3.16作业

#1、通用文件copy工具实现
# file1=input('源文件路径>>: ').strip()
# file2=input('源文件路径>>: ').strip()
# with open(r'{}'.format(file1),mode='rb') as f1,\
#     open(r'{}'.format(file2),mode='wb') as f2:
#     for line in f1:
#         f2.write(line)


#2、基于seek控制指针移动，测试r+、w+、a+模式下的读写内容
# with open('d.txt',mode='r+',encoding='utf-8') as f:
#     print(f.read())
#     f.seek(9,0)
#     print(f.tell())
#     f.write("11")   #写入两个字节
#     f.seek(9, 0)    #回到写入前
#     print(f.read())  #读出写入内容

# with open('d.txt',mode='w+',encoding='utf-8') as f:
#     print(f.read())
#     f.seek(9,0)
#     print(f.tell())
#     res=f.write("11")
#     print(f.read())    #从11后面开始读不到内容

# with open('d.txt',mode='a+',encoding='utf-8') as f:
#     print(f.read())     #读不出内容
#     print(f.tell())    #指针在末尾的9
#     f.write("11")   #写入两个字节
#     f.seek(9, 0)    #回到写入前
#     print(f.read())  #读出写入内容



#3、tail -f access.log程序实现
cmd=input("请输入信息:")
with open('db.txt',mode='a+',encoding='utf-8')as f:
    f.write(cmd)
    f.seek(0,0)
    print(f.read())