C++获得二进制文件大小和判断文件是否达到末尾

一 获得二进制文件的大小

1 代码

#include 
#include 
using namespace std;

    
const char * filename = "afile.dat";
    
int main() {
    long l, m;
    ifstream file(filename, ios::in | ios::binary);
    l = file.tellg();
    file.seekg(0, ios::end);
    m = file.tellg();
    file.close();
    cout << "size of " << filename;
    cout << " is " << (m - l) << " bytes.\n";
    return 0;
}

2 运行

[root@localhost test]# g++ test.cpp -o test
[root@localhost test]# ./test
size of afile.dat is 9 bytes.
m is 9
l is 0

二 判断文件是否达到末尾

1 代码

#include 
#include 
using namespace std;

#include 
    
int main() {
    char buffer[256];
    ifstream examplefile("afile.dat");
    if (!examplefile.is_open())
    { cout << "Error opening file"; exit(1); }
    while (!examplefile.eof()) {    //判断文件是否达到末尾
        examplefile.getline(buffer, 100);
        cout << buffer << endl;
    }
    return 0;
}

2 运行

[root@localhost test]# g++ test.cpp -o test
[root@localhost test]# ./test
cakin
33