How To Install libre2j-java on Debian 12
Introduction
In this tutorial we learn how to install libre2j-java on Debian 12.
What is libre2j-java
libre2j-java is:
RE2 is a regular expression engine that runs in time linear in the size of the input. RE2/J is a port of RE2 to pure Java.
Java’s standard regular expression package, java.util.regex, and many other widely used regular expression packages such as PCRE, Perl and Python use a backtracking implementation strategy: when a pattern presents two alternatives such as a|b, the engine will try to match subpattern a first, and if that yields no match, it will reset the input stream and try to match b instead.
If such choices are deeply nested, this strategy requires an exponential number of passes over the input data before it can detect whether the input matches. If the input is large, it is easy to construct a pattern whose running time would exceed the lifetime of the universe. This creates a security risk when accepting regular expression patterns from untrusted sources, such as users of a web application.
In contrast, the RE2 algorithm explores all matches simultaneously in a single pass over the input data by using a nondeterministic finite automaton.
There are certain features of PCRE or Perl regular expressions that cannot be implemented in linear time, for example, backreferences, but the vast majority of regular expressions patterns in practice avoid such features.
There are three methods to install libre2j-java on Debian 12. We can use apt-get, apt and aptitude. In the following sections we will describe each method. You can choose one of them.
Install libre2j-java Using apt-get
Update apt database with apt-get using the following command.
sudo apt-get update
After updating apt database, We can install libre2j-java using apt-get by running the following command:
sudo apt-get -y install libre2j-java
Install libre2j-java Using apt
Update apt database with apt using the following command.
sudo apt update
After updating apt database, We can install libre2j-java using apt by running the following command:
sudo apt -y install libre2j-java
Install libre2j-java 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 libre2j-java using aptitude by running the following command:
sudo aptitude -y install libre2j-java
How To Uninstall libre2j-java on Debian 12
To uninstall only the libre2j-java package we can use the following command:
sudo apt-get remove libre2j-java
Uninstall libre2j-java And Its Dependencies
To uninstall libre2j-java and its dependencies that are no longer needed by Debian 12, we can use the command below:
sudo apt-get -y autoremove libre2j-java
Remove libre2j-java Configurations and Data
To remove libre2j-java configuration and data from Debian 12 we can use the following command:
sudo apt-get -y purge libre2j-java
Remove libre2j-java configuration, data, and all of its dependencies
We can use the following command to remove libre2j-java configurations, data and all of its dependencies, we can use the following command:
sudo apt-get -y autoremove --purge libre2j-java
Dependencies
libre2j-java have the following dependencies:
References
Summary
In this tutorial we learn how to install libre2j-java package on Debian 12 using different package management tools: apt, apt-get and aptitude.
