C语言：文件复制

文本文件复制：

#include<stdio.h>int main()
{FILE* pFile1 = NULL;FILE* pFile2 = NULL;fopen_s(&pFile1,"D:\\11111.txt","r");fopen_s(&pFile2,"D:\\222.txt", "w");char c;while((c=fgetc(pFile1))!=EOF){fputc(c,pFile2);}fclose(pFile1);fclose(pFile2);return 0;
}

二进制文件复制：

#include<stdio.h>int main()
{FILE* pfile1 = NULL;FILE* pfile2 = NULL;fopen_s(&pfile1, "C:\\Users\\ljw\\Desktop\\WIN_20231103_17_32_35_Pro.jpg", "rb");//一张图片fopen_s(&pfile2, "d:\\abc.jpg", "wb");char buf[1024];while (fread(buf, 1, 1024, pfile1) > 0)//返回值>0代表读取成功{fwrite(buf, 1, 1024, pfile2);}fclose(pfile1);fclose(pfile2);return 0;
}

但在二进制文件复制这里我们会发现一个问题：那就是复制过来文件大小的大于原文件的大小。

#include<stdio.h>int main()
{FILE* pfile1 = NULL;FILE* pfile2 = NULL;fopen_s(&pfile1, "C:\\Users\\ljw\\Desktop\\WIN_20231103_17_32_35_Pro.jpg", "rb");fopen_s(&pfile2, "d:\\abc.jpg", "wb");char buf[1024];size_t nread,nwrite;while ((nread=fread(buf, 1, 1024, pfile1)) > 0){nwrite=fwrite(buf, 1, 1024, pfile2);printf("%d %d\n", nread, nwrite);//发现最后一次读取不足1024，但写入仍为1024，因此造成//要解决此问题只需将nwrite=fwrite(buf, 1, 1024, pfile2);中的1024改为nread即可}fclose(pfile1);fclose(pfile2);return 0;
}