grep, sed(流编辑器/数据流编辑器), awk(报告文本生成器)
17.1 sed基本用法:
sed: Stream Editor
行编辑器 (全屏编辑器: vi)
sed: 模式空间
默认不编辑原文件,仅对模式空间中的数据做处理;而后,处理结束后,将模式空间打印至屏幕;
sed [options] 'AddressCommand' file ...
-n: 静默模式,不再默认显示模式空间中的内容
-i: 直接修改原文件
-e SCRIPT 可以同时执行多个脚本
添加脚本到被执行的命令当中
-f /PATH/TO/SED_SCRIPT
sed -f /path/to/scripts file
添加脚本的内容到被执行的命令当中
-r: 表示使用扩展正则表达式
17.2 Address制定方法:
1、StartLine,EndLine(起始行到结束行)
比如1,100:第一行开始到第100行结束
$:最后一行
$-1:倒数第二行
2、/RegExp/(使用正则表达式来指定模式)
/^root/
3、/pattern1/,/pattern2/
第一次被pattern1匹配到的行开始,至第一次被pattern2匹配到的行结束,这中间的所有行
4、LineNumber
指定的行(指定精确某一行)
5、StartLine, +N
从startLine开始,向后的N行,总共是N+1行
17.3 Command:
d: 删除符合条件的行;
p: 显示符合条件的行;
a \string: 在指定的行后面追加新行,内容为string
\n:可以用于换行
i \string: 在指定的行前面添加新行,内容为string
r FILE: 将指定的文件的内容添加至符合条件的行处
w FILE: 将地址指定的范围内的行另存至指定的文件中;
s/pattern/string/修饰符: 查找并替换,默认只替换每行中第一次被模式匹配到的字符串
加修饰符(想要让所有的都替换的话要加修饰符)
g: 全局替换
i: 忽略字符大小写
s///: s###, s@@@ 效果都一样
\(\), \1, \2,… 后向引用在这里也适用
l..e: like-->liker
love-->lover
like-->Like
love-->Love
&: 引用模式匹配到的整个字符串
sed练习:
1、删除/etc/grub.conf文件中行首的空白符;
sed -r 's@^[[:spapce:]]+@@g' /etc/grub.conf
[root@Daniel-R480 ~]# cat /etc/grub.conf
default=0
timeout=0
title CentOS Linux 7 (3.10.0-957.1.3.el7.x86_64)
root (hd0)
kernel /boot/vmlinuz-3.10.0-957.1.3.el7.x86_64 ro root=UUID=f41e390f-835b-4223-a9bb-9b45984ddf8d console=hvc0 LANG=en_US.UTF-8
initrd /boot/initramfs-3.10.0-957.1.3.el7.x86_64.img
[root@Daniel-R480 ~]# sed -r 's@^[[:space:]]+@@g' /etc/grub.conf
default=0
timeout=0
title CentOS Linux 7 (3.10.0-957.1.3.el7.x86_64)
root (hd0)
kernel /boot/vmlinuz-3.10.0-957.1.3.el7.x86_64 ro root=UUID=f41e390f-835b-4223-a9bb-9b45984ddf8d console=hvc0 LANG=en_US.UTF-8
initrd /boot/initramfs-3.10.0-957.1.3.el7.x86_64.img
[root@Daniel-R480 ~]#
2、替换/etc/inittab文件中"id:3:initdefault:"一行中的数字为5;
sed 's@\(id:\)[0-9]\(:initdefault:\)@\15\2@g' /etc/inittab
[root@Daniel-R480 ~]# cat /etc/inittab
# inittab is no longer used when using systemd.
#
# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
#
# systemd uses 'targets' instead of runlevels. By default, there are two main targets:
id:3:initdefault:
#
# multi-user.target: analogous to runlevel 3
# graphical.target: analogous to runlevel 5
#
# To view current default target, run:
# systemctl get-default
#
# To set a default target, run:
# systemctl set-default TARGET.target
#
[root@Daniel-R480 ~]# sed 's@\(id:\)[0-9]\(:initdefault:\)@\15\2@g' /etc/inittab
# inittab is no longer used when using systemd.
#
# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
#
# systemd uses 'targets' instead of runlevels. By default, there are two main targets:
id:5:initdefault:
3、删除/etc/inittab文件中的空白行;
sed '/^$/d' /etc/inittab
[root@Daniel-R480 ~]# cat !$
cat /etc/inittab
# inittab is no longer used when using systemd.
#
# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
#
# systemd uses 'targets' instead of runlevels. By default, there are two main targets:
id:3:initdefault:
#
# multi-user.target: analogous to runlevel 3
# graphical.target: analogous to runlevel 5
#
# To view current default target, run:
# systemctl get-default
#
# To set a default target, run:
# systemctl set-default TARGET.target
#
[root@Daniel-R480 ~]#
[root@Daniel-R480 ~]#
[root@Daniel-R480 ~]# sed '/^$/d' /etc/inittab
# inittab is no longer used when using systemd.
#
# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
4、删除/etc/inittab文件中开头的#号;
sed 's@^#@@g' /etc/inittab
[root@Daniel-R480 ~]# sed 's@^#@@g' /etc/inittab
inittab is no longer used when using systemd.
ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
systemd uses 'targets' instead of runlevels. By default, there are two main targets:
id:3:initdefault:
multi-user.target: analogous to runlevel 3
graphical.target: analogous to runlevel 5
To view current default target, run:
systemctl get-default
To set a default target, run:
systemctl set-default TARGET.target
5、删除某文件中开头的#号及后面的空白字符,但要求#号后面必须有空白字符;
sed -r 's@^#[[:space:]]+@@g' /etc/inittab
[root@Daniel-R480 ~]# sed -r 's@^#[[:space:]]+@@g' /etc/inittab
inittab is no longer used when using systemd.
#
ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
#
systemd uses 'targets' instead of runlevels. By default, there are two main targets:
id:3:initdefault:
#
multi-user.target: analogous to runlevel 3
graphical.target: analogous to runlevel 5
#
To view current default target, run:
systemctl get-default
#
To set a default target, run:
systemctl set-default TARGET.target
#
6、删除某文件中以空白字符后面跟#类的行中的开头的空白字符及#
sed -r 's@^[[:space:]]+#@@g' /etc/inittab
7、取出一个文件路径的目录名称;
echo "/etc/rc.d/" | sed -r 's@^(/.*/)[^/]+/?@\1@g'
基名:
echo "/etc/rc.d/" | sed -r 's@^/.*/([^/]+)/?@\1@g'
#abc
# hello world
# hi world
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