How To Install flex on Debian 11
Introduction
In this tutorial we learn how to install flex on Debian 11.
What is flex
flex is:
Flex is a tool for generating scanners: programs which recognized lexical patterns in text. It reads the given input files for a description of a scanner to generate. The description is in the form of pairs of regular expressions and C code, called rules. Flex generates as output a C source file, lex.yy.c, which defines a routine yylex(). This file is compiled and linked with the -lfl library to produce an executable. When the executable is run, it analyzes its input for occurrences of the regular expressions. Whenever it finds one, it executes the corresponding C code.
There are three methods to install flex on Debian 11. 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 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 using apt-get by running the following command:
sudo apt-get -y install flex
Install flex Using apt
Update apt database with apt using the following command.
sudo apt update
After updating apt database, We can install flex using apt by running the following command:
sudo apt -y install flex
Install flex 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 using aptitude by running the following command:
sudo aptitude -y install flex
How To Uninstall flex on Debian 11
To uninstall only the flex package we can use the following command:
sudo apt-get remove flex
Uninstall flex And Its Dependencies
To uninstall flex and its dependencies that are no longer needed by Debian 11, we can use the command below:
sudo apt-get -y autoremove flex
Remove flex Configurations and Data
To remove flex configuration and data from Debian 11 we can use the following command:
sudo apt-get -y purge flex
Remove flex configuration, data, and all of its dependencies
We can use the following command to remove flex configurations, data and all of its dependencies, we can use the following command:
sudo apt-get -y autoremove --purge flex
Dependencies
flex have the following dependencies:
References
Summary
In this tutorial we learn how to install flex package on Debian 11 using different package management tools: apt, apt-get and aptitude.