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
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[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
fi
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2、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
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[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 ~]
#
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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
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[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 ~]
#
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3、在/etc/issue每一行行首增加#号
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[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 ~]
#
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4、在/etc/fstab文件中不以#开头的行的行首增加#号
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[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 ~]
#
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5、处理/etc/fstab路径,使用sed命令取出其目录名和基名
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[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#(.*/)([^/]+/?)$#\2#g'
issue
[root@centos7 ~]
# echo "/etc/issue/" |grep '.*/\<'
/etc/issue/
[root@centos7 ~]
# echo "/etc/issue/" |grep -o '.*/\<'
/etc/
[root@centos7 ~]
# echo "/etc/issue/" |grep -o '[^/]\+/\?$'
issue/
[root@centos7 ~]
#
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6、利用sed 取出ifconfig命令中本机的IPv4地址
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[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 ~]
#
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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
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[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]
#
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本文转自chengong1013 51CTO博客，原文链接：http://blog.51cto.com/purify/1836292，如需转载请自行联系原作者
