第五周
1、顯示/boot/grub/grub.conf中以至少一個空白字符開頭的行；
[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、顯示/etc/rc.d/rc.sysinit文件中以#開頭，后面跟至少一個空白字符，而后又有至少一個非空白字符的行；
[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命令執行結果中以‘LISTEN’，后或跟空白字符結尾的行；
[root@zf ~]# netstat -tan | grep -E "LISTEN[[:space:]]*$" tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:44177 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:10050 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN tcp 0 0 :::111 :::* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* LISTEN tcp 0 0 ::1:25 :::* LISTEN tcp 0 0 :::55769 :::* LISTEN tcp 0 0 :::3306 :::* LISTEN
4、添加用戶bash, testbash, basher, nologin (此一個用戶的shell為/sbin/nologin)，而后找出當前系統上其用戶名和默認shell相同的用戶的信息；
[root@zf ~]# useradd bash [root@zf ~]# useradd testbash [root@zf ~]# useradd basher [root@zf ~]# useradd -s /sbin/nologin nologin [root@zf ~]# shell=$(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、顯示當前系統上root、fedora或user1用戶的默認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文件中某單詞后面跟一組小括號的行，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命令輸出一個絕對路徑，使用grep取出其基名； 擴展：取出其路徑名
[root@zf ~]# echo "/usr/local/nginx/sbin/" | grep -E -o "[[:alnum:]]+/?$" | grep -o "[[:alnum:]]*" sbin [root@zf ~]# echo "/usr/local/nginx/sbin/" | grep -E -o "[/[:alnum:]]+\>" | grep -E -o "^/[/[:alnum:]]+/" /usr/local/nginx/
8、找出ifconfig命令結果中的1-255之間數字；
[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、挑戰題：寫一個模式，能匹配合理的IP地址；
[root@zf tmp]# ifconfig | grep -E -o "\<((1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.){3}(1?[1-9][0-9]?|2[0-4][0-9]|25[0-4])\>"
10.10.10.30
10.4.2.3
127.0.0.1
10、挑戰題：寫一個模式，能匹配出所有的郵件地址；
[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 -o "\<[^[:space:]]*\>@\<[^[: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目錄下屬主為root，且屬組為mail的所有文件或目錄；
[root@zf ~]# find /var -user root -group mail /var/spool/mail /var/spool/mail/root
12、查找當前系統上沒有屬主或屬組的文件； 進一步：查找當前系統上沒有屬主或屬組，且最近3天內曾被訪問過的文件或目錄；
[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目錄下所有用戶都有寫權限的文件；
[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目錄下大于1M，且類型為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/目錄下，所有用戶都有執行權限，且其它用戶有寫權限的文件；
[root@zf ~]# find /etc/init.d/ -perm -113
16、查找/usr目錄下不屬于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/目錄下至少有一類用戶沒有寫權限的文件；
[root@zf ~]# find /etc/ -not -perm -222 /etc/ /etc/rwtab /etc/cron.deny /etc/dnsmasq.d /etc/.pwd.lock ...
18、查找/etc目錄下最近一周內其內容被修改過，且不屬于root或hadoop的文件；
[root@zf ~]# find /etc/ -mtime -7 -a -not \( -user root -o -user hadoop \) /etc/yum.conf.bak
原創文章，作者：N25-深圳-尋覓，如若轉載，請注明出處：http://www.www58058.com/64833
寫的很好，排版也很棒，繼續保持，加油。