stdio.h revision 4645c4f62df49d1ece5aabb7c9fa44ca34d30272
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/*
42 * This file must contain a reference to __gnuc_va_list so that GCC's
43 * fixincludes knows that that's what's being used for va_list, and so
44 * to leave our <stdio.h> alone. (fixincludes gets in the way of pointing
45 * one toolchain at various different sets of platform headers.)
46 * If you alter this comment, be sure to keep "__gnuc_va_list" in it!
47 */
48
49#include <sys/cdefs.h>
50#include <sys/types.h>
51
52#include <stdarg.h>
53#include <stddef.h>
54
55#define __need_NULL
56#include <stddef.h>
57
58__BEGIN_DECLS
59
60#define	_FSTDIO			/* Define for new stdio with functions. */
61
62typedef off_t fpos_t;		/* stdio file position type */
63
64/*
65 * NB: to fit things in six character monocase externals, the stdio
66 * code uses the prefix `__s' for stdio objects, typically followed
67 * by a three-character attempt at a mnemonic.
68 */
69
70/* stdio buffers */
71#if defined(__LP64__)
72struct __sbuf {
73  unsigned char* _base;
74  size_t _size;
75};
76#else
77struct __sbuf {
78	unsigned char *_base;
79	int	_size;
80};
81#endif
82
83/*
84 * stdio state variables.
85 *
86 * The following always hold:
87 *
88 *	if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR),
89 *		_lbfsize is -_bf._size, else _lbfsize is 0
90 *	if _flags&__SRD, _w is 0
91 *	if _flags&__SWR, _r is 0
92 *
93 * This ensures that the getc and putc macros (or inline functions) never
94 * try to write or read from a file that is in `read' or `write' mode.
95 * (Moreover, they can, and do, automatically switch from read mode to
96 * write mode, and back, on "r+" and "w+" files.)
97 *
98 * _lbfsize is used only to make the inline line-buffered output stream
99 * code as compact as possible.
100 *
101 * _ub, _up, and _ur are used when ungetc() pushes back more characters
102 * than fit in the current _bf, or when ungetc() pushes back a character
103 * that does not match the previous one in _bf.  When this happens,
104 * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff
105 * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.
106 *
107 * NOTE: if you change this structure, you also need to update the
108 * std() initializer in findfp.c.
109 */
110typedef	struct __sFILE {
111	unsigned char *_p;	/* current position in (some) buffer */
112	int	_r;		/* read space left for getc() */
113	int	_w;		/* write space left for putc() */
114#if defined(__LP64__)
115	int	_flags;		/* flags, below; this FILE is free if 0 */
116	int	_file;		/* fileno, if Unix descriptor, else -1 */
117#else
118	short	_flags;		/* flags, below; this FILE is free if 0 */
119	short	_file;		/* fileno, if Unix descriptor, else -1 */
120#endif
121	struct	__sbuf _bf;	/* the buffer (at least 1 byte, if !NULL) */
122	int	_lbfsize;	/* 0 or -_bf._size, for inline putc */
123
124	/* operations */
125	void	*_cookie;	/* cookie passed to io functions */
126	int	(*_close)(void *);
127	int	(*_read)(void *, char *, int);
128	fpos_t	(*_seek)(void *, fpos_t, int);
129	int	(*_write)(void *, const char *, int);
130
131	/* extension data, to avoid further ABI breakage */
132	struct	__sbuf _ext;
133	/* data for long sequences of ungetc() */
134	unsigned char *_up;	/* saved _p when _p is doing ungetc data */
135	int	_ur;		/* saved _r when _r is counting ungetc data */
136
137	/* tricks to meet minimum requirements even when malloc() fails */
138	unsigned char _ubuf[3];	/* guarantee an ungetc() buffer */
139	unsigned char _nbuf[1];	/* guarantee a getc() buffer */
140
141	/* separate buffer for fgetln() when line crosses buffer boundary */
142	struct	__sbuf _lb;	/* buffer for fgetln() */
143
144	/* Unix stdio files get aligned to block boundaries on fseek() */
145	int	_blksize;	/* stat.st_blksize (may be != _bf._size) */
146	fpos_t	_offset;	/* current lseek offset */
147} FILE;
148
149/* Legacy BSD implementation of stdin/stdout/stderr. */
150extern FILE __sF[];
151/* More obvious implementation. */
152extern FILE* stdin;
153extern FILE* stdout;
154extern FILE* stderr;
155/* C99 and earlier plus current C++ standards say these must be macros. */
156#define stdin stdin
157#define stdout stdout
158#define stderr stderr
159
160#define	__SLBF	0x0001		/* line buffered */
161#define	__SNBF	0x0002		/* unbuffered */
162#define	__SRD	0x0004		/* OK to read */
163#define	__SWR	0x0008		/* OK to write */
164	/* RD and WR are never simultaneously asserted */
165#define	__SRW	0x0010		/* open for reading & writing */
166#define	__SEOF	0x0020		/* found EOF */
167#define	__SERR	0x0040		/* found error */
168#define	__SMBF	0x0080		/* _buf is from malloc */
169#define	__SAPP	0x0100		/* fdopen()ed in append mode */
170#define	__SSTR	0x0200		/* this is an sprintf/snprintf string */
171#define	__SOPT	0x0400		/* do fseek() optimization */
172#define	__SNPT	0x0800		/* do not do fseek() optimization */
173#define	__SOFF	0x1000		/* set iff _offset is in fact correct */
174#define	__SMOD	0x2000		/* true => fgetln modified _p text */
175#define	__SALC	0x4000		/* allocate string space dynamically */
176#define	__SIGN	0x8000		/* ignore this file in _fwalk */
177
178/*
179 * The following three definitions are for ANSI C, which took them
180 * from System V, which brilliantly took internal interface macros and
181 * made them official arguments to setvbuf(), without renaming them.
182 * Hence, these ugly _IOxxx names are *supposed* to appear in user code.
183 *
184 * Although numbered as their counterparts above, the implementation
185 * does not rely on this.
186 */
187#define	_IOFBF	0		/* setvbuf should set fully buffered */
188#define	_IOLBF	1		/* setvbuf should set line buffered */
189#define	_IONBF	2		/* setvbuf should set unbuffered */
190
191#define	BUFSIZ	1024		/* size of buffer used by setbuf */
192#define	EOF	(-1)
193
194/*
195 * FOPEN_MAX is a minimum maximum, and is the number of streams that
196 * stdio can provide without attempting to allocate further resources
197 * (which could fail).  Do not use this for anything.
198 */
199
200#define	FOPEN_MAX	20	/* must be <= OPEN_MAX <sys/syslimits.h> */
201#define	FILENAME_MAX	1024	/* must be <= PATH_MAX <sys/syslimits.h> */
202
203/* System V/ANSI C; this is the wrong way to do this, do *not* use these. */
204#if __BSD_VISIBLE || __XPG_VISIBLE
205#define	P_tmpdir	"/tmp/"
206#endif
207#define	L_tmpnam	1024	/* XXX must be == PATH_MAX */
208#define	TMP_MAX		308915776
209
210#define SEEK_SET 0
211#define SEEK_CUR 1
212#define SEEK_END 2
213
214/*
215 * Functions defined in ANSI C standard.
216 */
217void	 clearerr(FILE *);
218int	 fclose(FILE *);
219int	 feof(FILE *);
220int	 ferror(FILE *);
221int	 fflush(FILE *);
222int	 fgetc(FILE *);
223char	*fgets(char * __restrict, int, FILE * __restrict);
224FILE	*fopen(const char * __restrict , const char * __restrict);
225int	 fprintf(FILE * __restrict , const char * __restrict, ...)
226		__printflike(2, 3);
227int	 fputc(int, FILE *);
228int	 fputs(const char * __restrict, FILE * __restrict);
229size_t	 fread(void * __restrict, size_t, size_t, FILE * __restrict);
230FILE	*freopen(const char * __restrict, const char * __restrict,
231	    FILE * __restrict);
232int	 fscanf(FILE * __restrict, const char * __restrict, ...)
233		__scanflike(2, 3);
234int	 fseek(FILE *, long, int);
235long	 ftell(FILE *);
236size_t	 fwrite(const void * __restrict, size_t, size_t, FILE * __restrict);
237int	 getc(FILE *);
238int	 getchar(void);
239ssize_t	 getdelim(char ** __restrict, size_t * __restrict, int,
240	    FILE * __restrict);
241ssize_t	 getline(char ** __restrict, size_t * __restrict, FILE * __restrict);
242
243void	 perror(const char *);
244int	 printf(const char * __restrict, ...)
245		__printflike(1, 2);
246int	 putc(int, FILE *);
247int	 putchar(int);
248int	 puts(const char *);
249int	 remove(const char *);
250void	 rewind(FILE *);
251int	 scanf(const char * __restrict, ...)
252		__scanflike(1, 2);
253void	 setbuf(FILE * __restrict, char * __restrict);
254int	 setvbuf(FILE * __restrict, char * __restrict, int, size_t);
255int	 sscanf(const char * __restrict, const char * __restrict, ...)
256		__scanflike(2, 3);
257FILE	*tmpfile(void);
258int	 ungetc(int, FILE *);
259int	 vfprintf(FILE * __restrict, const char * __restrict, __va_list)
260		__printflike(2, 0);
261int	 vprintf(const char * __restrict, __va_list)
262		__printflike(1, 0);
263
264int dprintf(int, const char * __restrict, ...) __printflike(2, 3);
265int vdprintf(int, const char * __restrict, __va_list) __printflike(2, 0);
266
267#ifndef __AUDIT__
268#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L
269char* gets(char*) __deprecated("gets is very unsafe; consider using fgets");
270#endif
271int sprintf(char* __restrict, const char* __restrict, ...)
272    __printflike(2, 3) __deprecated("sprintf is often misused; please use snprintf");
273char* tmpnam(char*) __deprecated("tmpnam possibly used unsafely; consider using mkstemp");
274int vsprintf(char* __restrict, const char* __restrict, __va_list)
275    __printflike(2, 0) __deprecated("vsprintf is often misused; please use vsnprintf");
276#if __XPG_VISIBLE
277char* tempnam(const char*, const char*)
278    __deprecated("tempnam possibly used unsafely; consider using mkstemp");
279#endif
280#endif
281
282extern int rename(const char*, const char*);
283extern int renameat(int, const char*, int, const char*);
284
285int	 fgetpos(FILE * __restrict, fpos_t * __restrict);
286int	 fsetpos(FILE *, const fpos_t *);
287
288int	 fseeko(FILE *, off_t, int);
289off_t	 ftello(FILE *);
290
291#if __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE
292int	 snprintf(char * __restrict, size_t, const char * __restrict, ...)
293		__printflike(3, 4);
294int	 vfscanf(FILE * __restrict, const char * __restrict, __va_list)
295		__scanflike(2, 0);
296int	 vscanf(const char *, __va_list)
297		__scanflike(1, 0);
298int	 vsnprintf(char * __restrict, size_t, const char * __restrict, __va_list)
299		__printflike(3, 0);
300int	 vsscanf(const char * __restrict, const char * __restrict, __va_list)
301		__scanflike(2, 0);
302#endif /* __ISO_C_VISIBLE >= 1999 || __BSD_VISIBLE */
303
304/*
305 * Functions defined in POSIX 1003.1.
306 */
307#if __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE
308#define	L_ctermid	1024	/* size for ctermid(); PATH_MAX */
309
310FILE	*fdopen(int, const char *);
311int	 fileno(FILE *);
312
313#if (__POSIX_VISIBLE >= 199209)
314int	 pclose(FILE *);
315FILE	*popen(const char *, const char *);
316#endif
317
318#if __POSIX_VISIBLE >= 199506
319void	 flockfile(FILE *);
320int	 ftrylockfile(FILE *);
321void	 funlockfile(FILE *);
322
323/*
324 * These are normally used through macros as defined below, but POSIX
325 * requires functions as well.
326 */
327int	 getc_unlocked(FILE *);
328int	 getchar_unlocked(void);
329int	 putc_unlocked(int, FILE *);
330int	 putchar_unlocked(int);
331#endif /* __POSIX_VISIBLE >= 199506 */
332
333#if __POSIX_VISIBLE >= 200809
334FILE* fmemopen(void*, size_t, const char*);
335FILE* open_memstream(char**, size_t*);
336#endif /* __POSIX_VISIBLE >= 200809 */
337
338#endif /* __BSD_VISIBLE || __POSIX_VISIBLE || __XPG_VISIBLE */
339
340/*
341 * Routines that are purely local.
342 */
343#if __BSD_VISIBLE
344int	 asprintf(char ** __restrict, const char * __restrict, ...)
345		__printflike(2, 3);
346char	*fgetln(FILE * __restrict, size_t * __restrict);
347int	 fpurge(FILE *);
348void	 setbuffer(FILE *, char *, int);
349int	 setlinebuf(FILE *);
350int	 vasprintf(char ** __restrict, const char * __restrict,
351    __va_list)
352		__printflike(2, 0);
353
354void clearerr_unlocked(FILE*);
355int feof_unlocked(FILE*);
356int ferror_unlocked(FILE*);
357
358/*
359 * Stdio function-access interface.
360 */
361FILE	*funopen(const void *,
362		int (*)(void *, char *, int),
363		int (*)(void *, const char *, int),
364		fpos_t (*)(void *, fpos_t, int),
365		int (*)(void *));
366
367#define	fropen(cookie, fn) funopen(cookie, fn, 0, 0, 0)
368#define	fwopen(cookie, fn) funopen(cookie, 0, fn, 0, 0)
369#endif /* __BSD_VISIBLE */
370
371extern char* __fgets_chk(char*, int, FILE*, size_t);
372extern char* __fgets_real(char*, int, FILE*) __RENAME(fgets);
373__errordecl(__fgets_too_big_error, "fgets called with size bigger than buffer");
374__errordecl(__fgets_too_small_error, "fgets called with size less than zero");
375
376#if defined(__BIONIC_FORTIFY)
377
378__BIONIC_FORTIFY_INLINE
379__printflike(3, 0)
380int vsnprintf(char *dest, size_t size, const char *format, __va_list ap)
381{
382    return __builtin___vsnprintf_chk(dest, size, 0, __bos(dest), format, ap);
383}
384
385__BIONIC_FORTIFY_INLINE
386__printflike(2, 0)
387int vsprintf(char *dest, const char *format, __va_list ap)
388{
389    return __builtin___vsprintf_chk(dest, 0, __bos(dest), format, ap);
390}
391
392#if defined(__clang__)
393  #if !defined(snprintf)
394    #define __wrap_snprintf(dest, size, ...) __builtin___snprintf_chk(dest, size, 0, __bos(dest), __VA_ARGS__)
395    #define snprintf(...) __wrap_snprintf(__VA_ARGS__)
396  #endif
397#else
398__BIONIC_FORTIFY_INLINE
399__printflike(3, 4)
400int snprintf(char *dest, size_t size, const char *format, ...)
401{
402    return __builtin___snprintf_chk(dest, size, 0,
403        __bos(dest), format, __builtin_va_arg_pack());
404}
405#endif
406
407#if defined(__clang__)
408  #if !defined(sprintf)
409    #define __wrap_sprintf(dest, ...) __builtin___sprintf_chk(dest, 0, __bos(dest), __VA_ARGS__)
410    #define sprintf(...) __wrap_sprintf(__VA_ARGS__)
411  #endif
412#else
413__BIONIC_FORTIFY_INLINE
414__printflike(2, 3)
415int sprintf(char *dest, const char *format, ...)
416{
417    return __builtin___sprintf_chk(dest, 0,
418        __bos(dest), format, __builtin_va_arg_pack());
419}
420#endif
421
422#if !defined(__clang__)
423
424__BIONIC_FORTIFY_INLINE
425char *fgets(char* dest, int size, FILE* stream) {
426    size_t bos = __bos(dest);
427
428    // Compiler can prove, at compile time, that the passed in size
429    // is always negative. Force a compiler error.
430    if (__builtin_constant_p(size) && (size < 0)) {
431        __fgets_too_small_error();
432    }
433
434    // Compiler doesn't know destination size. Don't call __fgets_chk
435    if (bos == __BIONIC_FORTIFY_UNKNOWN_SIZE) {
436        return __fgets_real(dest, size, stream);
437    }
438
439    // Compiler can prove, at compile time, that the passed in size
440    // is always <= the actual object size. Don't call __fgets_chk
441    if (__builtin_constant_p(size) && (size <= (int) bos)) {
442        return __fgets_real(dest, size, stream);
443    }
444
445    // Compiler can prove, at compile time, that the passed in size
446    // is always > the actual object size. Force a compiler error.
447    if (__builtin_constant_p(size) && (size > (int) bos)) {
448        __fgets_too_big_error();
449    }
450
451    return __fgets_chk(dest, size, stream, bos);
452}
453
454#endif /* !defined(__clang__) */
455
456#endif /* defined(__BIONIC_FORTIFY) */
457
458__END_DECLS
459
460#endif /* _STDIO_H_ */
461