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#include <stdio.h>
//#include <stdlib.h>
//#include <string.h>
#include <io.h>
#include <fcntl.h>
//#include <sys/types.h>
#include <sys/stat.h>
int main(void)
{
long len;
int fh, result;
FILE *fp1 = fopen("3.txt", "w");
fputs("1234567654321", fp1);
fseek(fp1, -5, SEEK_CUR);
fputs("88", fp1);
len = ftell(fp1);
fclose(fp1);
/* Open a file */
if ((fh = _open("3.txt", _O_RDWR | _O_CREAT, _S_IREAD | _S_IWRITE)) != -1)
{
printf("File length before: %ld\n", _filelength(fh));
if ((result = _chsize(fh, len)) == 0)
printf("Size successfully changed\n");
else
printf("Problem in changing the size\n");
printf("File length after: %ld\n", _filelength(fh));
_close(fh);
}
return 0;
}
/***
*io.h - declarations for low-level file handling and I/O functions
*
* Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
* This file contains the function declarations for the low-level
* file handling and I/O functions.
*
* [Public]
*
****/
#if _MSC_VER > 1000
#pragma once
#endif
#ifndef _INC_IO
#define _INC_IO
#if !defined(_WIN32) && !defined(_MAC)
#error ERROR: Only Mac or Win32 targets supported!
#endif
#ifdef _MSC_VER
/*
* Currently, all MS C compilers for Win32 platforms default to 8 byte
* alignment.
*/
#pragma pack(push,8)
#endif /* _MSC_VER */
#ifndef _POSIX_
#ifdef __cplusplus
extern "C" {
#endif
/* Define _CRTIMP */
#ifndef _CRTIMP
#ifdef _DLL
#define _CRTIMP __declspec(dllimport)
#else /* ndef _DLL */
#define _CRTIMP
#endif /* _DLL */
#endif /* _CRTIMP */
/* Define __cdecl for non-Microsoft compilers */
#if ( !defined(_MSC_VER) && !defined(__cdecl) )
#define __cdecl
#endif
/* Define _CRTAPI1 (for compatibility with the NT SDK) */
#ifndef _CRTAPI1
#if _MSC_VER >= 800 && _M_IX86 >= 300
#define _CRTAPI1 __cdecl
#else
#define _CRTAPI1
#endif
#endif
#ifndef _MAC
#ifndef _WCHAR_T_DEFINED
typedef unsigned short wchar_t;
#define _WCHAR_T_DEFINED
#endif
#endif /* ndef _MAC */
#ifndef _TIME_T_DEFINED
typedef long time_t; /* time value */
#define _TIME_T_DEFINED /* avoid multiple def's of time_t */
#endif
#ifndef _FSIZE_T_DEFINED
typedef unsigned long _fsize_t; /* Could be 64 bits for Win32 */
#define _FSIZE_T_DEFINED
#endif
#ifndef _MAC
#ifndef _FINDDATA_T_DEFINED
struct _finddata_t {
unsigned attrib;
time_t time_create; /* -1 for FAT file systems */
time_t time_access; /* -1 for FAT file systems */
time_t time_write;
_fsize_t size;
char name[260];
};
#if _INTEGRAL_MAX_BITS >= 64
struct _finddatai64_t {
unsigned attrib;
time_t time_create; /* -1 for FAT file systems */
time_t time_access; /* -1 for FAT file systems */
time_t time_write;
__int64 size;
char name[260];
};
#endif
#define _FINDDATA_T_DEFINED
#endif
#ifndef _WFINDDATA_T_DEFINED
struct _wfinddata_t {
unsigned attrib;
time_t time_create; /* -1 for FAT file systems */
time_t time_access; /* -1 for FAT file systems */
time_t time_write;
_fsize_t size;
wchar_t name[260];
};
#if _INTEGRAL_MAX_BITS >= 64
struct _wfinddatai64_t {
unsigned attrib;
time_t time_create; /* -1 for FAT file systems */
time_t time_access; /* -1 for FAT file systems */
time_t time_write;
__int64 size;
wchar_t name[260];
};
#endif
#define _WFINDDATA_T_DEFINED
#endif
/* File attribute constants for _findfirst() */
#define _A_NORMAL 0x00 /* Normal file - No read/write restrictions */
#define _A_RDONLY 0x01 /* Read only file */
#define _A_HIDDEN 0x02 /* Hidden file */
#define _A_SYSTEM 0x04 /* System file */
#define _A_SUBDIR 0x10 /* Subdirectory */
#define _A_ARCH 0x20 /* Archive file */
#endif /* ndef _MAC */
/* function prototypes */
_CRTIMP int __cdecl _access(const char *, int);
_CRTIMP int __cdecl _chmod(const char *, int);
_CRTIMP int __cdecl _chsize(int, long);
_CRTIMP int __cdecl _close(int);
_CRTIMP int __cdecl _commit(int);
_CRTIMP int __cdecl _creat(const char *, int);
_CRTIMP int __cdecl _dup(int);
_CRTIMP int __cdecl _dup2(int, int);
_CRTIMP int __cdecl _eof(int);
_CRTIMP long __cdecl _filelength(int);
#ifndef _MAC
_CRTIMP long __cdecl _findfirst(const char *, struct _finddata_t *);
_CRTIMP int __cdecl _findnext(long, struct _finddata_t *);
_CRTIMP int __cdecl _findclose(long);
#endif /* ndef _MAC */
_CRTIMP int __cdecl _isatty(int);
_CRTIMP int __cdecl _locking(int, int, long);
_CRTIMP long __cdecl _lseek(int, long, int);
_CRTIMP char * __cdecl _mktemp(char *);
_CRTIMP int __cdecl _open(const char *, int, ...);
#ifndef _MAC
_CRTIMP int __cdecl _pipe(int *, unsigned int, int);
#endif /* ndef _MAC */
_CRTIMP int __cdecl _read(int, void *, unsigned int);
_CRTIMP int __cdecl remove(const char *);
_CRTIMP int __cdecl rename(const char *, const char *);
_CRTIMP int __cdecl _setmode(int, int);
_CRTIMP int __cdecl _sopen(const char *, int, int, ...);
_CRTIMP long __cdecl _tell(int);
_CRTIMP int __cdecl _umask(int);
_CRTIMP int __cdecl _unlink(const char *);
_CRTIMP int __cdecl _write(int, const void *, unsigned int);
#if _INTEGRAL_MAX_BITS >= 64
_CRTIMP __int64 __cdecl _filelengthi64(int);
_CRTIMP long __cdecl _findfirsti64(const char *, struct _finddatai64_t *);
_CRTIMP int __cdecl _findnexti64(long, struct _finddatai64_t *);
_CRTIMP __int64 __cdecl _lseeki64(int, __int64, int);
_CRTIMP __int64 __cdecl _telli64(int);
#endif
#ifndef _MAC
#ifndef _WIO_DEFINED
/* wide function prototypes, also declared in wchar.h */
_CRTIMP int __cdecl _waccess(const wchar_t *, int);
_CRTIMP int __cdecl _wchmod(const wchar_t *, int);
_CRTIMP int __cdecl _wcreat(const wchar_t *, int);
_CRTIMP long __cdecl _wfindfirst(const wchar_t *, struct _wfinddata_t *);
_CRTIMP int __cdecl _wfindnext(long, struct _wfinddata_t *);
_CRTIMP int __cdecl _wunlink(const wchar_t *);
_CRTIMP int __cdecl _wrename(const wchar_t *, const wchar_t *);
_CRTIMP int __cdecl _wopen(const wchar_t *, int, ...);
_CRTIMP int __cdecl _wsopen(const wchar_t *, int, int, ...);
_CRTIMP wchar_t * __cdecl _wmktemp(wchar_t *);
#if _INTEGRAL_MAX_BITS >= 64
_CRTIMP long __cdecl _wfindfirsti64(const wchar_t *, struct _wfinddatai64_t *);
_CRTIMP int __cdecl _wfindnexti64(long, struct _wfinddatai64_t *);
#endif
#define _WIO_DEFINED
#endif
#endif /* ndef _MAC */
_CRTIMP long __cdecl _get_osfhandle(int);
_CRTIMP int __cdecl _open_osfhandle(long, int);
#if !__STDC__
/* Non-ANSI names for compatibility */
_CRTIMP int __cdecl access(const char *, int);
_CRTIMP int __cdecl chmod(const char *, int);
_CRTIMP int __cdecl chsize(int, long);
_CRTIMP int __cdecl close(int);
_CRTIMP int __cdecl creat(const char *, int);
_CRTIMP int __cdecl dup(int);
_CRTIMP int __cdecl dup2(int, int);
_CRTIMP int __cdecl eof(int);
_CRTIMP long __cdecl filelength(int);
_CRTIMP int __cdecl isatty(int);
_CRTIMP int __cdecl locking(int, int, long);
_CRTIMP long __cdecl lseek(int, long, int);
_CRTIMP char * __cdecl mktemp(char *);
_CRTIMP int __cdecl open(const char *, int, ...);
_CRTIMP int __cdecl read(int, void *, unsigned int);
_CRTIMP int __cdecl setmode(int, int);
_CRTIMP int __cdecl sopen(const char *, int, int, ...);
_CRTIMP long __cdecl tell(int);
_CRTIMP int __cdecl umask(int);
_CRTIMP int __cdecl unlink(const char *);
_CRTIMP int __cdecl write(int, const void *, unsigned int);
#endif /* __STDC__ */
#ifdef __cplusplus
}
#endif
#endif /* _POSIX_ */
#ifdef _MSC_VER
#pragma pack(pop)
#endif /* _MSC_VER */
#endif /* _INC_IO */