stunnel3 command not found

Introduction

When you run more command in linux terminal / console, you get the following error message

stunnel3: command not found

or when using sudo you get the following error message

sudo: stunnel3: command not found

Solutions to stunnel3: command not found

How To Fix stunnel3: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu stunnel3 is provided by stunnel4 package.

stunnel4 is:

The stunnel program is designed to work as SSL encryption wrapper between remote client and local (inetd-startable) or remote server. The concept is that having non-SSL aware daemons running on your system you can easily setup them to communicate with clients over secure SSL channel.

stunnel can be used to add SSL functionality to commonly used inetd daemons like POP-2, POP-3 and IMAP servers without any changes in the programs’ code.

This package contains a wrapper script for compatibility with stunnel 3.x

To fix this problem, we can install more using the command below.

sudo apt-get -y install stunnel4

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install stunnel4.

sudo apt -y install stunnel4

Or if you have aptitude installed you can use the following command.

sudo aptitude install stunnel4

Summary

In this tutorial we learn how to fix stunnel3 command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.