i have a xml that i want to parse into csv, like i started to work with awk, i would like to continue with it but i know it is possible to do it with over language like perl also i found xmlstarlet but i don't have permission to install on server so i'am open on over solutions.
So my iinput xml is 

```
<?xml version="1.0"?>
<root>
  <record>
   <id_client>50C</id_client>  
  <data>
          <mail>1@mail.com</mail>
          <adress>10  </adress>
          <num_tel>001</num_tel>
          <key>C</key>
      <contact>
        <name>toto</name>
        <birth>01/30/009</birth>
        <city>London</city>
      </contact>
  </data> 
  <data>
          <mail>2@gmaiil.com</mail>
          <adress>20</adress>
          <num_tel>02200</num_tel>
          <key>D1</key>
      <contact>
        <name>tata</name>
        <birth>02/08/2004</birth>
        <city>Bruges</city>
      </contact>
  </data> 
</record>
   <record>
   <id_client>70D</id_client>  
  <data>
          <mail>3@gmail.com</mail>
          <adress>7Bcd</adress>
          <num_tel>5555</num_tel>
          <key>D2</key>
      <contact>
        <name>titi</name>
        <birth>05/07/2014</birth>
        <city>Paris</city>
      </contact>
  </data>
  <data>
          <mail>4@gmail.com</mail>
          <adress>888</adress>
          <num_tel>881.0</num_tel>
          <key>D3</key>
      <contact>
        <name>awk</name>
        <birth>05/08/1999</birth>
        <city>Lisbone</city>
      </contact>
  </data>

```

I would like to output in an over file this csv with hearders

```
id_client;mail;num_tel;key 
50C;1@mail.com;001;C
50C,2@gmail.com;02200;D1
70D;3@gmail.com;5555;D2 
70D;4@gmail.com;881.0;D3

```