C++ 文件复制

 1 #include<iostream>
 2 #include<fstream>
 3 
 4 void copy(char* src, char* dst);
 5 int main()
 6 {
 7     using namespace std;
 8     char src[50] = "E:/test/jdk-8u121-windows-x64.exe";
 9     char dst[50] = "E:\\test\\jdk-8u121-windows-x64_bak.exe";
10     copy(src, dst);
11     
12     return 0;
13 }
14 
15 void copy(char* src, char* dst)
16 {
17     using namespace std;
18     ifstream in(src,ios::binary);
19     ofstream out(dst,ios::binary);
20     if (!in.is_open()) {
21         cout << "error open file " << src << endl;
22         exit(EXIT_FAILURE);
23     }
24     if (!out.is_open()) {
25         cout << "error open file " << dst << endl;
26         exit(EXIT_FAILURE);
27     }
28     if (src == dst) {
29         cout << "the src file can't be same with dst file" << endl;
30         exit(EXIT_FAILURE);
31     }
32     char buf[2048];
33     long long totalBytes = 0;
34     while(in)
35     {
36         //read从in流中读取2048字节，放入buf数组中，同时文件指针向后移动2048字节
37         //若不足2048字节遇到文件结尾，则以实际提取字节读取。
38         in.read(buf, 2048);    
39         //gcount()用来提取读取的字节数，write将buf中的内容写入out流。
40         out.write(buf, in.gcount());    
41         totalBytes += in.gcount();
42     }
43     in.close();
44     out.close();
45 }