How To Install flex on Ubuntu 22.04
Introduction
In this tutorial we learn how to install flex
on Ubuntu 22.04.
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 Ubuntu 22.04. 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 Ubuntu. 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 Ubuntu 22.04
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 Ubuntu 22.04, we can use the command below:
sudo apt-get -y autoremove flex
Remove flex Configurations and Data
To remove flex
configuration and data from Ubuntu 22.04 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
References
Summary
In this tutorial we learn how to install flex
package on Ubuntu 22.04 using different package management tools: apt
, apt-get
and aptitude
.