N25-第五周作业

第五周

1、显示/boot/grub/grub.conf中以至少一个空白字符开头的行；

[root@zf ~]# grep -E "^[[:space:]]+[[:alnum:]]+" /boot/grub/grub.conf
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=UUID=10c8f38a-aa7e-44ba-81e2-bddbb6689b7c rd_NO_LUKS
KEYBOARDTYPE=pc KEYTABLE=us rd_NO_MD.UTF-8 rd_NO_LVM rd_NO_DM rhgb quiet
initrd /initramfs-2.6.32-431.el6.x86_64.img

2、显示/etc/rc.d/rc.sysinit文件中以#开头，后面跟至少一个空白字符，而后又有至少一个非空白字符的行；

[root@zf ~]# grep -E "^#[[:space:]]+[^[:space:]]+" /etc/rc.d/rc.sysinit
# /etc/rc.d/rc.sysinit - run once at boot time
# Taken in part from Miquel van Smoorenburg's bcheckrc.
# Check SElinux status
# Print a text banner.
# Only read this once.
# Initialize hardware
# Set default affinity
# Load other user-defined modules
# Load modules (for backward compatibility with VARs)
# Configure kernel parameters
# Set the hostname.
# Sync waiting for storage.
# Device mapper & related initialization
# Start any MD RAID arrays that haven't been started yet
# Remount the root filesystem read-write.
# Clean up SELinux labels
# If relabeling, relabel mount points.
# Mount all other filesystems (except for NFS and /proc, which is already
# mounted). Contrary to standard usage,
# filesystems are NOT unmounted in single user mode.
# The 'no' applies to all listed filesystem types. See mount(8).
# Update quotas if necessary
# Check to see if a full relabel is needed
# Initialize pseudo-random number generator
# Configure machine if necessary.
# Clean out /.
# Do we need (w|u)tmpx files? We don't set them up, but the sysadmin might...
# Clean up /var.
# Clean up utmp/wtmp
# Clean up various /tmp bits
# Make ICE directory
# Start up swapping.
# Set up binfmt_misc
# Boot time profiles. Yes, this should be somewhere else.
# Now that we have all of our basic modules loaded and the kernel going,
# let's dump the syslog ring somewhere so we can find it later
# create the crash indicator flag to warn on crashes, offer fsck with timeout
# Let rhgb know that we're leaving rc.sysinit

3、打出netstat -tan命令执行结果中以‘LISTEN’，后或跟空白字符结尾的行；

[root@zf ~]# netstat -tan | grep -E "LISTEN[[:space:]]+$"
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:44177 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:10050 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN
tcp 0 0 :::111 :::* LISTEN
tcp 0 0 :::22 :::* LISTEN
tcp 0 0 ::1:631 :::* LISTEN
tcp 0 0 ::1:25 :::* LISTEN
tcp 0 0 :::55769 :::* LISTEN
tcp 0 0 :::3306 :::* LISTEN

4、添加用户bash, testbash, basher, nologin (此一个用户的shell为/sbin/nologin)，而后找出当前系统上其用户名和默认shell相同的用户的信息；

[root@zf ~]# useradd bash
[root@zf ~]# useradd testbash
[root@zf ~]# useradd basher
[root@zf ~]# useradd -s /sbin/nologin nologin
[root@zf ~]# shell=$(grep "basher" /etc/passwd | cut -d: -f7)
[root@zf ~]# grep "$shell" /etc/passwd | cut -d: -f1
root
aa
mageia
openstack
hadoop
bash
testbash
basher

5、显示当前系统上root、fedora或user1用户的默认shell；

[root@zf ~]# grep -E "^(root|fedora)\>" /etc/passwd | cut -d: -f1,7
root:/bin/bash
fedora:/bin/bash

6、找出/etc/rc.d/init.d/functions文件中某单词后面跟一组小括号的行，形如：hello()；

[root@zf ~]# grep -E "[[:alpha:]]+\>\(\)" /etc/rc.d/init.d/functions
fstab_decode_str() {
checkpid() {
__readlink() {
__fgrep() {
__umount_loop() {
__umount_loopback_loop() {
__pids_var_run() {
__pids_pidof() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
echo_success() {
echo_failure() {
echo_passed() {
echo_warning() {
update_boot_stage() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {
get_numeric_dev() {
is_ignored_file() {
is_true() {
is_false() {
apply_sysctl() {
key_is_random() {
find_crypto_mount_point() {
init_crypto() {

7、使用echo命令输出一个绝对路径，使用grep取出其基名； 扩展：取出其路径名

[root@zf ~]# echo "/usr/local/nginx/sbin" | grep -E -o "\<[[:alnum:]]+/?$"
sbin
[root@zf ~]# echo "/usr/local/nginx/sbin" | grep -E "^/[[:alnum:]/]+/?"
/usr/local/nginx/sbin

8、找出ifconfig命令结果中的1-255之间数字；

[root@zf ~]# ifconfig eth0 | grep -E -o "\<[1-9]\>|\<[1-9][0-9]\>|\<1[0-9][0-9]\>|\<2[0-4][0-9]\>|\<25[0-5]\>"
29
33
83
56
10
10
10
20
10
10
10
255
255
255
255
64
1
4
5
3
9

9、挑战题：写一个模式，能匹配合理的IP地址；

[root@zf tmp]# ifconfig | grep -E -o "\<(([01]?[0-9][0-9]?|24[0-9]|25[0-4])\.){3}([01]?[0-9][0-9]?|24[0-9]|25[0-4])\>"
10.10.10.30
10.4.2.3
127.0.0.1

10、挑战题：写一个模式，能匹配出所有的邮件地址；

[root@zf tmp]# cat mail_test
12457@qq.com
w2R3@163.com
Zhang.45e@mageedu.com
zd_jdf@pa-jd.com
eijm8@weij.com.cn
fjhiu@fngy.net
[root@zf tmp]# grep -E "[^[:space:]]*@*\.[^[:space:]]*$" mail_test
12457@qq.com
w2R3@163.com
Zhang.45e@mageedu.com
zd_jdf@pa-jd.com
eijm8@weij.com.cn
fjhiu@fngy.net

11、查找/var目录下属主为root，且属组为mail的所有文件或目录；

[root@zf ~]# find /var -user root -group mail
/var/spool/mail
/var/spool/mail/root

12、查找当前系统上没有属主或属组的文件； 进一步：查找当前系统上没有属主或属组，且最近3天内曾被访问过的文件或目录；

[root@zf ~]# find / \( -nouser -o -nogroup \)
/var/spool/mail/mandriva
/home/mandriva
/home/mandriva/.gnome2
/home/mandriva/.bash_profile
/home/mandriva/.bash_logout
/home/mandriva/.bashrc
/home/mandriva/.mozilla
/home/mandriva/.mozilla/extensions
/home/mandriva/.mozilla/plugins
[root@zf ~]# find / \( -nouser -o -nogroup \) -a -atime -3
/var/spool/mail/mandriva
/home/mandriva
/home/mandriva/.gnome2
/home/mandriva/.mozilla
/home/mandriva/.mozilla/extensions
/home/mandriva/.mozilla/plugins

13、查找/etc目录下所有用户都有写权限的文件；

[root@zf ~]# find /etc/ -perm -222
/etc/rc1.d
/etc/init.d
/etc/rc0.d
/etc/httpd/modules
/etc/httpd/run
/etc/httpd/logs
...

14、查找/etc目录下大于1M，且类型为普通文件的所有文件；

[root@zf ~]# find /etc/ -size +2M -a -type f
/etc/selinux/targeted/policy/policy.24
/etc/selinux/targeted/modules/active/policy.kern

15、查找/etc/init.d/目录下，所有用户都有执行权限，且其它用户有写权限的文件；

[root@zf ~]# find /etc/init.d/ -perm -113

16、查找/usr目录下不属于root、bin或hadoop的文件；

[root@zf ~]# find /usr/ -not \( -user root -o -user bin -o -user hadoop \)
/usr/local/nginx/scgi_temp
/usr/local/nginx/proxy_temp
/usr/local/nginx/fastcgi_temp
/usr/local/nginx/fastcgi_temp/1
/usr/local/nginx/fastcgi_temp/1/00
/usr/local/nginx/client_body_temp
/usr/local/nginx/uwsgi_temp
/usr/libexec/abrt-action-install-debuginfo-to-abrt-cache

17、查找/etc/目录下至少有一类用户没有写权限的文件；

[root@zf ~]# find /etc/ -not -perm -222
/etc/
/etc/rwtab
/etc/cron.deny
/etc/dnsmasq.d
/etc/.pwd.lock
...

18、查找/etc目录下最近一周内其内容被修改过，且不属于root或hadoop的文件；

[root@zf ~]# find /etc/ -mtime -7 -a -not \( -user root -o -user hadoop \)
/etc/yum.conf.bak