文件IO-C实现cp命令

/*
	Linux API:read,write,open
	function:C实现CP Command
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>	// read
#include <fcntl.h>	// open

#define MAX 100

int main(int argc, char **argv)
{
	ssize_t size = -1;
	char buf[MAX] = {0};
	
	// 打开文件
	int oldFile, newFile;	
	// if (oldFile = open(fileName, O_RDONLY) < 0) 这样的写法会阻塞，为什么？
	oldFile = open(argv[1], O_RDONLY);
	if ( oldFile < 0)
	{
		perror("Error open 1");
		exit(EXIT_FAILURE);
	} else {
        printf("open %s successfully, fd:%d\n", argv[1], oldFile);
    }
	if ((newFile = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0)
	{
		perror("Error open 1");
		exit(EXIT_FAILURE);
	} else {
        printf("open %s successfully, fd:%d\n", argv[2], newFile);
    }
	
	// 循环读写文件
	do
	{
		size = read(oldFile, buf, MAX);
		write(newFile, buf, size);
		if (size <= 0) {                         // 有效数据，指定字符长度
            printf("reach the end of file end\n");
			break;
		}
	} while(size);
	
	close(oldFile);
	close(newFile);
	exit(EXIT_SUCCESS);
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.22)
message("Hello myProject")
project(myProject)
 
add_executable(myExec mainCP.c)