grep如何只抓取需要的字符 grep只输出匹配字符串

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mob64ca141a683a 2024-07-03 14:05:50

文章标签 grep如何只抓取需要的字符 openwrt cut sed 字符串 文章分类 云原生云计算

awk

详细参数说明awk '{print $3,$4}' /proc/net/arp 把arp文件的第三行和第四行，打印出来，可以重定向到文件

root@OpenWrt:/tmp# awk '{print $3,$4}' /proc/net/arp >/tmp/net_arp_list
root@OpenWrt:/tmp# cat net_arp_list 
HW type
0x2 28:ed:6a:e9:ab:fb
0x2 00:e0:4c:68:00:03
0x2 a4:44:d1:d6:d2:3f
root@OpenWrt:/tmp# cd /tmp/
root@OpenWrt:/tmp# ls
802.mt7603e.log        extroot                net_arp_list
802.mt7612e.log        fastcgi.socket-0       overlay

root@OpenWrt:/tmp# cat /proc/net/arp 
IP address       HW type     Flags       HW address            Mask     Device
192.168.0.30     0x1         0x2         28:ed:6a:e9:ab:fb     *        br-lan
192.168.0.188    0x1         0x2         00:e0:4c:68:00:03     *        br-lan
192.168.0.250    0x1         0x2         a4:44:d1:d6:d2:3f     *        br-lan
root@OpenWrt:/tmp# awk '{print $3,$4}' /proc/net/arp 
HW type
0x2 28:ed:6a:e9:ab:fb
0x2 00:e0:4c:68:00:03
0x2 a4:44:d1:d6:d2:3f

awk -F ‘:’，以冒号为分隔符

root@OpenWrt:/tmp# cat Update_status 
version=2
=0.0.99
DTBVersion=
remote=9
IDUVersion=0.0.99
DTBVersion=
root@OpenWrt:/tmp# cat Update_status | grep IDUVersion 
IDUVersion=0.0.99
root@OpenWrt:/tmp# cat Update_status | grep IDUVersion | awk -F '=' '{print $2}'
0.0.99
root@OpenWrt:/tmp# 
root@OpenWrt:/tmp#

root@OpenWrt:~# 
root@OpenWrt:~# cat /tmp/Update_status 
version=2
remote=9
remote=9
IDUVersion=0.0.99
IDUVersion=0.0.99
DTBVersion=
DTBVersion=
root@OpenWrt:~# cat /tmp/Update_status | grep IDUVersion 
IDUVersion=0.0.99
IDUVersion=0.0.99
root@OpenWrt:~# 
root@OpenWrt:~# cat /tmp/Update_status | grep IDUVersion | awk -F '=' '{print $2}' 
0.0.99
0.0.99
root@OpenWrt:~# cat /tmp/Update_status | grep IDUVersion | awk -F '=' '{print $2}' | awk 'NR==1 {print}'
0.0.99
root@OpenWrt:~# 
root@OpenWrt:~# 
root@OpenWrt:~# cat /tmp/Update_status | grep IDUVersion | awk -F '=' 'NR==1 {print $2}' 
0.0.99
root@OpenWrt:~#

NR - Number of Record - 当前处理的行是第几行（因为awk是流处理工具，一行一行处理的，所以NR在不停的自增1)
FNR - File Number of Record - 当前处理的行是当前处理文件的第几行
NF - Number of Fileds - 当前行有多少列数据（这个在每行都会根据设定的分割符重新计算，默认分割符是任意连续的多个空白符）

cut

详细参数说明 cut -d ‘空格’ -f 1
以 ‘空格’ 为分隔符，选取第一个域里面的内容，输出

root@OpenWrt:/tmp# grep "28:ed:6a:e9:ab:fb" /tmp/net_arp_list 
0x2 28:ed:6a:e9:ab:fb
root@OpenWrt:/tmp# grep "28:ed:6a:e9:ab:fb" /tmp/net_arp_list | cut -d ' ' -f 1
0x2
root@OpenWrt:/tmp#

将一行内容，去回车，拼成字符串
40007: 65
40008: 43
40009: 21
拼成：654321

root@OpenWrt:~# flash  -r 0x40007 -c 3 | awk '{print $2}' | sed ':a ; N;s/\n// ;t a ;'
654321
root@OpenWrt:~# flash  -r 0x40007 -c 3 
40007: 65
40008: 43
40009: 21
root@OpenWrt:~# flash  -r 0x40007 -c 3 | awk '{print $2}' 
65
43
21
root@OpenWrt:~# flash  -r 0x40007 -c 3 | awk '{print $2}' | sed ':a ; N;s/\n// ;t a ;'
654321
root@OpenWrt:~#

sed

http://man.linuxde.net/sed

1.sed 匹配字段后,在其前后,添加文本方法

sed -i “/匹配字段/i\加上想要插入到匹配字段前一行的内容” 文件名
红色的i是添加到前面，a是添加到后面

root@OpenWrt:~# cat /etc/config/8192eewpa 
ctrl_interface_group=0
ap_scan=1
network={
        ssid="lin"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        psk="11223355"
}
root@OpenWrt:~# sed -i "/psk/i\        bssid=11.22.33" /etc/config/8192eewpa 
root@OpenWrt:~# cat /etc/config/8192eewpa 
ctrl_interface_group=0
ap_scan=1
network={
        ssid="lin"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        bssid=11.22.33
        psk="11223355"
}
root@OpenWrt:~#

2.替换某行的内容

把第9行的内容替换为" 空格 bssid=22.33.44.55.66"

sed -i '9c\        bssid=22.33.44.55.66' /etc/config/8192eewpa

举例：

root@OpenWrt:~# cat /etc/config/8192eewpa 
ctrl_interface_group=0
ap_scan=1
network={
        ssid="lin"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        bssid=11.22.33.44.55
        psk="11223355"
}
root@OpenWrt:~# 
root@OpenWrt:~#  sed -i '9c\        bssid=22.33.44.55.66' /etc/config/8192eewpa   
root@OpenWrt:~# 
root@OpenWrt:~# cat /etc/config/8192eewpa 
ctrl_interface_group=0
ap_scan=1
network={
        ssid="lin"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        bssid=22.33.44.55.66
        psk="11223355"
}
root@OpenWrt:~#

3.删除匹配行和替换

替换匹配行

sed -i 's/要匹配的字符串.*/替换为的字符串/g' demo

-i 表示操作在源文件上生效

root@OpenWrt:/etc/uplink# cat test1
ctrl_interface_group=0
ap_scan=1
network={
        ssid=bbbbbbbb
        proto=RSN
        key_mgmt=NONE
}


root@OpenWrt:/etc/uplink# sed  's/ssid=.*/ssid='eeeeee'/g' test1
ctrl_interface_group=0
ap_scan=1
network={
        ssid=eeeeee
        proto=RSN
        key_mgmt=NONE
}


root@OpenWrt:/etc/uplink#

删除以a开头的行

sed -i '/^a.*/d' tmp.txt

替换文件中的某个字符串为替它字符串

文件内容：
#ukui embedded 的config.
#当Key是response，value是true时响应Windows按钮按键，false则不响应
[winKeyResponse]
response=true
--------------------------------------------
命令：
sed  "/^response/c response=false"  /etc/ukui/lite-config/ukui_menu_config.ini

备注：#替换文件/etc/ukui/lite-config/ukui_menu_config.ini中的response=true为response=false。加^表示行首
--------------------------------------------
执行后：
#ukui embedded 的config.
#当Key是response，value是true时响应Windows按钮按键，false则不响应
[winKeyResponse]
response=false

删除一个字符串中的部分字符

root@OpenWrt:/proc/wlan0# cat /tmp/dhcp.leases  | awk '{print $3,$4,$2}' 
192.168.1.181 iPhone 28:ed:6a:e9:ab:fb
192.168.1.109 lin-iPhone 90:e1:7b:1c:b1:4b
192.168.1.126 blin-pc1 f6:08:0b:0a:e0:78
root@OpenWrt:/proc/wlan0# cat /tmp/dhcp.leases  | awk '{print $3,$4,$2}' | sed 's/://g'
192.168.1.181 iPhone 28ed6ae9abfb
192.168.1.109 lin-iPhone 90e17b1cb14b
192.168.1.126 blin-pc1 f6080b0ae078
root@OpenWrt:/proc/wlan0#

如果想把一个字符串中的一些字符删除可以如此：
#Echo “2006-11-21 22:16:30” | sed ‘s/-//g’ | sed ‘s/ //g’ | sed ‘s/://g’
得到的结果就是：20061121221630
http://blog.chinaunix.net/uid-71729-id-114582.html

-i 表示操作在源文件上生效.否则操作内存中数据,并不写入文件中.
在分号内的/d表示删除匹配的行

在文件中查找指定的字符串，找到后打印出行号

grep -rn 'psk'  /etc/config/8192eewpa  | awk -F ':' '{print $1}'

举例：

root@OpenWrt:~# cat /etc/config/8192eewpa 
ctrl_interface_group=0
ap_scan=1
network={
        ssid="lin"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        bssid=11.22.33
        psk="11223355"
}
root@OpenWrt:~# grep -rn "psk" /etc/config/8192eewpa 
10:        psk="11223355"
root@OpenWrt:~# grep -rn 'psk'  /etc/config/8192eewpa  | awk -F ':' '{print $1}'
10

WC
1.查看文件有多少行

root@OpenWrt:/etc/config# cat /tmp/dhcp_list_file
192.168.1.181 iPhone 01:28:ed:6a:e9:ab:fb
192.168.1.108 blin-pc1 01:16:ae:ca:dc:84:5a
root@OpenWrt:/etc/config#  wc -l /tmp/dhcp_list_file
2 /tmp/dhcp_list_file
root@OpenWrt:/etc/config# wc -l /tmp/dhcp_list_file | awk '{print $1}'
2
root@OpenWrt:/etc/config#

shell脚本修改xml文件

#!/bin/bash

#修改设置关闭特效需要修改qt5-ukui-platformtheme-lite包的libqt5-ukui-style1的xml值
if [ -f /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml ]; then
    MenuNum=`cat /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml | grep -n menu-transparency | awk -F ':' '{print $1}' `

        if [ -z "$MenuNum" ]; then
                echo "-------The value is not present in the current file MenuNum---------"
                exit 0
        else
                echo "menunum:$MenuNum................."
        fi

        ModifyNum=$(($MenuNum+1))
    	echo "ModifyNum:$ModifyNum................."
        #将第N替换为<default>100</default>
        #sudo sed  -i "${ModifyNum} <default>100</default>"      /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml

        #c\添加空格。将第N替换为： 空格或tab <default>100</default>
        sudo sed  -i "${ModifyNum}c\    <default>100</default>"      /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml
fi

if [ -f /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml ]; then
    PeonyNum=`cat /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml | grep -n peony-side-bar-transparency | awk -F ':' '{print $1}' `

        if [ -z "$PeonyNum" ]; then
                echo "-------The value is not present in the current file PeonyNum---------"
                exit 0
        else
                echo "PeonyNum:$PeonyNum................."
        fi

        ModifyPeonyNum=$(($PeonyNum+1))
    	echo "ModifyPeonyNum:$ModifyPeonyNum................."
        sudo sed  -i "${ModifyPeonyNum}c\       <default>100</default>"      /usr/share/glib-2.0/schemas/org.ukui.style.gschema.xml
fi

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