raku

The Raku programming language interpreter

TLDR

Start an interactive REPL session

$ raku

Execute a Raku script

$ raku [path/to/script.raku]

Run a one-liner program

$ raku -e 'say "Hello, World!"'

Check the syntax of a script without executing it

$ raku -c [path/to/script.raku]

Run a program for each line of input (like awk/sed)

$ cat [path/to/file] | raku -ne 'say .uc'

Run a one-liner that also prints each line after processing

$ cat [path/to/file] | raku -pe '.=uc'

Add a module search path and load a module before execution

$ raku -I [lib] -M [MyModule] [path/to/script.raku]

Extract and display inline Pod documentation

$ raku --doc [path/to/script.raku]

SYNOPSIS

raku [switches] [--] [programfile] [arguments]

raku is the interpreter for the Raku programming language (formerly known as Perl 6). Raku is a multi-paradigm language supporting procedural, object-oriented, functional, and concurrent programming. It features gradual typing, powerful pattern matching with grammars, built-in concurrency primitives, and Unicode support throughout.When invoked without arguments, raku starts an interactive REPL (Read-Eval-Print Loop). With a program file or the -e option, it compiles and executes the given code. The -n and -p flags provide awk/sed-like one-liner capabilities for processing input line by line.The interpreter is implemented by Rakudo, the primary Raku compiler, which targets the MoarVM virtual machine (and optionally JVM). Raku scripts conventionally use the .raku file extension (previously .p6 or .pl6).

PARAMETERS

-c

Check syntax only (runs BEGIN and CHECK blocks but does not execute the program).

-e program

Execute one line of program. Strict mode is enabled by default.

-n

Run the program once for each line of input.

-p

Same as -n, but also prints $_ at the end of each line.

-I path

Add path to the module search path.

-M module

Load module before running the program.

-o, --output name

Specify the name of the output file for compilation.

-h, --help

Display help text.

-v, --version

Display version information.

-V

Print configuration summary.

--doc[=module]

Extract inline Pod documentation and print as text. Optionally use Pod::To::module to render (e.g. --doc=HTML).

--target stage

Specify the compilation stage to emit (parse, ast, mast, mbc).

--optimize level

Set optimization level (0 to 3).

--rakudo-home path

Override the path to Rakudo runtime files.

--stagestats

Display time spent in each compilation stage.

--ll-exception

Display a low-level backtrace on errors.

--profile[=name]

Write profile information to a file. Format determined by extension (.json, .sql, or .html).

--profile-compile[=name]

Write compile-time profile information to a file.

--full-cleanup

Try to free all memory and exit cleanly.

--debug-port port

Listen for incoming debugger connections on port.

--debug-suspend

Pause execution at the entry point.

CAVEATS

Startup time can be noticeably slower than Perl 5 or Python due to compilation overhead. The -c flag runs BEGIN and CHECK blocks, so syntax checking is not entirely side-effect-free. Module ecosystem is smaller than Perl 5's CPAN. The --profile option can generate very large output files for long-running programs.

HISTORY

Raku began as Perl 6, announced by Larry Wall in 2000 as a complete redesign of the Perl language. After nearly two decades of development, the first stable release (Rakudo Star 2015.12) shipped in December 2015. In October 2019, the language was officially renamed from Perl 6 to Raku to establish its own identity separate from Perl 5. The primary implementation is Rakudo, running on the MoarVM virtual machine.