8、找出ifconfig命令结果中的1-255之间数字;
[root@localhost ~]# ifconfig | grep -E -o "\b(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]{1,2})\b" 192 168 1 104 255 255 255 192 168 1 255 64 29 41 25 116 4 111 73 127 1 255 1 128 4 4 192 168 122 1 255 255 255 192 168 122 255 [root@localhost ~]#9、挑战题:写一个模式,能匹配合理的IP地址;
[root@localhost ~]# ifconfig | grep -P -o "\b((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)\b" 192.168.1.104 255.255.255.0 192.168.1.255 127.0.0.1 255.0.0.0 192.168.122.1 255.255.255.0 192.168.122.255 或者 [root@localhost ~]# ifconfig | grep -E -o "((2[0-4][0-9]|25[0-5]|[01]?[0-9][0-9]?)\.){3}(2[0-4][0-9]|25[0-5]|[01]?[0-9][0-9]?)" 192.168.1.104 255.255.255.0 192.168.1.255 127.0.0.1 255.0.0.0 192.168.122.1 255.255.255.0 192.168.122.255以上是匹配所有的ip地址。
如果要匹配跟随inet后面的地址则为:
[root@localhost ~]# ifconfig | grep "inet\b" | cut -d" " -f10 192.168.1.104 127.0.0.1 192.168.122.1 [root@localhost ~]#10、挑战题:写一个模式,能匹配出所有的邮件地址;
[root@localhost ~]# grep -E -o "\b[^[:space:]]+\@[^[:space:]]+\b" /tmp/test/mailstest.text 163frj@msina.com 4355@qq.com greatwall_china@gov.com goodluck_232@facebook.com 455iirr@rl.ro ab55&00_@gmail.com11、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 134221194 4 drwxrwxr-x 2 root mail 4096 Dec 22 06:48 /var/spool/mail 137126650 132 -rw------- 1 root mail 131956 Nov 30 19:31 /var/spool/mail/root12、查找当前系统上没有属主或属组的文件;
[root@localhost ~]# find / -nouser -o -nogroup -ls find: ‘/proc/15106’: No such file or directory find: ‘/proc/15114/task/15114/fd/6’: No such file or directory find: ‘/proc/15114/task/15114/fdinfo/6’: No such file or directory find: ‘/proc/15114/fd/6’: No such file or directory find: ‘/proc/15114/fdinfo/6’: 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@localhost ~]# find / \( -nouser -o -nogroup \) -atime -3 -ls find: ‘/proc/16974/task/16974/fd/6’: No such file or directory find: ‘/proc/16974/task/16974/fdinfo/6’: No such file or directory find: ‘/proc/16974/fd/6’: No such file or directory find: ‘/proc/16974/fdinfo/6’: No such file or directory 403645670 0 drwx------ 3 1002 1002 74 Nov 12 16:21 /home/slackware 3484079 0 drwxr-xr-x 4 1002 1002 37 Nov 8 20:14 /home/slackware/.mozilla 137119261 0 drwxr-xr-x 2 1002 1002 6 Jun 9 2014 /home/slackware/.mozilla/extensions 272578502 0 drwxr-xr-x 2 1002 1002 6 Jun 9 2014 /home/slackware/.mozilla/plugins 405829138 0 drwx------ 3 200 1005 74 Nov 16 19:03 /home/openstack 4526238 0 drwxr-xr-x 4 200 1005 37 Nov 8 20:14 /home/openstack/.mozilla 137132447 0 drwxr-xr-x 2 200 1005 6 Jun 9 2014 /home/openstack/.mozilla/extensions 272578520 0 drwxr-xr-x 2 200 1005 6 Jun 9 2014 /home/openstack/.mozilla/plugins 405829147 0 drwx------ 3 1005 1007 74 Nov 16 19:16 /home/mix 4334240 0 drwxr-xr-x 4 1005 1007 37 Nov 8 20:14 /home/mix/.mozilla 137132451 0 drwxr-xr-x 2 1005 1007 6 Jun 9 2014 /home/mix/.mozilla/extensions 272578522 0 drwxr-xr-x 2 1005 1007 6 Jun 9 2014 /home/mix/.mozilla/plugins 139922069 0 drwx------ 3 1005 distro 74 Dec 20 04:30 /home/mandriva 270994653 0 drwxr-xr-x 4 1005 distro 37 Nov 8 20:14 /home/mandriva/.mozilla 405832494 0 drwxr-xr-x 2 1005 distro 6 Jun 9 2014 /home/mandriva/.mozilla/extensions 3482209 0 drwxr-xr-x 2 1005 distro 6 Jun 9 2014 /home/mandriva/.mozilla/plugins