erl

Erl is a command line tool used for running and interacting with applications written in the Erlang programming language. Erlang is a concurrent, functional programming language designed for building distributed, fault-tolerant, and scalable systems.

When running the erl command, it starts an Erlang shell (also known as the "REPL" or "interpreter") where you can execute Erlang expressions, define functions, and work with Erlang modules in an interactive manner. The Erlang shell provides a fast development and testing environment for Erlang applications, allowing you to quickly experiment with code snippets or troubleshoot issues.

The erl command also accepts command-line arguments for different purposes, such as specifying the Erlang version, setting the node name for distributed Erlang communication, loading specific modules, passing runtime flags, and more.

In addition to the Erlang shell, erl can be used for running Erlang scripts, similar to other interpreted programming languages. You can pass the name of an Erlang script as an argument to erl, and it will execute the code in that file.

Erlang and the erl command are widely used in industries such as telecommunications, internet services, and real-time systems, where high availability and fault tolerance are critical requirements. The language's design and the tools like erl make it easy to build systems that can handle massive concurrency, distribute computation across multiple nodes, and recover from failures.