1、删除/etc/grub2.conf文件中所有以空白开头的行行首的空白字符
[root@centos7 ~]# sed -r ‘s#^[[:space:]]+##g‘ /etc/grub2.cfg
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub2-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#
### BEGIN /etc/grub.d/00_header ###
set pager=1
if [ -s $prefix/grubenv ]; then
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="${saved_entry}"
fi
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi
export menuentry_id_option
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi2、删除/etc/fstab文件中所有以#开头，后面至少跟一个空白字符的行的行首的#和空白字符
[root@centos7 ~]# sed -r ‘s/^#[[:space:]]+//g‘ /etc/fstab # /etc/fstab Created by anaconda on Tue Jul 19 14:39:24 2016 # Accessible filesystems, by reference, are maintained under ‘/dev/disk‘ See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # UUID=f83c52ce-5740-4f02-bb87-6e190360dc30 / xfs defaults 0 0 UUID=c98144e4-d1b4-45b1-bb22-3112420ea487 /boot xfs defaults 0 0 UUID=dbf5c483-133e-4888-bbb1-a9622d83a930 swap swap defaults 0 0 #END [root@centos7 ~]#
2.1、删除/etc/fstab文件中所有以#开头，后面至少跟一个空白字符的行的行首的#和空白字符且删除以#开头后面全是空白字符的行
[root@centos7 ~]# sed -r -e ‘s/^#[[:space:]]+//g‘ -e ‘/^#/d‘ /etc/fstab /etc/fstab Created by anaconda on Tue Jul 19 14:39:24 2016 Accessible filesystems, by reference, are maintained under ‘/dev/disk‘ See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info UUID=f83c52ce-5740-4f02-bb87-6e190360dc30 / xfs defaults 0 0 UUID=c98144e4-d1b4-45b1-bb22-3112420ea487 /boot xfs defaults 0 0 UUID=dbf5c483-133e-4888-bbb1-a9622d83a930 swap swap defaults 0 0 [root@centos7 ~]#
3、在/etc/issue每一行行首增加#号
[root@centos7 ~]# cat -n /etc/issue 1\S 2Kernel \r on an \m 3 [root@centos7 ~]# sed -r ‘s@(.*)@#&@g‘ /etc/issue #\S #Kernel \r on an \m # [root@centos7 ~]# sed -r ‘s@(.*)@#\1@g‘ /etc/issue #\S #Kernel \r on an \m # [root@centos7 ~]# sed -r ‘s@^@#@g‘ /etc/issue #\S #Kernel \r on an \m # [root@centos7 ~]#
4、在/etc/fstab文件中不以#开头的行的行首增加#号
[root@centos7 ~]# sed -r ‘s/^[^#]/#/g‘ /etc/fstab # # /etc/fstab # Created by anaconda on Tue Jul 19 14:39:24 2016 # # Accessible filesystems, by reference, are maintained under ‘/dev/disk‘ # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # #UID=f83c52ce-5740-4f02-bb87-6e190360dc30 / xfs defaults #UID=c98144e4-d1b4-45b1-bb22-3112420ea487 /boot xfs defaults #UID=dbf5c483-133e-4888-bbb1-a9622d83a930 swap swap defaults #END [root@centos7 ~]#
5、处理/etc/fstab路径,使用sed命令取出其目录名和基名
[root@centos7 Packages]# cd [root@centos7 ~]# echo "/etc/hosts"|sed -r ‘s#/.*/([^/]+)#\1#g‘ hosts [root@centos7 ~]# echo "/etc/hosts" |sed -r ‘s#(/.*/)[^/]+/?#\1#g‘ /etc/ [root@centos7 ~]# echo "/etc/issue"|sed -r ‘s#(.*/)([^/]+/?)$#\1#g‘ /etc/ [root@centos7 ~]# echo "/etc/issue"|sed -r ‘s#(.*/)([^/]+/?)$#\2#g‘ issue [root@centos7 ~]#
6、利用sed 取出ifconfig命令中本机的IPv4地址
[root@centos7 ~]# ifconfig |sed -n 2p inet 192.168.226.138 netmask 255.255.255.0 broadcast 192.168.226.255 [root@centos7 ~]# ifconfig |sed -n 2p|sed -r ‘s/.*net //g‘ 192.168.226.138 netmask 255.255.255.0 broadcast 192.168.226.255 [root@centos7 ~]# ifconfig |sed -n 2p|sed -r ‘s/.*net //g‘|sed -r ‘s/ net.*//g‘ 192.168.226.138 [root@centos7 ~]# ifconfig |sed -nr ‘2s#^.*net (.*) netm.*$#\1#gp‘ 192.168.226.138 [root@centos7 ~]#
7、统计centos安装光盘中Package目录下的所有rpm文件的 以.分隔倒数第二个字段的重复次数
[root@centos7 Packages]# ls *.rpm |sed -r ‘s/^.*\.(.*)\.rpm/\1/g‘|sort |uniq -c |sort 2000 i686 2938 noarch 4069 x86_64 [root@centos7 Packages]# ls *.rpm |rev |cut -d. -f2 |sort|uniq -c|uniq 4069 46_68x 2000 686i 2938 hcraon [root@centos7 Packages]#
本文出自 “叫醒你的不是闹钟而是梦想” 博客，请务必保留此出处http://purify.blog.51cto.com/10572011/1836292
原文：http://purify.blog.51cto.com/10572011/1836292