感觉进入了年底,明显的时间不够,不管怎么说,还是要努力跟上学习的进度,不能给自己松懈找借口!
1、显示/boot/grub/grub.conf中以至少一个空白字符开头的行;
[root@localhost ~]# grep "^[[:space:]]\+" /boot/grub/grub.conf root (hd0,0) kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup/lv_root KEYBOARDTYPE=pc KEYTABLE=us 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@localhost ~]# 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 ...
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@localhost ~]# netstat -tan | grep "LISTEN[[:space:]]*$" tcp 0 0 0.0.0.0:111 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 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 0 0.0.0.0:35227 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 :::46560 :::* 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@localhost ~]# useradd bash [root@localhost ~]# useradd testbash [root@localhost ~]# useradd basher [root@localhost ~]# useradd -s /sbin/nologin nologin [root@localhost ~]# grep "^\([^:]\+\>\).*\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 bash:x:500:500::/home/bash:/bin/bash nologin:x:503:503::/home/nologin:/sbin/nologin
5、显示当前系统上root、fedora或user1用户的默认shell;
因为当前系统没有fedora和user1用户,所以先创建。
[root@localhost ~]# useradd fedora [root@localhost ~]# useradd user1 [root@localhost ~]# grep "^\(root\|fedora\|user1\)" /etc/passwd root:x:0:0:root:/root:/bin/bash fedora:x:504:504::/home/fedora:/bin/bash user1:x:505:505::/home/user1:/bin/bash [root@localhost ~]# grep "^\(root\|fedora\|user1\)" /etc/passwd | cut -d: -f7 /bin/bash /bin/bash /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();
根据对题目的理解,应该是要小括号内为空的内容,也就是一对括号,而不是括号内可以有内容的行。
[root@localhost ~]# grep "\<[[:alnum:]]\+\>()" /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;
扩展:取出其路径名
[root@localhost ~]# echo /etc/rc.d/init.d/functions | grep "\<[^/]\+$" -o functions [root@localhost ~]# echo /etc/rc.d/init.d/functions | grep "/.*/" -o /etc/rc.d/init.d/
8、找出ifconfig命令结果中的1-255之间数字;
[root@localhost ~]# ifconfig | grep "\<[1-9]\>\|\<[1-9][0-9]\>\|\<1[0-9][0-9]\>\|2[0-4][0-9]\|25[0-5]" -o 29 172 16 209 172 16 3 255 255 ...
9、挑战题:写一个模式,能匹配合理的IP地址;
[root@localhost ~]# ifconfig | grep "\(\([01]\?[0-9]\?[0-9]\?\|2\?[0-4]\?[0-9]\?\|25\?[0-5]\?\)\.\)\{3\}\([01]\?[0-9]\?[0-9]\?\|2\?[0-4]\?[0-9]\?\|25\?[0-5]\?\)" -o 172.16.0.209 172.16.3.255 255.255.252.0 127.0.0.1 255.0.0.0
10、挑战题:写一个模式,能匹配出所有的邮件地址;
不是太懂email的格式要求,但是一般字符只能用-和_所以就只允许这两个了。
[root@localhost ~]# cat /tmp/mail.txt abc@abc.com abc12@abc12.com 12abc@12abc.cn a_bc12@12.org bcd2@bc_2.net ab$@cd.cn cd#@cs.cc ty%@.com mc^d@cd.com sb&@dds.csg ss*@dds(.com [root@localhost ~]# grep "^[0-9a-zA-Z\-\_]\+@\{1\}[0-9a-zA-Z\-\_]\+.[0-9a-zA-Z\-\_]\+$" /tmp/mail.txt abc@abc.com abc12@abc12.com 12abc@12abc.cn a_bc12@12.org bcd2@bc_2.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@localhost ~]# find /var -user root -group mail -ls 2229008 4 drwxrwxr-x 2 root mail 4096 Jan 3 02:06 /var/spool/mail
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;
#由于系统上没有无属主或属组的文件,所以先做一些类似的文件出来。
[root@localhost ~]# chown user1:fedora /tmp/mail.txt [root@localhost ~]# cp /etc/issue /tmp [root@localhost ~]# cp /etc/rc.d/init.d/functions /tmp [root@localhost ~]# chown testbash:mail /tmp/issue [root@localhost ~]# chown basher:fedora /tmp/functions [root@localhost ~]# ll /tmp total 28 -rw-r--r--. 1 basher fedora 18586 Jan 3 04:27 functions -rw-r--r--. 1 testbash mail 47 Jan 3 04:27 issue -rw-r--r--. 1 user1 fedora 138 Jan 3 03:49 mail.txt [root@localhost ~]# userdel basher [root@localhost ~]# userdel testbash [root@localhost ~]# userdel fedora [root@localhost ~]# userdel user1 [root@localhost ~]# ll /tmp total 28 -rw-r--r--. 1 502 504 18586 Jan 3 04:27 functions -rw-r--r--. 1 501 mail 47 Jan 3 04:27 issue -rw-r--r--. 1 505 504 138 Jan 3 03:49 mail.txt [root@localhost ~]# find / \( -nouser -o -nogroup \) -ls find: `/proc/2941/task/2941/fd/5': No such file or directory find: `/proc/2941/task/2941/fd/5': No such file or directory find: `/proc/2941/task/2941/fdinfo/5': No such file or directory find: `/proc/2941/task/2941/fdinfo/5': No such file or directory find: `/proc/2941/fd/5': No such file or directory find: `/proc/2941/fd/5': No such file or directory find: `/proc/2941/fdinfo/5': No such file or directory find: `/proc/2941/fdinfo/5': No such file or directory 3932161 4 drwx------ 2 504 504 4096 Jan 3 02:06 /home/fedora 3932162 4 -rw-r--r-- 1 504 504 18 Jul 18 2013 /home/fedora/.bash_logout 3932164 4 -rw-r--r-- 1 504 504 124 Jul 18 2013 /home/fedora/.bashrc 3932163 4 -rw-r--r-- 1 504 504 176 Jul 18 2013 /home/fedora/.bash_profile 131073 4 drwx------ 2 505 505 4096 Jan 3 02:06 /home/user1 131074 4 -rw-r--r-- 1 505 505 18 Jul 18 2013 /home/user1/.bash_logout 131076 4 -rw-r--r-- 1 505 505 124 Jul 18 2013 /home/user1/.bashrc 131075 4 -rw-r--r-- 1 505 505 176 Jul 18 2013 /home/user1/.bash_profile 655361 4 drwx------ 2 502 502 4096 Jan 3 01:36 /home/basher 655362 4 -rw-r--r-- 1 502 502 18 Jul 18 2013 /home/basher/.bash_logout 655364 4 -rw-r--r-- 1 502 502 124 Jul 18 2013 /home/basher/.bashrc 655363 4 -rw-r--r-- 1 502 502 176 Jul 18 2013 /home/basher/.bash_profile 524289 4 drwx------ 2 501 501 4096 Jan 3 01:36 /home/testbash 524290 4 -rw-r--r-- 1 501 501 18 Jul 18 2013 /home/testbash/.bash_logout 524292 4 -rw-r--r-- 1 501 501 124 Jul 18 2013 /home/testbash/.bashrc 524291 4 -rw-r--r-- 1 501 501 176 Jul 18 2013 /home/testbash/.bash_profile 2230209 0 -rw-rw---- 1 505 mail 0 Jan 3 02:06 /var/spool/mail/user1 2230206 0 -rw-rw---- 1 502 mail 0 Jan 3 01:36 /var/spool/mail/basher 2230208 0 -rw-rw---- 1 504 mail 0 Jan 3 02:06 /var/spool/mail/fedora 2230193 0 -rw-rw---- 1 501 mail 0 Jan 3 01:36 /var/spool/mail/testbash 2752517 20 -rw-r--r-- 1 502 504 18586 Jan 3 04:27 /tmp/functions 2752514 4 -rw-r--r-- 1 501 mail 47 Jan 3 04:27 /tmp/issue 2752516 4 -rw-r--r-- 1 505 504 138 Jan 3 03:49 /tmp/mail.txt [root@localhost ~]# find / \( -nouser -o -nogroup \) -a -atime -3 -ls find: `/proc/2927/task/2927/fd/5': No such file or directory find: `/proc/2927/task/2927/fdinfo/5': No such file or directory find: `/proc/2927/fd/5': No such file or directory find: `/proc/2927/fdinfo/5': No such file or directory 3932161 4 drwx------ 2 504 504 4096 Jan 3 02:06 /home/fedora 3932162 4 -rw-r--r-- 1 504 504 18 Jul 18 2013 /home/fedora/.bash_logout 3932164 4 -rw-r--r-- 1 504 504 124 Jul 18 2013 /home/fedora/.bashrc 3932163 4 -rw-r--r-- 1 504 504 176 Jul 18 2013 /home/fedora/.bash_profile 131073 4 drwx------ 2 505 505 4096 Jan 3 02:06 /home/user1 131074 4 -rw-r--r-- 1 505 505 18 Jul 18 2013 /home/user1/.bash_logout 131076 4 -rw-r--r-- 1 505 505 124 Jul 18 2013 /home/user1/.bashrc 131075 4 -rw-r--r-- 1 505 505 176 Jul 18 2013 /home/user1/.bash_profile 655361 4 drwx------ 2 502 502 4096 Jan 3 01:36 /home/basher 655362 4 -rw-r--r-- 1 502 502 18 Jul 18 2013 /home/basher/.bash_logout 655364 4 -rw-r--r-- 1 502 502 124 Jul 18 2013 /home/basher/.bashrc 655363 4 -rw-r--r-- 1 502 502 176 Jul 18 2013 /home/basher/.bash_profile 524289 4 drwx------ 2 501 501 4096 Jan 3 01:36 /home/testbash 524290 4 -rw-r--r-- 1 501 501 18 Jul 18 2013 /home/testbash/.bash_logout 524292 4 -rw-r--r-- 1 501 501 124 Jul 18 2013 /home/testbash/.bashrc 524291 4 -rw-r--r-- 1 501 501 176 Jul 18 2013 /home/testbash/.bash_profile 2230209 0 -rw-rw---- 1 505 mail 0 Jan 3 02:06 /var/spool/mail/user1 2230206 0 -rw-rw---- 1 502 mail 0 Jan 3 01:36 /var/spool/mail/basher 2230208 0 -rw-rw---- 1 504 mail 0 Jan 3 02:06 /var/spool/mail/fedora 2230193 0 -rw-rw---- 1 501 mail 0 Jan 3 01:36 /var/spool/mail/testbash 2752517 20 -rw-r--r-- 1 502 504 18586 Jan 3 04:27 /tmp/functions 2752514 4 -rw-r--r-- 1 501 mail 47 Jan 3 04:27 /tmp/issue 2752516 4 -rw-r--r-- 1 505 504 138 Jan 3 03:49 /tmp/mail.txt
13、查找/etc目录下所有用户都有写权限的文件;
[root@localhost ~]# find /etc -perm -222 -type f -ls ...
14、查找/etc目录下大于1M,且类型为普通文件的所有文件;
[root@localhost ~]# find /etc -type f -size +1M -ls 1181096 7124 -rw-r--r-- 1 root root 7292689 Dec 21 04:02 /etc/selinux/targeted/policy/policy.24 1181093 7124 -rw-r--r-- 1 root root 7292689 Dec 21 04:02 /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;
没有其他用户有写权限的文件,所以将查询改为读和执行。
[root@localhost ~]# find /etc/rc.d/init.d -perm -114 -type f -ls 1179729 4 drwxr-xr-x 2 root root 4096 Jan 3 02:12 /etc/rc.d/init.d 1180321 4 -rwxr-xr-x 1 root root 652 Oct 10 2013 /etc/rc.d/init.d/killall 1181236 4 -rwxr-xr-x 1 root root 1725 Aug 19 2010 /etc/rc.d/init.d/acpid 1181220 4 -rwxr-xr-x 1 root root 2034 Jun 13 2013 /etc/rc.d/init.d/quota_nld 1180644 4 -rwxr-xr-x 1 root root 2094 Feb 22 2013 /etc/rc.d/init.d/certmonger 1181162 4 -r-xr-xr-x 1 root root 2134 Nov 24 2013 /etc/rc.d/init.d/lvm2-lvmetad 1179849 4 -rwxr-xr-x 1 root root 2023 Apr 3 2012 /etc/rc.d/init.d/portreserve 1180609 4 -rwxr-xr-x 1 root root 2011 Aug 15 2013 /etc/rc.d/init.d/rsyslog 1181122 4 -rwxr-xr-x 1 root root 1144 Nov 23 2013 /etc/rc.d/init.d/sysstat ...
16、查找/usr目录下不属于root、bin或hadoop的文件;
[root@localhost ~]# find /usr -not \( -user root -o -user bin \) -ls 1314588 12 -rwsr-xr-x 1 abrt abrt 9904 Nov 23 2013 /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@localhost ~]# find /etc -perm /222 -type f -ls 1179706 4 -rw-r--r-- 1 root root 236 Nov 12 2010 /etc/sgml/docbook/xmlcatalog 1180292 4 -rw-r--r-- 1 root root 48 Dec 28 01:18 /etc/adjtime 1179780 0 -rw-r--r-- 1 root root 0 Nov 29 2012 /etc/odbc.ini 1179983 4 -rw-r--r-- 1 root root 251 Nov 23 2013 /etc/my.cnf 1180066 4 -rw-r--r-- 1 root root 2293 Apr 5 2012 /etc/libuser.conf 1179964 16 -rw-r--r-- 1 root root 13537 Dec 16 2004 /etc/java/font.properties 1179965 4 -rw-r--r-- 1 root root 684 Nov 12 2010 /etc/java/java.conf 1179966 4 -rw-r--r-- 1 root root 50 Nov 12 2010 /etc/java/jpackage-release ...
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@localhost ~]# find /etc \( -not -user root -a -not -user bin \) -a -mtime -7
原创文章,作者:N25-Johnny,如若转载,请注明出处:http://www.178linux.com/65650
评论列表(1条)
写的很好,排版也很漂亮,提问一个问题,255.255.255.255是一个合理的ip地址吗?