OCamlrun

The ocamlrun command is the OCaml runtime system interpreter, used to execute OCaml bytecode executables (.byte files). It provides a way to run compiled OCaml programs without needing the native compiler. This tool is essential for deploying and running OCaml applications, especially in environments where native compilation is not feasible or desired.

Running OCaml Bytecode Executables

The most basic usage of ocamlrun is to simply provide the bytecode file as an argument:

ocamlrun my_program.byte

Controlling Runtime Behavior with OCAMLRUNPARAM

The OCAMLRUNPARAM environment variable allows fine-grained control over the OCaml runtime's behavior. This is particularly useful for managing memory, garbage collection, and other runtime aspects. For instance, you can set the stack size or enable specific garbage collector options:

OCAMLRUNPARAM='s=256k,v=0x40000' ocamlrun my_program.byte

Here, s=256k sets the stack size, and v=0x40000 might enable a specific runtime feature or flag.

Passing Arguments to OCaml Programs

You can pass command-line arguments to your OCaml bytecode program directly after the program name. These arguments will be accessible within your OCaml program via the Sys.argv array.

ocamlrun my_program.byte arg1 arg2 arg3

Displaying Help Information

To get help on the ocamlrun command itself, you can use the -help flag:

ocamlrun -help

Debugging OCaml Bytecode

For debugging purposes, you can enable the bytecode interpreter's debugging options by setting the b flag in OCAMLRUNPARAM. This can help in diagnosing issues during program execution.

OCAMLRUNPARAM=b ocamlrun my_debuggable_program.byte

Specifying Heap Size

For memory-intensive applications, you might need to specify a larger heap size. This can be done using the h parameter within OCAMLRUNPARAM.

OCAMLRUNPARAM='h=500M' ocamlrun memory_intensive_program.byte

This command allocates 500 megabytes of heap space for the OCaml program.

OCamlrun - Execute OCaml Bytecode Programs