6、显示/proc/meminfo文件中以大写或小写S开头的行；用两种方式；
1、
[root@suywien ~]# grep ^[S,s] /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 9100 kB Slab: 89476 kB SReclaimable: 53176 kB SUnreclaim: 36300 kB
2、
[root@suywien ~]# grep -i "^s" /proc/meminfo SwapCached: 0 kB SwapTotal: 2097148 kB SwapFree: 2097148 kB Shmem: 9100 kB
7、显示/etc/passwd文件中其默认shell为非/sbin/nologin的用户；
[root@suywien ~]# grep /sbin/nologin$ /etc/passwd bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin mail:x:8:12:mail:/var/spool/mail:/sbin/nologin ......
8、显示/etc/passwd文件中其默认shell为/bin/bash的用户；
[root@suywien ~]# grep /bin/bash /etc/passwd root:x:0:0:root:/root:/bin/bash roo:x:1000:1000:root:/home/roo:/bin/bash gentoo:x:4001:4001::/home/gentoo:/bin/bash mageia:x:1100:1100::/home/linux:/bin/bash tuser:x:4003:4003::/home/tuser1/:/bin/bash hadoop:x:1029:1029::/home/hodoop/:/bin/bash
9、找出/etc/passwd文件中的一位数或两位数；
[root@suywien ~]# grep "<[0-9]{2,3}>" /etc/passwd
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
......
10、显示/boot/grub/grub.conf中以至少一个空白字符开头的行；
[root@suywien ~]# grep "^[[:space:]]+" /boot/grub2/grub.cfg
load_env
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
......
11、显示/etc/rc.d/rc.sysinit文件中以#开头，后面跟至少一个空白字符，而后又有至少一个非空白字符的行；
[root@suywien ~]# grep "^#[[:space:]]+[^[:space:]]+" /etc/rc.d/rc.local # THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES # It is highly advisable to create own systemd services or udev rules # to run scripts during boot instead of using this file. # In contrast to previous versions due to parallel execution during boot # this script will NOT be run after all other services. # Please note that you must run 'chmod +x /etc/rc.d/rc.local' to ensure # that this script will be executed during boot.
12、打出netstat -tan命令执行结果中以‘LISTEN'，后或跟空白字符结尾的行；
[root@suywien ~]# netstat -tan | grep "LISTEN[[:space:]]*$" tcp 0 0 192.168.122.1:53 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 tcp6 0 0 :::22 :::* LISTEN tcp6 0 0 ::1:631 :::* LISTEN tcp6 0 0 ::1:25 :::* LISTEN
