man手册、zip备份
3.1问题
本例要求掌握man帮助手册的使用，以及zip压缩/解压缩的操作，完成下列任务：
查阅passwd命令、/etc/passwd配置文件的手册页
使用zip打包/usr/share/doc/qemu-kvm/目录
3.2方案
zip/unzip压缩与解压缩：
制作zip压缩包：zip[-r]备份文件.zip被归档的文档...
释放zip压缩包：unzip备份文件.zip[-d目标文件夹]
3.3步骤
实现此案例需要按照如下步骤进行。
步骤一：使用man手册页获取帮助
1）查看passwd命令的手册页
[root@svr7~]#man passwd
PASSWD(1)User utilities PASSWD(1)
NAME
passwd-update user's authentication tokens
SYNOPSIS
passwd[-k][-l][-u[-f]][-d][-e][-n mindays][-x maxdays][-w
warndays][-i inactivedays][-S][--stdin][username]
DESCRIPTION
The passwd utility is used to update user's authentication token(s).
This task is achieved through calls to the Linux-PAM and Libuser API.
Essentially,it initializes itself as a"passwd"service with Linux-
PAM and utilizes configured password modules to authenticate and then
update a user's password.
....
2）查看/etc/passwd配置文件的手册页
[root@svr7~]#man 2 passwd
PASSWD(5)Linux Programmer's Manual PASSWD(5)
NAME
passwd-password file
DESCRIPTION
The/etc/passwd file is a text file that describes user login
accounts for the system.It should have read permission allowed for
all users(many utilities,like ls(1)use it to map user IDs to user‐
names),but write access only for the superuser.
In the good old days there was no great problem with this general
read permission.Everybody could read the encrypted passwords,but
the hardware was too slow to crack a well-chosen password,and more‐
over the basic assumption used to be that of a friendly user-commu‐
nity.These days many people run some version of the shadow password
suite,where/etc/passwd has an'x'character in the password
....
步骤二：使用zip命令制作压缩包
1）将目录/usr/share/doc/qemu-kvm/备份为/root/qemu-kvm.zip
[root@svr7~]#zip -r /root/qemu-kvm.zip /usr/share/doc/qemu-kvm/
adding:usr/share/doc/qemu-kvm/(stored 0%)
adding:usr/share/doc/qemu-kvm/COPYING(deflated 62%)
adding:usr/share/doc/qemu-kvm/COPYING.LIB(deflated 65%)
adding:usr/share/doc/qemu-kvm/Changelog(deflated 61%)
adding:usr/share/doc/qemu-kvm/LICENSE(deflated 45%)
adding:usr/share/doc/qemu-kvm/README(deflated 4%)
2）恢复测试
l 删除目标文件夹并确认结果：
[root@svr7~]#rm -rf /usr/share/doc/qemu-kvm/
[root@svr7~]#ls /usr/share/doc/qemu-kvm/
ls:cannot access/usr/share/doc/qemu-kvm/:No such file or directory
l 恢复目标文件夹并确认结果：
[root@svr7~]#unzip /root/qemu-kvm.zip-d/
Archive:/root/qemu-kvm.zip
creating:/usr/share/doc/qemu-kvm/
inflating:/usr/share/doc/qemu-kvm/COPYING
inflating:/usr/share/doc/qemu-kvm/COPYING.LIB
inflating:/usr/share/doc/qemu-kvm/Changelog
....
[root@svr7~]#ls /usr/share/doc/qemu-kvm/
COPYING README qemu-tech.html
COPYING.LIB README.rhel6-gpxe-source qmp-commands.txt
Changelog README.systemtap qmp-events.txt
LICENSE qemu-doc.html qmp-spec.txt