	 fseeko(FILE *, off_t, int);
239int	 fsetpos(FILE *, const fpos_t *);
240long	 ftell(FILE *);
241off_t	 ftello(FILE *);
242size_t	 fwrite(const void *, size_t, size_t, FILE *);
243int	 getc(FILE *);
244int	 getchar(void);
245ssize_t	 getdelim(char ** __restrict, size_t * __restrict, int,
246	    FILE * __restrict);
247ssize_t	 getline(char ** __restrict, size_t * __restrict, FILE * __restrict);
248char	*gets(char *);
249#if __BSD_VISIBLE && !defined(__SYS_ERRLIST)
250#define __SYS_ERRLIST
251
252extern int sys_nerr;			/* perror(3) external variables */
253extern char *sys_errlist[];
254#endif
255void	 perror(const char *);
256int	 printf(const char *, ...)
257		__attribute__((__format__ (printf, 1, 2)))
258		__attribute__((__nonnull__ (1)));
259int	 putc(int, FILE *);
260int	 putchar(int);
261int	 puts(const char *);
262int	 remove(const char *);
263int	 rename(const char *, const char *);
264void	 rewind(FILE *);
265int	 scanf(const char *, ...)
266		__attribute__ ((__format__ (scanf, 1, 2)))
267		__attribute__ ((__nonnull__ (1)));
268void	 setbuf(FILE *, char *);
269int	 setvbuf(FILE *, char *, int, size_t);
270int	 sprintf(char *, const char *, ...)
271		__attribute__((__format__ (printf, 2, 3)))
272		__attribute__((__nonnull__ (2)));
273int	 sscanf(const char *, const char *, ...)
274		__attribute__ ((__format__ (scanf, 2, 3)))
275		__attribute__ ((__nonnull__ (2)));
276FILE	*tmpfile(void);
277char	*tmpnam(char *);
278int	 ungetc(int, FILE *);
279int	 vfprintf(FILE *, const char *, __va_list)
280		__attribute__((__format__ (printf, 2, 0)))
281		__attribute__((__nonnull__ (2)));
282int	 vprintf(const char *, __va_list)
283		__attribute__((__format__ (printf, 1, 0)))
284		__attribute__((__nonnull__ (1)));
285int	 vsprintf(char *, const char *, __va_list)
286		__attribute__((__format__ (printf, 2, 0)))
287		__attribute__((__nonnull__ (2)));
288
289#if __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE
290int	 snprintf(char *, size_t, const char *, ...)
291		__attribute__((__format__ (printf, 3, 4)))
292		__attribute__((__nonnull__ (3)));
293int	 vfscanf(FILE *, const char *, __va_list)
294		__attribute__((__format__ (scanf, 2, 0)))
295		__attribute__((__nonnull__ (2)));
296int	 vscanf(const char *, __va_list)
297		__attribute__((__format__ (scanf, 1, 0)))
298		__attribute__((__nonnull__ (1)));
299int	 vsnprintf(char *, size_t, const char *, __va_list)
300		__attribute__((__format__ (printf, 3, 0)))
301		__attribute__((__nonnull__ (3)));
302int	 vsscanf(const char *, const char *, __va_list)
303		__attribute__((__format__ (scanf, 2, 0)))
304		__attribute__((__nonnull__ (2)));
305#endif /* __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE */
306
307__END_DECLS
308
309
310/*
311 * Functions defined in POSIX 1003.1.
312 */
313#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
314#define	L_ctermid	1024	/* size for ctermid(); PATH_MAX */
315#define L_cuserid	9	/* size for cuserid(); UT_NAMESIZE + 1 */
316
317__BEGIN_DECLS
318#if 0 /* MISSING FROM BIONIC */
319char	*ctermid(char *);
320char	*cuserid(char *);
321#endif /* MISSING */
322FILE	*fdopen(int, const char *);
323int	 fileno(FILE *);
324
325#if (__POSIX_VISIBLE >= 199209)
326int	 pclose(FILE *);
327FILE	*popen(const char *, const char *);
328#endif
329
330#if __POSIX_VISIBLE >= 199506
331void	 flockfile(FILE *);
332int	 ftrylockfile(FILE *);
333void	 funlockfile(FILE *);
334
335/*
336 * These are normally used through macros as defined below, but POSIX
337 * requires functions as well.
338 */
339int	 getc_unlocked(FILE *);
340int	 getchar_unlocked(void);
341int	 putc_unlocked(int, FILE *);
342int	 putchar_unlocked(int);
343#endif /* __POSIX_VISIBLE >= 199506 */
344
345#if __XPG_VISIBLE
346char	*tempnam(const char *, const char *);
347#endif
348__END_DECLS
349
350#endif /* __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE */
351
352/*
353 * Routines that are purely local.
354 */
355#if __BSD_VISIBLE
356__BEGIN_DECLS
357int	 asprintf(char **, const char *, ...)
358		__attribute__((__format__ (printf, 2, 3)))
359		__attribute__((__nonnull__ (2)));
360char	*fgetln(FILE *, size_t *);
361int	 fpurge(FILE *);
362int	 getw(FILE *);
363int	 putw(int, FILE *);
364void	 setbuffer(FILE *, char *, int);
365int	 setlinebuf(FILE *);
366int	 vasprintf(char **, const char *, __va_list)
367		__attribute__((__format__ (printf, 2, 0)))
368		__attribute__((__nonnull__ (2)));
369__END_DECLS
370
371/*
372 * Stdio function-access interface.
373 */
374__BEGIN_DECLS
375FILE	*funopen(const void *,
376		int (*)(void *, char *, int),
377		int (*)(void *, const char *, int),
378		fpos_t (*)(void *, fpos_t, int),
379		int (*)(void *));
380__END_DECLS
381#define	fropen(cookie, fn) funopen(cookie, fn, 0, 0, 0)
382#define	fwopen(cookie, fn) funopen(cookie, 0, fn, 0, 0)
383#endif /* __BSD_VISIBLE */
384
385/*
386 * Functions internal to the implementation.
387 */
388__BEGIN_DECLS
389int	__srget(FILE *);
390int	__swbuf(int, FILE *);
391__END_DECLS
392
393/*
394 * The __sfoo macros are here so that we can
395 * define function versions in the C library.
396 */
397#define	__sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
398#if defined(__GNUC__)
399static __inline int __sputc(int _c, FILE *_p) {
400	if (--_p->_w >= 0 || (_p->_w >= _p->_lbfsize && (char)_c != '\n'))
401		return (*_p->_p++ = _c);
402	else
403		return (__swbuf(_c, _p));
404}
405#else
406/*
407 * This has been tuned to generate reasonable code on the vax using pcc.
408 */
409#define	__sputc(c, p) \
410	(--(p)->_w < 0 ? \
411		(p)->_w >= (p)->_lbfsize ? \
412			(*(p)->_p = (c)), *(p)->_p != '\n' ? \
413				(int)*(p)->_p++ : \
414				__swbuf('\n', p) : \
415			__swbuf((int)(c), p) : \
416		(*(p)->_p = (c), (int)*(p)->_p++))
417#endif
418
419#define	__sfeof(p)	(((p)->_flags & __SEOF) != 0)
420#define	__sferror(p)	(((p)->_flags & __SERR) != 0)
421#define	__sclearerr(p)	((void)((p)->_flags &= ~(__SERR|__SEOF)))
422#define	__sfileno(p)	((p)->_file)
423
424extern	int __isthreaded;
425
426#define	feof(p)		(!__isthreaded ? __sfeof(p) : (feof)(p))
427#define	ferror(p)	(!__isthreaded ? __sferror(p) : (ferror)(p))
428#define	clearerr(p)	(!__isthreaded ? __sclearerr(p) : (clearerr)(p))
429
430#if __POSIX_VISIBLE
431#define	fileno(p)	(!__isthreaded ? __sfileno(p) : (fileno)(p))
432#endif
433
434#define	getc(fp)	(!__isthreaded ? __sgetc(fp) : (getc)(fp))
435
436#if __BSD_VISIBLE
437/*
438 * The macro implementations of putc and putc_unlocked are not
439 * fully POSIX compliant; they do not set errno on failure
440 */
441#define putc(x, fp)	(!__isthreaded ? __sputc(x, fp) : (putc)(x, fp))
442#endif /* __BSD_VISIBLE */
443
444#ifndef lint
445#if __POSIX_VISIBLE >= 199506
446#define	getc_unlocked(fp)	__sgetc(fp)
447/*
448 * The macro implementations of putc and putc_unlocked are not
449 * fully POSIX compliant; they do not set errno on failure
450 */
451#if __BSD_VISIBLE
452#define putc_unlocked(x, fp)	__sputc(x, fp)
453#endif /* __BSD_VISIBLE */
454#endif /* __POSIX_VISIBLE >= 199506 */
455#endif /* lint */
456
457#define	getchar()	getc(stdin)
458#define	putchar(x)	putc(x, stdout)
459#define	getchar_unlocked()	getc_unlocked(stdin)
460#define	putchar_unlocked(c)	putc_unlocked(c, stdout)
461
462#ifdef _GNU_SOURCE
463/*
464 * glibc defines dprintf(int, const char*, ...), which is poorly named
465 * and likely to conflict with locally defined debugging printfs
466 * fdprintf is a better name, and some programs that use fdprintf use a
467 * #define fdprintf dprintf for compatibility
468 */
469__BEGIN_DECLS
470int fdprintf(int, const char*, ...)
471		__attribute__((__format__ (printf, 2, 3)))
472		__attribute__((__nonnull__ (2)));
473int vfdprintf(int, const char*, __va_list)
474		__attribute__((__format__ (printf, 2, 0)))
475		__attribute__((__nonnull__ (2)));
476__END_DECLS
477#endif /* _GNU_SOURCE */
478
479#if defined(__BIONIC_FORTIFY_INLINE)
480
481__BIONIC_FORTIFY_INLINE
482__attribute__((__format__ (printf, 3, 0)))
483__attribute__((__nonnull__ (3)))
484int vsnprintf(char *dest, size_t size, const char *format, __va_list ap)
485{
486    return __builtin___vsnprintf_chk(dest, size, 0,
487        __builtin_object_size(dest, 0), format, ap);
488}
489
490__BIONIC_FORTIFY_INLINE
491__attribute__((__format__ (printf, 2, 0)))
492__attribute__((__nonnull__ (2)))
493int vsprintf(char *dest, const char *format, __va_list ap)
494{
495    return __builtin___vsprintf_chk(dest, 0,
496        __builtin_object_size(dest, 0), format, ap);
497}
498
499__BIONIC_FORTIFY_INLINE
500__attribute__((__format__ (printf, 3, 4)))
501__attribute__((__nonnull__ (3)))
502int snprintf(char *str, size_t size, const char *format, ...)
503{
504    return __builtin___snprintf_chk(str, size, 0,
505        __builtin_object_size(str, 0), format, __builtin_va_arg_pack());
506}
507
508__BIONIC_FORTIFY_INLINE
509__attribute__((__format__ (printf, 2, 3)))
510__attribute__((__nonnull__ (2)))
511int sprintf(char *dest, const char *format, ...)
512{
513    return __builtin___sprintf_chk(dest, 0,
514        __builtin_object_size(dest, 0), format, __builtin_va_arg_pack());
515}
516
517extern char *__fgets_real(char *, int, FILE *)
518    __asm__(__USER_LABEL_PREFIX__ "fgets");
519extern void __fgets_too_big_error()
520    __attribute__((__error__("fgets called with size bigger than buffer")));
521extern void __fgets_too_small_error()
522    __attribute__((__error__("fgets called with size less than zero")));
523extern char *__fgets_chk(char *, int, FILE *, size_t);
524
525__BIONIC_FORTIFY_INLINE
526char *fgets(char *dest, int size, FILE *stream)
527{
528    size_t bos = __builtin_object_size(dest, 0);
529
530    // Compiler can prove, at compile time, that the passed in size
531    // is always negative. Force a compiler error.
532    if (__builtin_constant_p(size) && (size < 0)) {
533        __fgets_too_small_error();
534    }
535
536    // Compiler doesn't know destination size. Don't call __fgets_chk
537    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
538        return __fgets_real(dest, size, stream);
539    }
540
541    // Compiler can prove, at compile time, that the passed in size
542    // is always <= the actual object size. Don't call __fgets_chk
543    if (__builtin_constant_p(size) && (size <= bos)) {
544        return __fgets_real(dest, size, stream);
545    }
546
547    // Compiler can prove, at compile time, that the passed in size
548    // is always > the actual object size. Force a compiler error.
549    if (__builtin_constant_p(size) && (size > bos)) {
550        __fgets_too_big_error();
551    }
552
553    return __fgets_chk(dest, size, stream, bos);
554}
555
556#endif /* defined(__BIONIC_FORTIFY_INLINE) */
557
558#endif /* _STDIO_H_ */
559