1、显示/boot/grub/grub.conf中以至少一个空白字符开头的行；
[root@centos ~]# grep "^[[:space:]]\+" /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-504.el6.x86_64 ro root=/dev/mapper/vg_centos-lv_root rd_NO_LUKS.UTF-8 rd_LVM_LV=vg_centos/lv_swap rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_centos/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet initrd /initramfs-2.6.32-504.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@centos ~]# grep "^#[[: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@centos ~]# netstat -tan | grep "LISTEN[[:space:]]*$" 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 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:56665 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN tcp 0 0 :::22 :::* LISTEN tcp 0 0 ::1:631 :::* LISTEN tcp 0 0 :::51608 :::* LISTEN tcp 0 0 ::1:25 :::* LISTEN tcp 0 0 :::111 :::* 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@centos ~]# grep "^\([[:alnum:]]\+\b\).*\1$" /etc/passwd sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt
5、显示当前系统上root、fedora或user1用户的默认shell；
[root@centos ~]# for i in root fedora user1; do grep "^$i" /etc/passwd | cut -d: -f1,7; done root:/bin/bash fedora:/bin/bash user1:/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@centos ~]# grep "\b[[:alpha:]]\+\b()" /etc/rc.d/init.d/functions
checkpid() {
daemon() {
killproc() {
pidfileofproc() {
pidofproc() {
status() {
success() {
failure() {
passed() {
warning() {
action() {
strstr() {
confirm() {
7、使用echo命令输出一个绝对路径，使用grep取出其基名；
[root@centos ~]# echo "/etc/sysconfig/network-scripts/ifcfg-eth0" | grep -E -o "[^/]+/?$" | cut -d"/" -f1 ifcfg-eth0
扩展：取出其路径名
[root@centos ~]# echo "/etc/rc.d/rc.sysinit" | egrep -o "^(/.*/)" /etc/rc.d/
8、找出ifconfig命令结果中的1-255之间数字；
[root@centos ~]# ifconfig | egrep -o "\b`for i in {1..256};do echo $i; done;`"
29
7
51
192
168
40
128
192
168
9、挑战题：写一个模式，能匹配合理的IP地址；
[root@centos ~]# ifconfig | egrep -o "[1-2][0-9]?[0-9]?.[0-2]?[0-9]?[0-9].[0-2]?[0-9]?[0-9].[0-2]?[0-9]?[0-9]" 192.168.40.128 192.168.40.255 255.255.255.0 127.0.0.1 255.0.0.0
10、挑战题：写一个模式，能匹配出所有的邮件地址；
[root@centos ~]# cat mailaddress #yuan@baidu.com yuan_xin@baidu.com.cn smith@top.com__ 3982294699@qq.com xinixn@sina.com [root@centos ~]# cat mailaddress | egrep "^[[:alnum:]].*@[[:alnum:]]+[.].*[[:alnum:]]$" yuan_xin@baidu.com.cn 3982294699@qq.com xinixn@sina.com
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@centos ~]# find /var/ -user root -a -group mail /var/spool/mail
12、查找当前系统上没有属主或属组的文件；
[root@centos ~]# find / -nouser -o -nogroup -type f find: `/proc/3658/task/3658/fd/5': No such file or directory find: `/proc/3658/task/3658/fd/5': No such file or directory find: `/proc/3658/task/3658/fdinfo/5': No such file or directory find: `/proc/3658/task/3658/fdinfo/5': No such file or directory find: `/proc/3658/fd/5': No such file or directory find: `/proc/3658/fd/5': No such file or directory find: `/proc/3658/fdinfo/5': No such file or directory find: `/proc/3658/fdinfo/5': No such file or directory
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@centos ~]# find / -nouser -o -nogroup -a -atime -3 find: `/proc/2535/task/2535/fd/5': No such file or directory find: `/proc/2535/task/2535/fd/5': No such file or directory find: `/proc/2535/task/2535/fdinfo/5': No such file or directory find: `/proc/2535/task/2535/fdinfo/5': No such file or directory find: `/proc/2535/fd/5': No such file or directory find: `/proc/2535/fd/5': No such file or directory find: `/proc/2535/fdinfo/5': No such file or directory find: `/proc/2535/fdinfo/5': No such file or directory
13、查找/etc目录下所有用户都有写权限的文件；
[root@centos ~]# find /etc -perm -222 -exec ls -l {} \;
lrwxrwxrwx. 1 root root 10 Jun 2 18:13 /etc/rc5.d -> rc.d/rc5.d
lrwxrwxrwx. 1 root root 14 Jun 2 18:13 /etc/system-release -> centos-release
lrwxrwxrwx. 1 root root 19 Jun 2 18:25 /etc/pam.d/fingerprint-auth -> fingerprint-auth-ac
lrwxrwxrwx. 1 root root 25 Jun 2 18:14 /etc/pam.d/smtp -> /etc/alternatives/mta-pam
lrwxrwxrwx. 1 root root 14 Jun 2 18:25 /etc/pam.d/system-auth -> system-auth-ac
lrwxrwxrwx. 1 root root 16 Jun 2 18:25 /etc/pam.d/password-auth -> password-auth-ac
lrwxrwxrwx. 1 root root 17 Jun 2 18:25 /etc/pam.d/smartcard-auth -> smartcard-auth-ac
lrwxrwxrwx. 1 root root 10 Jun 2 18:13 /etc/rc3.d -> rc.d/rc3.d
lrwxrwxrwx. 1 root root 10 Jun 2 18:13 /etc/rc6.d -> rc.d/rc6.d
14、查找/etc目录下大于1M，且类型为普通文件的所有文件；
[root@centos ~]# find /etc/ -type f -size +1M
/etc/selinux/targeted/modules/active/policy.kern
/etc/selinux/targeted/policy/policy.24
/etc/gconf/gconf.xml.defaults/%gconf-tree.xml
[root@centos ~]# find /etc/ -type f -size +1M -exec ls -lh {} \;
-rw-r--r--. 1 root root 7.8M Jun 2 18:17 /etc/selinux/targeted/modules/active/policy.kern
-rw-r--r--. 1 root root 7.8M Jun 2 18:17 /etc/selinux/targeted/policy/policy.24
-rw-r--r--. 1 root root 2.2M Jun 2 18:21 /etc/gconf/gconf.xml.defaults/%gconf-tree.xml
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@centos ~]# find /etc/init.d/ -perm -113 -exec ls -lh {} \;
16、查找/usr目录下不属于root、bin或hadoop的文件；
[root@centos ~]# find /usr/ -not \( -user root -o -user bin -o -user hadoop \)
17、查找/etc/目录下至少有一类用户没有写权限的文件；
[root@centos ~]# find /etc/ -not -perm -222 -ls | less 260098 12 drwxr-xr-x 118 root root 12288 Jul 23 10:27 /etc/ 260242 4 -rw-r--r-- 1 root root 801 Jul 19 2011 /etc/gssapi_mech.conf 260103 4 drwxr-xr-x 2 root root 4096 Jun 2 18:19 /etc/modprobe.d 260106 4 -rw-r--r-- 1 root root 52 Jun 2 18:06 /etc/modprobe.d/anaconda.conf 260348 4 -rw-r--r-- 1 root root 884 Oct 16 2014 /etc/modprobe.d/blacklist.conf 260345 4 -rw-r--r-- 1 root root 382 Oct 15 2014 /etc/modprobe.d/dist-alsa.conf 260347 8 -rw-r--r-- 1 root root 5596 Oct 15 2014 /etc/modprobe.d/dist.conf 273795 4 -rw-r--r-- 1 root root 30 Oct 10 2009 /etc/modprobe.d/openfwwf.conf 260346 4 -rw-r--r-- 1 root root 473 Oct 15 2014 /etc/modprobe.d/dist-oss.conf 264283 4 -rw-r--r-- 1 root root 524 Oct 16 2014 /etc/auto.misc 260162 4 -rw-r--r-- 1 root root 272 Nov 18 2009 /etc/mailcap
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@centos ~]# find /etc/ -mtime -7 -a -not \( -user root -o -user hadoop\)
原创文章，作者：Snoo，如若转载，请注明出处：http://www.178linux.com/25230
评论列表（1条）
写的很好，排版也很棒，第8题不是我们要的结果，在想象，用grep做。加油