文件cp功能

#include<stdio.h>
#include<unistd.h>
#include<fcntl.h>
#include<string.h>

int main(int argc,char *argv[])
{
    int src_ret,des_ret;
    char buf[]={};
    int src_fd,des_fd;

    //判断输入的参数的个数
    if(argc<)
    {
        printf("please input src file and det file\n");
        return -;
    }

    //打开源文件
    src_fd = open(argv[],O_RDONLY);
    if(src_fd<)
    {
        printf("open src file %s is fiales\n",argv[]);
        return -;
    }
    printf("open src file %s is sucess. fd = %d\n",argv[],src_fd);

    //打开目的文件
    des_fd = open(argv[],O_CREAT | O_WRONLY,);
    if(des_fd<)
    {
        printf("open det file %s is fiales\n",argv[]);
        return -;
    }
    printf("open det file %s is sucess. wr_fd = %d\n",argv[],des_fd);

    //将源文件拷贝到目的文件中
    while(src_ret = read(src_fd,buf,))
    {
        if(feeor(src_ret:))
        {
            exit();
        }
        des_ret =  write(des_fd,buf,src_ret);
    }

    close(src_fd);
    close(des_fd);
    return ;
}