C得到檔案的大小

先用fopen打開檔案,然後把檔案指針指向檔案尾.

再用ftell獲得檔案指針目前位置(即檔案長度).

源代碼：

#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); //定位到檔案末

nfilelen = ftell(fp); //檔案長度

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

可以用 stat （win 下 _stat）函數直接得檔案尺寸。

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檔案的大小

2.标準c獲得檔案大小的5種方法

(注意："__file__"指的是目前檔案，你可以改為有效路徑的目标檔案，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());