C得到文件的大小

先用fopen打开文件,然后把文件指针指向文件尾.

再用ftell获得文件指针当前位置(即文件长度).

源代码：

#include "stdafx.h"

#include <stdio.h>

#include <iostream>

using namespace std;

int main()

{

FILE* fp = NULL;

int nFileLen = 0;

fp = fopen("c:/Test.txt", "rb");

if (fp == NULL)

cout << "can't open file" << endl;

return 0;

}

fseek(fp,0,SEEK_END); //定位到文件末

nFileLen = ftell(fp); //文件长度

cout << "file len = " << nFileLen << endl;

可以用 stat （win 下 _stat）函数直接得文件尺寸。

man 2 stat

1.MFC中的方法：(C++)

CFileStatus status;

CFile::GetStatus("D:\\test.txt",status);

long lSizeOfFile;

lSizeOfFile = status.m_size;

lSizeOfFile的值就是D:\\test.txt文件的大小

2.标准C获得文件大小的5种方法

(注意："__FILE__"指的是当前文件，你可以改为有效路径的目标文件，比如"D:\\test.txt"）

struct stat {

dev_t st_dev; /* ID of device containing file */

ino_t st_ino; /* inode number */

mode_t st_mode; /* protection */

nlink_t st_nlink; /* number of hard links */

uid_t st_uid; /* user ID of owner */

gid_t st_gid; /* group ID of owner */

dev_t st_rdev; /* device ID (if special file) */

off_t st_size; /* total size, in bytes */

blksize_t st_blksize; /* blocksize for filesystem I/O */

blkcnt_t st_blocks; /* number of blocks allocated */

time_t st_atime; /* time of last access */

time_t st_mtime; /* time of last modification */

time_t st_ctime; /* time of last status change */

#include "stdio.h"

#include <sys/stat.h>

#include <io.h>

#include <FCNTL.H>

int getfilesize()

int iresult;

struct _stat buf;

iresult = _stat(__FILE__,&buf);

if(iresult == 0)

return buf.st_size;

return NULL;

int getfilesize01()

int fp;

fp=_open(__FILE__,_O_RDONLY);

if(fp==-1)

return _filelength(fp);

//return NULL;

int getfilesize02()

return _lseek(fp,0,SEEK_END);

int getfilesize03()

int getfilesize04()

FILE *fp;

if((fp=fopen(__FILE__,"r"))==NULL)

fseek(fp,0,SEEK_END);

return ftell(fp); //return NULL;

int getfilesize05()

char str[1];

if((fp=fopen(__FILE__,"rb"))==NULL)

for(int i = 0;!feof(fp);i++)

fread(&str,1,1,fp);

return i - 1; //return NULL;

int main(int argc, char* argv[])

printf("getfilesize()=%d\n",getfilesize());

printf("getfilesize01()=%d\n",getfilesize01());

printf("getfilesize02()=%d\n",getfilesize02());

printf("getfilesize03()=%d\n",getfilesize03());

printf("getfilesize04()=%d\n",getfilesize04());

printf("getfilesize05()=%d\n",getfilesize05());