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如何从一个文件中提取字符串以插入（修改）到另一个文件中？

tag-icon • tag-icon grep php xml pcre
如何从一个文件中提取字符串以插入（修改）到另一个文件中？

问题如下：

我有一个包含数据的 xml 文件，我正在寻找一小部分数据将其写入新文件：内容已根据请求缩短：

如果 type=dhcp-client，则代码片段：

    <deviceconfig>
      <system>
        <type>
          <dhcp-client>
            <send-hostname>yes</send-hostname>
          </dhcp-client>
        </type>
        <hostname>Firewall</hostname>
      </system>
    </deviceconfig>

如果 type=static 则片段

    <deviceconfig>
      <system>
        <type>
          <static/>
        </type>
        <hostname>Firewall</hostname>
        <permitted-ip>
          <entry name="192.168.0.0/24"/>
        </permitted-ip>
        <ip-address>192.168.0.2</ip-address>
        <netmask>255.255.255.0</netmask>
        <default-gateway>192.168.0.1</default-gateway>
      </system>
    <network>
      <interface>
        <ethernet>
          <entry name="ethernet1/1">
            <layer3>
              <ip>
                <entry name="192.168.0.5/24"/>
              </ip>
            </layer3>
          </entry>
        </ethernet>
      </interface>
      <virtual-router>
        <entry name="default">
          <routing-table>
            <ip>
              <static-route>
                <entry name="default-route">
                  <nexthop>
                    <ip-address>192.168.0.1</ip-address>
                  </nexthop>
                  <interface>ethernet1/4</interface>
                  <destination>0.0.0.0/0</destination>
                </entry>
              </static-route>
            </ip>
          </routing-table>
        </entry>
      </virtual-router>
    </network>

四个相关值在“系统”标签内是唯一的（或不存在）， <system></system> 像IP地址之类的东西可能会再次出现在系统之外的其他地方， <system></system> 但我只检查系统内部的值，如果类型不是静态的，则不会出现，我会设置它到 dhcp 客户端

如果类型是 dhcp，这就是我需要的文件结果：

type=dhcp-client

如果类型是静态的，这就是我在文件中需要的结果：

type=static
ip-address=192.168.0.2
default-gateway=192.168.0.1
netmask=255.255.255.0

我不确定如何有效地完成此任务并将其集成到现有的PHP文件（所以要么使用 exec 工作，要么最好只使用 php）。

我还只能使用 ubuntu 服务器系统上默认安装的工具，并且无法使用其他软件包。

PS：这实际上是整个/完整的用例，除了这两个示例之外，我不需要生成其他输出。感谢您的帮助或指点:)

答案1

假设您无法访问 XML 感知工具，并且您的输入文件如您所示的那样简单且规则，这会根据您发布的示例输入生成预期的输出：

$ cat tst.awk
BEGIN { FS="[[:space:]]*[<>][[:space:]]*"; OFS="=" }
$2 == "system"  { inBlock=1 }
inBlock { f[$2] = $3 }
$2 == "/system" { inBlock=0 }
END {
    if ("ip-address" in f) {
        print "type", "static"
        print "ip-address", f["ip-address"]
        print "default-gateway", f["default-gateway"]
        print "netmask", f["netmask"]
    }
    else {
        print "type", "dhcp-client"
    }
}

。

$ awk -f tst.awk absentFile
type=dhcp-client

。

$ awk -f tst.awk presentFile
type=static
ip-address=192.168.0.2
default-gateway=192.168.0.1
netmask=255.255.255.0

以上是在这些输入文件上运行的：

$ tail -n +1 absentFile presentFile
==> absentFile <==
    <deviceconfig>
      <system>
        <type>
          <dhcp-client>
            <send-hostname>yes</send-hostname>
          </dhcp-client>
        </type>
        <hostname>Firewall</hostname>
      </system>
    </deviceconfig>

==> presentFile <==
    <deviceconfig>
      <system>
        <type>
          <static/>
        </type>
        <hostname>Firewall</hostname>
        <permitted-ip>
          <entry name="192.168.0.0/24"/>
        </permitted-ip>
        <ip-address>192.168.0.2</ip-address>
        <netmask>255.255.255.0</netmask>
        <default-gateway>192.168.0.1</default-gateway>
      </system>
    <network>
      <interface>
        <ethernet>
          <entry name="ethernet1/1">
            <layer3>
              <ip>
                <entry name="192.168.0.5/24"/>
              </ip>
            </layer3>
          </entry>
        </ethernet>
      </interface>
      <virtual-router>
        <entry name="default">
          <routing-table>
            <ip>
              <static-route>
                <entry name="default-route">
                  <nexthop>
                    <ip-address>192.168.0.1</ip-address>
                  </nexthop>
                  <interface>ethernet1/4</interface>
                  <destination>0.0.0.0/0</destination>
                </entry>
              </static-route>
            </ip>
          </routing-table>
        </entry>
      </virtual-router>
    </network>

答案2

好吧，我自己找到了答案......

实际上，在 php 中比没有它简单得多......

不过我确实花了很多小时才完成^^

#load the file as simplexml object and then switch into system
#https://www.w3schools.com/php/func_simplexml_load_file.asp
$xml=simplexml_load_file('./myfile') or die("Error: Cannot create object");
$xml=$xml->system

#put the whole string(s) into a variable, getname gets the name of the object itself if it exists
#https://www.w3schools.com/php/func_simplexml_getname.asp
$output='type=' . $xml -> type -> static -> getName() . $xml -> type -> {'dhcp-client'} -> getName() . "\nip-address=" . $xml -> {'ip-address'} . "\ndefault-gateway=" . $xml -> {'default-gateway'} . "\nnetmask=" . $xml -> netmask;

#write the output into a file
#https://www.w3schools.com/php/func_filesystem_file_put_contents.asp
file_put_contents('./myoutputfile', $output );

这为我提供了第一个片段的以下输出（如果最后三行没有给出值，则可以，否则我可以先检查它们是否存在）：

type=dhcp-client
ip-address=
default-gateway=
netmask=

第二个片段的输出：

type=static
ip-address=192.168.0.2
default-gateway=192.168.0.1
netmask=255.255.255.0

感谢大家的帮助:)

答案3

您可以使用以下脚本ip-parse.sh：

#!/bin/bash

#https://stackoverflow.com/questions/22221277/bash-grep-between-two-lines-with-specified-string
#https://www.cyberciti.biz/faq/bash-remove-whitespace-from-string/
#https://stackoverflow.com/questions/1251999/how-can-i-replace-a-newline-n-using-sed
sed -n '/\<system\>/,/system\>/p' ~/Desktop/x-test.xml | sed -e 's/^[ \t]*//' > ~/Desktop/x-system.xml
sed ':a;N;$!ba;s/\n/ /g' ~/Desktop/x-system.xml > /tmp/xml-one-line.xml

#[]test to see if the "system" section ...
#... has the word hostname occuring before the word ip-address    
#https://stackoverflow.com/questions/33265650/grep-for-a-string-in-a-specific-order
if [ -n "$(grep hostname.*ip-address /tmp/xml-one-line.xml)" ]; then 
    echo "File contains hostname and ip-address, in that order."
else
    echo "type=dhcp-client" ; echo "type=dhcp-client" > ~/Desktop/network-config.txt ; exit
fi

#http://www.compciv.org/topics/bash/variables-and-substitution/    
ipaddress="$(grep ip-address ~/Desktop/x-system.xml | sed 's/<ip-address>//g; s/<\/ip-address>//g')"  
defaultgateway="$(grep default-gateway ~/Desktop/x-system.xml | sed 's/<default-gateway>//g; s/<\/default-gateway>//g')"
netmask="$(grep netmask ~/Desktop/x-system.xml | sed 's/<netmask>//g; s/<\/netmask>//g')"

echo "type=static" > ~/Desktop/network-config.txt
echo "ip-address=$ipaddress" >> ~/Desktop/network-config.txt
echo "default-gateway=$defaultgateway" >> ~/Desktop/network-config.txt
echo "netmask=$netmask" >> ~/Desktop/network-config.txt

Application example:

paul@mxg6:~/Desktop$ ./ip-parse.sh   
File contains hostname and ip-address, in that order.  
paul@mxg6:~/Desktop$ cat network-config.txt   
type=static  
ip-address=192.168.0.2  
default-gateway=192.168.0.1  
netmask=255.255.255.0

如果您不需要检查主机名是否在 ip 地址之前，并且您想使用变量而不是中间文件，请尝试以下操作：

#!/bin/bash

xsystemxml="$(sed -n '/\<system\>/,/system\>/p' ~/Desktop/x-test.xml \
| sed -e 's/^[ \t]*//')"

if [ -n "$(echo $xsystemxml | grep ip-address)" ]; then 
    echo "System section contains ip-address."
else
    echo "type=dhcp-client"
    echo "type=dhcp-client" > ~/Desktop/network-config.txt
    exit
fi

ipaddress="$(echo "$xsystemxml" | grep "ip-address" \
| sed 's/<ip-address>//g; s/<\/ip-address>//g')"

defaultgateway="$(echo "$xsystemxml" | grep "default-gateway" \
| sed 's/<default-gateway>//g; s/<\/default-gateway>//g')"

netmask="$(echo "$xsystemxml" | grep "netmask" \
| sed 's/<netmask>//g; s/<\/netmask>//g')"

echo "type=static" > ~/Desktop/network-config.txt
echo "ip-address=$ipaddress" >> ~/Desktop/network-config.txt
echo "default-gateway=$defaultgateway" >> ~/Desktop/network-config.txt
echo "netmask=$netmask" >> ~/Desktop/network-config.txt

答案4

以下答案来自这里https://stackoverflow.com/questions/893585/how-to-parse-xml-in-bash，我做了一个简单的脚本

#!/bin/bash

read_dom () {
    local IFS=\>
    read -d \< ENTITY CONTENT
}

found=0
while read_dom; do
    if [[ $ENTITY = "ip-address" ]] && [[ $last_tag = "/hostname" ]] || [[ $ENTITY = "netmask" ]] || [[ $ENTITY = "default-gateway" ]]; then
        if [[ $found = 0 ]]; then
            echo "type=static"
        fi

        echo "$ENTITY=$CONTENT"
        found="1"
    fi
    last_tag=$ENTITY
done

if [[ $found = 0 ]]; then
    echo "type=dhcp-client"
fi

如果你给你的脚本命名parse.sh，你就可以这样称呼它

parse.sh < input.xml > output.txt

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