Where's the Unix library?

I’m using ocaml 4.12.0 on a Mac, and the Unix standard library doesn’t appear to exist. For example, typing “Unix.time;;” to the prompt results in “Error: Reference to undefined global `Unix’”. Do I need to do something to load it?

If you are using dune, remember to add unix as a dependency. If you aren’t using dune make sure you add the UNIX.cma as described here: The Unix Module

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Yes: you can load it by passing the name of the .cma archive on the command line, eg: ocaml unix.cma.


Thank you. That solves the problem when I’m running ocaml interactively.

Thank you. That solves the problem when I’m compiling the ocaml program.

Interactively, you may also use the directive #load "unix.cma";; if you didn’t put it initially on the command line and don’t want to restart the toplevel.