anchor.diff:  // See https://hubpress.gitbooks.io/hubpress-knowledgebase/content/ for information about the parameters.
   // :hp-image: /covers/cover.png
   // :published_at: 2019-01-31
  -:hp-tags: Linux, Unix, REST
  +:hp-tags: Linux, Unix, REST, CLI, BASH
   // :hp-alt-title: My English Title
   
  -1. Construct your JSON variable.
  +If your REST URL looks like this:
  +....
  + http://some.server:8080/URI/TO/RESTful/API
  +....
  +
  +`1.` Construct your JSON variable.
   ....
   #No indentations otherwise heredoc may break.
   json=$(cat <<EOF
  
positive.code: # $json
  ....
  
  5. Show response and close connection.
  ....
   cat <&3
   exec 3<&-
  
negative.code: )
  ....
  
  `2.` Calculate Content-Length.
  ....
   len=${#json}
  ....
  
  `3.` Open TCP socket using descriptor (3).
  ....
  #exec 3<>/dev/tcp/SERVER/PORT
   exec 3<>/dev/tcp/some.server/8080
  ....
  
  `4.` ECHO spoofed header to descriptor (3).
  ....
  #This must be on 1 line.
   echo -e "POST /URI/TO/RESTful/API HTTP/1.1\r\nHost: some.server\r\nContent-type: application/json\r\nContent-length: $len\r\nConnection: close \r\n\r\n$json">&3
  