11:27 2001-10-18 create by frankzhou

1.往Com1口写东西：
-> fp=fopen("/tyCo/0","w")
-> fprintf(fp,"what you want to write")
-> fclose(fp)

2.从Com1口读东西：
-> fp=fopen("tyCo/0","r")
-> var=malloc(100)
-> fread(var,1,50,fp)
...等待输入
-> fclose(fp)
-> printf var