Система: Linux

Язык: C

Компилятор: gcc

 

Проблема состоит в том, что для файлов по размеру больше 2 гб функция stat() выдает всякую ерунду вплане размера файла. Проблема эта проявляется не везде. Например на 64 битной системе все работает корректно, а на другой, которая является 32 битной возникает эта проблема. Как я понял возвращаемый фуекцией размер имеет тип long, и судя по всему диапазон типа long для 64 битной и 32 битной систем различаются, поэтому в последней из них происходит переполнение.

Искал решение, нашел функцию stat64(), которая вроде как возвращает размер типа long long, но простейший пример с ее использованием отказывается компилиться

#include <sys/stat.h>
#include<stdio.h>
long long GetFileSize(char filename[]) 
{ 
        struct stat64 info; 
        stat64(filename, &info);
        return info.st_size; 
}
main()
{
    printf("%lld", GetFileSize("sta"));
}

 

Такая ошибка:

test.c:5: error: storage size of ‘info’ isn’t known

 

Что посоветуете?

try this

 

http://unix.derkeiler.com/Newsgroups/comp....5/msg00401.html

Проверьте, действительно ли у вас описана структура struct stat64 в файле sys/stat.h

 

try this

 

http://unix.derkeiler.com/Newsgroups/comp....5/msg00401.html

 

-D_FILE_OFFSET_BITS=64 делает так, что в структуре struct stat размеры длинные и вместо stat64() можно использовать просто stat()

http://sources.redhat.com/ml/libc-alpha/20...6/msg00041.html

 

try this http://unix.derkeiler.com/Newsgroups/comp....5/msg00401.html

 

Сработало, спасибо. Одно неудобно - этот ключик теперь нужно помнить для того чтобы скомпилить :)

 

Проверьте, действительно ли у вас описана структура struct stat64 в файле sys/stat.h

 

Могу сказать одно - stat64 в файле /usr/include/sys/stat.h упоминается.

Но чегото видать не хватает, а жаль.

 

stat.h:

/* Copyright © 1991, 1992, 1995-2004, 2005, 2006, 2007

  Free Software Foundation, Inc.

  This file is part of the GNU C Library.



  The GNU C Library is free software; you can redistribute it and/or

  modify it under the terms of the GNU Lesser General Public

  License as published by the Free Software Foundation; either

  version 2.1 of the License, or (at your option) any later version.



  The GNU C Library is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  Lesser General Public License for more details.



  You should have received a copy of the GNU Lesser General Public

  License along with the GNU C Library; if not, write to the Free

  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

  02111-1307 USA.  */



/*

*	POSIX Standard: 5.6 File Characteristics	

*/



#ifndef	_SYS_STAT_H

#define	_SYS_STAT_H	1



#include 



#include 		/* For __mode_t and __dev_t.  */



#if defined __USE_XOPEN || defined __USE_XOPEN2K || defined __USE_MISC \

        || defined __USE_ATFILE

# if defined __USE_XOPEN || defined __USE_XOPEN2K

#  define __need_time_t

# endif

# if defined __USE_MISC || defined __USE_ATFILE

#  define __need_timespec

# endif

# include 		/* For time_t resp. timespec.  */

#endif



#if defined __USE_XOPEN || defined __USE_XOPEN2K

/* The Single Unix specification says that some more types are

  available here.  */

# ifndef __dev_t_defined

typedef __dev_t dev_t;

#  define __dev_t_defined

# endif



# ifndef __gid_t_defined

typedef __gid_t gid_t;

#  define __gid_t_defined

# endif



# ifndef __ino_t_defined

#  ifndef __USE_FILE_OFFSET64

typedef __ino_t ino_t;

#  else

typedef __ino64_t ino_t;

#  endif

#  define __ino_t_defined

# endif



# ifndef __mode_t_defined

typedef __mode_t mode_t;

#  define __mode_t_defined

# endif



# ifndef __nlink_t_defined

typedef __nlink_t nlink_t;

#  define __nlink_t_defined

# endif



# ifndef __off_t_defined

#  ifndef __USE_FILE_OFFSET64

typedef __off_t off_t;

#  else

typedef __off64_t off_t;

#  endif

#  define __off_t_defined

# endif



# ifndef __uid_t_defined

typedef __uid_t uid_t;

#  define __uid_t_defined

# endif

#endif	/* X/Open */



#ifdef __USE_UNIX98

# ifndef __blkcnt_t_defined

#  ifndef __USE_FILE_OFFSET64

typedef __blkcnt_t blkcnt_t;

#  else

typedef __blkcnt64_t blkcnt_t;

#  endif

#  define __blkcnt_t_defined

# endif



# ifndef __blksize_t_defined

typedef __blksize_t blksize_t;

#  define __blksize_t_defined

# endif

#endif	/* Unix98 */



__BEGIN_DECLS



#include 



#if defined __USE_BSD || defined __USE_MISC || defined __USE_XOPEN

# define S_IFMT		__S_IFMT

# define S_IFDIR	__S_IFDIR

# define S_IFCHR	__S_IFCHR

# define S_IFBLK	__S_IFBLK

# define S_IFREG	__S_IFREG

# ifdef __S_IFIFO

#  define S_IFIFO	__S_IFIFO

# endif

# ifdef __S_IFLNK

#  define S_IFLNK	__S_IFLNK

# endif

# if (defined __USE_BSD || defined __USE_MISC || defined __USE_UNIX98) \

    && defined __S_IFSOCK

#  define S_IFSOCK	__S_IFSOCK

# endif

#endif



/* Test macros for file types.	*/



#define	__S_ISTYPE(mode, mask)	(((mode) & __S_IFMT) == (mask))



#define	S_ISDIR(mode)	 __S_ISTYPE((mode), __S_IFDIR)

#define	S_ISCHR(mode)	 __S_ISTYPE((mode), __S_IFCHR)

#define	S_ISBLK(mode)	 __S_ISTYPE((mode), __S_IFBLK)

#define	S_ISREG(mode)	 __S_ISTYPE((mode), __S_IFREG)

#ifdef __S_IFIFO

# define S_ISFIFO(mode)	 __S_ISTYPE((mode), __S_IFIFO)

#endif

#ifdef __S_IFLNK

# define S_ISLNK(mode)	 __S_ISTYPE((mode), __S_IFLNK)

#endif



#if defined __USE_BSD && !defined __S_IFLNK

# define S_ISLNK(mode)  0

#endif



#if (defined __USE_BSD || defined __USE_UNIX98) \

   && defined __S_IFSOCK

# define S_ISSOCK(mode) __S_ISTYPE((mode), __S_IFSOCK)

#endif



/* These are from POSIX.1b.  If the objects are not implemented using separate

  distinct file types, the macros always will evaluate to zero.  Unlike the

  other S_* macros the following three take a pointer to a `struct stat'

  object as the argument.  */

#ifdef	__USE_POSIX199309

# define S_TYPEISMQ(buf) __S_TYPEISMQ(buf)

# define S_TYPEISSEM(buf) __S_TYPEISSEM(buf)

# define S_TYPEISSHM(buf) __S_TYPEISSHM(buf)

#endif





/* Protection bits.  */



#define	S_ISUID __S_ISUID	/* Set user ID on execution.  */

#define	S_ISGID	__S_ISGID	/* Set group ID on execution.  */



#if defined __USE_BSD || defined __USE_MISC || defined __USE_XOPEN

/* Save swapped text after use (sticky bit).  This is pretty well obsolete.  */

# define S_ISVTX	__S_ISVTX

#endif



#define	S_IRUSR	__S_IREAD	/* Read by owner.  */

#define	S_IWUSR	__S_IWRITE	/* Write by owner.  */

#define	S_IXUSR	__S_IEXEC	/* Execute by owner.  */

/* Read, write, and execute by owner.  */

#define	S_IRWXU	(__S_IREAD|__S_IWRITE|__S_IEXEC)



#if defined __USE_MISC && defined __USE_BSD

# define S_IREAD	S_IRUSR

# define S_IWRITE	S_IWUSR

# define S_IEXEC	S_IXUSR

#endif



#define	S_IRGRP	(S_IRUSR >> 3)	/* Read by group.  */

#define	S_IWGRP	(S_IWUSR >> 3)	/* Write by group.  */

#define	S_IXGRP	(S_IXUSR >> 3)	/* Execute by group.  */

/* Read, write, and execute by group.  */

#define	S_IRWXG	(S_IRWXU >> 3)



#define	S_IROTH	(S_IRGRP >> 3)	/* Read by others.  */

#define	S_IWOTH	(S_IWGRP >> 3)	/* Write by others.  */

#define	S_IXOTH	(S_IXGRP >> 3)	/* Execute by others.  */

/* Read, write, and execute by others.  */

#define	S_IRWXO	(S_IRWXG >> 3)





#ifdef	__USE_BSD

/* Macros for common mode bit masks.  */

# define ACCESSPERMS (S_IRWXU|S_IRWXG|S_IRWXO) /* 0777 */

# define ALLPERMS (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO)/* 07777 */

# define DEFFILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)/* 0666*/



# define S_BLKSIZE	512	/* Block size for `st_blocks'.  */

#endif





#ifndef __USE_FILE_OFFSET64

/* Get file attributes for FILE and put them in BUF.  */

extern int stat (__const char *__restrict __file,

	 struct stat *__restrict __buf) __THROW __nonnull ((1, 2));



/* Get file attributes for the file, device, pipe, or socket

  that file descriptor FD is open on and put them in BUF.  */

extern int fstat (int __fd, struct stat *__buf) __THROW __nonnull ((2));

#else

# ifdef __REDIRECT_NTH

extern int __REDIRECT_NTH (stat, (__const char *__restrict __file,

			  struct stat *__restrict __buf), stat64)

    __nonnull ((1, 2));

extern int __REDIRECT_NTH (fstat, (int __fd, struct stat *__buf), fstat64)

    __nonnull ((2));

# else

#  define stat stat64

#  define fstat fstat64

# endif

#endif

#ifdef __USE_LARGEFILE64

extern int stat64 (__const char *__restrict __file,

	   struct stat64 *__restrict __buf) __THROW __nonnull ((1, 2));

extern int fstat64 (int __fd, struct stat64 *__buf) __THROW __nonnull ((2));

#endif



#ifdef __USE_ATFILE

/* Similar to stat, get the attributes for FILE and put them in BUF.

  Relative path names are interpreted relative to FD unless FD is

  AT_FDCWD.  */

# ifndef __USE_FILE_OFFSET64

extern int fstatat (int __fd, __const char *__restrict __file,

	    struct stat *__restrict __buf, int __flag)

    __THROW __nonnull ((2, 3));

# else

#  ifdef __REDIRECT_NTH

extern int __REDIRECT_NTH (fstatat, (int __fd, __const char *__restrict __file,

			     struct stat *__restrict __buf,

			     int __flag),

		   fstatat64) __nonnull ((2, 3));

#  else

#   define fstatat fstatat64

#  endif

# endif



extern int fstatat64 (int __fd, __const char *__restrict __file,

	      struct stat64 *__restrict __buf, int __flag)

    __THROW __nonnull ((2, 3));

#endif



#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED

# ifndef __USE_FILE_OFFSET64

/* Get file attributes about FILE and put them in BUF.

  If FILE is a symbolic link, do not follow it.  */

extern int lstat (__const char *__restrict __file,

	  struct stat *__restrict __buf) __THROW __nonnull ((1, 2));

# else

#  ifdef __REDIRECT_NTH

extern int __REDIRECT_NTH (lstat,

		   (__const char *__restrict __file,

		    struct stat *__restrict __buf), lstat64)

    __nonnull ((1, 2));

#  else

#   define lstat lstat64

#  endif

# endif

# ifdef __USE_LARGEFILE64

extern int lstat64 (__const char *__restrict __file,

	    struct stat64 *__restrict __buf)

    __THROW __nonnull ((1, 2));

# endif

#endif



/* Set file access permissions for FILE to MODE.

  If FILE is a symbolic link, this affects its target instead.  */

extern int chmod (__const char *__file, __mode_t __mode)

    __THROW __nonnull ((1));



#ifdef __USE_BSD

/* Set file access permissions for FILE to MODE.

  If FILE is a symbolic link, this affects the link itself

  rather than its target.  */

extern int lchmod (__const char *__file, __mode_t __mode)

    __THROW __nonnull ((1));

#endif



/* Set file access permissions of the file FD is open on to MODE.  */

#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED

extern int fchmod (int __fd, __mode_t __mode) __THROW;

#endif



#ifdef __USE_ATFILE

/* Set file access permissions of FILE relative to

  the directory FD is open on.  */

extern int fchmodat (int __fd, __const char *__file, __mode_t mode, int __flag)

    __THROW __nonnull ((2)) __wur;

#endif /* Use ATFILE.  */







/* Set the file creation mask of the current process to MASK,

  and return the old creation mask.  */

extern __mode_t umask (__mode_t __mask) __THROW;



#ifdef	__USE_GNU

/* Get the current `umask' value without changing it.

  This function is only available under the GNU Hurd.  */

extern __mode_t getumask (void) __THROW;

#endif



/* Create a new directory named PATH, with permission bits MODE.  */

extern int mkdir (__const char *__path, __mode_t __mode)

    __THROW __nonnull ((1));



#ifdef __USE_ATFILE

/* Like mkdir, create a new directory with permission bits MODE.  But

  interpret relative PATH names relative to the directory associated

  with FD.  */

extern int mkdirat (int __fd, __const char *__path, __mode_t __mode)

    __THROW __nonnull ((2));

#endif



/* Create a device file named PATH, with permission and special bits MODE

  and device number DEV (which can be constructed from major and minor

  device numbers with the `makedev' macro above).  */

#if defined __USE_MISC || defined __USE_BSD || defined __USE_XOPEN_EXTENDED

extern int mknod (__const char *__path, __mode_t __mode, __dev_t __dev)

    __THROW __nonnull ((1));

#endif



#ifdef __USE_ATFILE

/* Like mknod, create a new device file with permission bits MODE and

  device number DEV.  But interpret relative PATH names relative to

  the directory associated with FD.  */

extern int mknodat (int __fd, __const char *__path, __mode_t __mode,

	    __dev_t __dev) __THROW __nonnull ((2));

#endif





/* Create a new FIFO named PATH, with permission bits MODE.  */

extern int mkfifo (__const char *__path, __mode_t __mode)

    __THROW __nonnull ((1));



#ifdef __USE_ATFILE

/* Like mkfifo, create a new FIFO with permission bits MODE.  But

  interpret relative PATH names relative to the directory associated

  with FD.  */

extern int mkfifoat (int __fd, __const char *__path, __mode_t __mode)

    __THROW __nonnull ((2));

#endif



#ifdef __USE_ATFILE

/* Set file access and modification times relative to directory file

  descriptor.  */

extern int utimensat (int __fd, __const char *__path,

	      __const struct timespec __times[2],

	      int __flags)

    __THROW __nonnull ((2));

#endif



#ifdef __USE_GNU

/* XXX This will change to the macro for the next 2008 POSIX revision.  */

/* Set file access and modification times of the file associated with FD.  */

extern int futimens (int __fd, __const struct timespec __times[2]) __THROW;

#endif



/* To allow the `struct stat' structure and the file type `mode_t'

  bits to vary without changing shared library major version number,

  the `stat' family of functions and `mknod' are in fact inline

  wrappers around calls to `xstat', `fxstat', `lxstat', and `xmknod',

  which all take a leading version-number argument designating the

  data structure and bits used.   defines _STAT_VER with

  the version number corresponding to `struct stat' as defined in

  that file; and _MKNOD_VER with the version number corresponding to

  the S_IF* macros defined therein.  It is arranged that when not

  inlined these function are always statically linked; that way a

  dynamically-linked executable always encodes the version number

  corresponding to the data structures it uses, so the `x' functions

  in the shared library can adapt without needing to recompile all

  callers.  */



#ifndef _STAT_VER

# define _STAT_VER	0

#endif

#ifndef _MKNOD_VER

# define _MKNOD_VER	0

#endif



/* Wrappers for stat and mknod system calls.  */

#ifndef __USE_FILE_OFFSET64

extern int __fxstat (int __ver, int __fildes, struct stat *__stat_buf)

    __THROW __nonnull ((3));

extern int __xstat (int __ver, __const char *__filename,

	    struct stat *__stat_buf) __THROW __nonnull ((2, 3));

extern int __lxstat (int __ver, __const char *__filename,

	     struct stat *__stat_buf) __THROW __nonnull ((2, 3));

extern int __fxstatat (int __ver, int __fildes, __const char *__filename,

	       struct stat *__stat_buf, int __flag)

    __THROW __nonnull ((3, 4));

#else

# ifdef __REDIRECT_NTH

extern int __REDIRECT_NTH (__fxstat, (int __ver, int __fildes,

			      struct stat *__stat_buf), __fxstat64)

    __nonnull ((3));

extern int __REDIRECT_NTH (__xstat, (int __ver, __const char *__filename,

			     struct stat *__stat_buf), __xstat64)

    __nonnull ((2, 3));

extern int __REDIRECT_NTH (__lxstat, (int __ver, __const char *__filename,

			      struct stat *__stat_buf), __lxstat64)

    __nonnull ((2, 3));

extern int __REDIRECT_NTH (__fxstatat, (int __ver, int __fildes,

				__const char *__filename,

				struct stat *__stat_buf, int __flag),

		   __fxstatat64) __nonnull ((3, 4));



# else

#  define __fxstat __fxstat64

#  define __xstat __xstat64

#  define __lxstat __lxstat64

# endif

#endif



#ifdef __USE_LARGEFILE64

extern int __fxstat64 (int __ver, int __fildes, struct stat64 *__stat_buf)

    __THROW __nonnull ((3));

extern int __xstat64 (int __ver, __const char *__filename,

	      struct stat64 *__stat_buf) __THROW __nonnull ((2, 3));

extern int __lxstat64 (int __ver, __const char *__filename,

	       struct stat64 *__stat_buf) __THROW __nonnull ((2, 3));

extern int __fxstatat64 (int __ver, int __fildes, __const char *__filename,

		 struct stat64 *__stat_buf, int __flag)

    __THROW __nonnull ((3, 4));

#endif

extern int __xmknod (int __ver, __const char *__path, __mode_t __mode,

	     __dev_t *__dev) __THROW __nonnull ((2, 4));



extern int __xmknodat (int __ver, int __fd, __const char *__path,

	       __mode_t __mode, __dev_t *__dev)

    __THROW __nonnull ((3, 5));



#if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES

/* Inlined versions of the real stat and mknod functions.  */



__extern_inline int

__NTH (stat (__const char *__path, struct stat *__statbuf))

{

 return __xstat (_STAT_VER, __path, __statbuf);

}



# if defined __USE_BSD || defined __USE_XOPEN_EXTENDED

__extern_inline int

__NTH (lstat (__const char *__path, struct stat *__statbuf))

{

 return __lxstat (_STAT_VER, __path, __statbuf);

}

# endif



__extern_inline int

__NTH (fstat (int __fd, struct stat *__statbuf))

{

 return __fxstat (_STAT_VER, __fd, __statbuf);

}



# ifdef __USE_ATFILE

__extern_inline int

__NTH (fstatat (int __fd, __const char *__filename, struct stat *__statbuf,

	int __flag))

{

 return __fxstatat (_STAT_VER, __fd, __filename, __statbuf, __flag);

}

# endif



# if defined __USE_MISC || defined __USE_BSD

__extern_inline int

__NTH (mknod (__const char *__path, __mode_t __mode, __dev_t __dev))

{

 return __xmknod (_MKNOD_VER, __path, __mode, &__dev);

}

# endif



# ifdef __USE_ATFILE

__extern_inline int

__NTH (mknodat (int __fd, __const char *__path, __mode_t __mode,

	__dev_t __dev))

{

 return __xmknodat (_MKNOD_VER, __fd, __path, __mode, &__dev);

}

# endif



# if defined __USE_LARGEFILE64 \

 && (! defined __USE_FILE_OFFSET64 \

     || (defined __REDIRECT_NTH && defined __OPTIMIZE__))

__extern_inline int

__NTH (stat64 (__const char *__path, struct stat64 *__statbuf))

{

 return __xstat64 (_STAT_VER, __path, __statbuf);

}



#  if defined __USE_BSD || defined __USE_XOPEN_EXTENDED

__extern_inline int

__NTH (lstat64 (__const char *__path, struct stat64 *__statbuf))

{

 return __lxstat64 (_STAT_VER, __path, __statbuf);

}

#  endif



__extern_inline int

__NTH (fstat64 (int __fd, struct stat64 *__statbuf))

{

 return __fxstat64 (_STAT_VER, __fd, __statbuf);

}



#  ifdef __USE_GNU

__extern_inline int

__NTH (fstatat64 (int __fd, __const char *__filename, struct stat64 *__statbuf,

	  int __flag))

{

 return __fxstatat64 (_STAT_VER, __fd, __filename, __statbuf, __flag);

}

#  endif



# endif



#endif



__END_DECLS





#endif /* sys/stat.h  */

Проверьте, действительно ли у вас описана структура struct stat64 в файле sys/stat.h

 

Могу сказать одно - stat64 в файле /usr/include/sys/stat.h упоминается.

Но чегото видать не хватает, а жаль.

 

Что-то в самом файле, который вы привели нужная структура не описана, а из инклудов исчезли имена файлов, так что понять где эта структура должна жить - не судьба.

 

Чтобы не помнить ключик - можете вписать первой строчкой в программе #define _FILE_OFFSET_BITS 64

Чтобы не помнить ключик - можете вписать первой строчкой в программе #define _FILE_OFFSET_BITS 64

Пишу это первой строчкой и компилю, как обычно без лишних ключей значит.

Спасибо, так гораздо удобнее :)

struct stat64 определена в файле bits/stat.h, включаемом в файле sys/stat.h.

И определена она так:

#ifdef __USE_LARGEFILE64
struct stat64
  {
    __dev_t st_dev;                     /* Device.  */
    unsigned int __pad1;

    __ino_t __st_ino;                   /* 32bit file serial number.    */
    __mode_t st_mode;                   /* File mode.  */
    __nlink_t st_nlink;                 /* Link count.  */
    __uid_t st_uid;                     /* User ID of the file's owner. */
    __gid_t st_gid;                     /* Group ID of the file's group.*/
    __dev_t st_rdev;                    /* Device number, if device.  */
    unsigned int __pad2;
    __off64_t st_size;                  /* Size of file, in bytes.  */
    __blksize_t st_blksize;             /* Optimal block size for I/O.  */

    __blkcnt64_t st_blocks;             /* Number 512-byte blocks allocated. */
    __time_t st_atime;                  /* Time of last access.  */
    unsigned long int __unused1;
    __time_t st_mtime;                  /* Time of last modification.  */
    unsigned long int __unused2;
    __time_t st_ctime;                  /* Time of last status change.  */
    unsigned long int __unused3;
    __ino64_t st_ino;                   /* File serial number.          */
  };
#endif

 

Откуда следует, что для того, чтобы ее использовать, надо определить __USE_LARGEFILE64.

struct stat64 определена в файле bits/stat.h, включаемом в файле sys/stat.h.

И определена она так:

 

{...Skipped...}

 

Откуда следует, что для того, чтобы ее использовать, надо определить __USE_LARGEFILE64.

 

Ну вот, значит можно писать #define __USE_LARGEFILE64 ... Хотя с предыдущим define и обычным stat'ом мне как-то больше нравится

Правильнее все-таки определять _FILE_OFFSET_BITS, это портабельный способ, а __USE_LARGEFILE64 -- внутренности глибси, в которые лучше не лезть.