系统函数学习

#include
#include
#include
#include


void main(int argc,char **argv)
{
    int fd_s;
    int fd_t;
    char buf[512];
    int count =0;
    
    /*打开文件*/
    fd_s = open(argv[1],O_RDONLY);
    fd_t = open(argv[2],O_RDWR|O_CREAT,0666);
    
    /*读取文件,写入文件*/
    while((count = read(fd_s, buf,512) ) >0)
        write(fd_t, buf,count);
    
    close(fd_s);
    close(fd_t);
}