参考韦东山老师教程:https://www.bilibili.com/video/BV1kk4y117Tu?p=12
1. 通过read方式copy文件
copy文件代码:
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
/*
* ./copy 1.txt 2.txt
* argc = 3
* argv[0] = "./copy"
* argv[1] = "1.txt"
* argv[2] = "2.txt"
*/
int main(int argc, char **argv)
{
int fd_old, fd_new;
char buf[1024];
int len;
/* 1. 判断参数 */
if (argc != 3)
{
printf("Usage: %s <old-file> <new-file>\n", argv[0]);
return -1;
}
/* 2. 打开老文件 */
fd_old = open(argv[1], O_RDONLY);
if (fd_old == -1)
{
printf("can not open file %s\n", argv[1]);
return -1;