Server nodejs

sous powershell 

> $env:PORT="8000"    

> echo $env:PORT      

8000

const http = require('http')

const port =  process.env.PORT;

const server = http.createServer((reqres=> {
  res.statusCode = 200
  res.setHeader('Content-Type''text/html')
  res.end('<h1>Hello, World!</h1>')
})

server.listen(port, () => {
  console.log(`Server running at port ${port}`)
})
In Windows Command-Prompt the syntax is 
>set PORT="8000"  
>echo %POST% 
 To get a list of all environment variables enter the command set To send those variables to a text file enter the command set > filename.txt