How To Install flex-old on Debian 9

In this tutorial we learn how to install flex-old on Debian 9. flex-old is Old version of the fast lexical analyzer generator

Introduction

In this tutorial we learn how to install flex-old on Debian 9.

What is flex-old

flex-old is:

flex is a tool for generating scanners: programs which recognize lexical patterns in text. This is the old 2.5.4a version, which is no longer being developed. You should normally choose flex, unless you have legacy lexer files that do not work with a modern flex.

This product includes software developed by the University of California, Berkeley and its contributors. The upstream source code can be found at http://flex.sourceforge.net/

There are three methods to install flex-old on Debian 9. We can use apt-get, apt and aptitude. In the following sections we will describe each method. You can choose one of them.

Install flex-old Using apt-get

Update apt database with apt-get using the following command.

sudo apt-get update

After updating apt database, We can install flex-old using apt-get by running the following command:

sudo apt-get -y install flex-old

Install flex-old Using apt

Update apt database with apt using the following command.

sudo apt update

After updating apt database, We can install flex-old using apt by running the following command:

sudo apt -y install flex-old

Install flex-old Using aptitude

If you want to follow this method, you might need to install aptitude first since aptitude is usually not installed by default on Debian. Update apt database with aptitude using the following command.

sudo aptitude update

After updating apt database, We can install flex-old using aptitude by running the following command:

sudo aptitude -y install flex-old

How To Uninstall flex-old on Debian 9

To uninstall only the flex-old package we can use the following command:

sudo apt-get remove flex-old

Uninstall flex-old And Its Dependencies

To uninstall flex-old and its dependencies that are no longer needed by Debian 9, we can use the command below:

sudo apt-get -y autoremove flex-old

Remove flex-old Configurations and Data

To remove flex-old configuration and data from Debian 9 we can use the following command:

sudo apt-get -y purge flex-old

Remove flex-old configuration, data, and all of its dependencies

We can use the following command to remove flex-old configurations, data and all of its dependencies, we can use the following command:

sudo apt-get -y autoremove --purge flex-old

Dependencies

flex-old have the following dependencies:

References

Summary

In this tutorial we learn how to install flex-old package on Debian 9 using different package management tools: apt, apt-get and aptitude.