ocp-manager

ocp-manager is a tool to manage several versions of OCaml on the same computer. It is a useful complement to OPAM, to ease managing switches.

Interesting Features:

• Change the current switch without modifying the PATH variable.

• Force a switch for commands executed in a specific directory/project.

• Define default commands for commands missing in a switch.

Compilation and Installation

You need 'ocp-build' installed on your computer:

opam install ocp-build

Now, you can compile ocp-manager:

./configure
make
make install

You need to configure your PATH variable. You can add in your ~/bashrc (or whatever configure file for your shell):

eval `ocp-manager -config`

How to update

If you have a version of 'ocp-manager' before Feb 13. 2014, you should restore what it might have changed:

ocp-manager -restore

Usage

Managing Switches

Switches are directories containing OCaml binaries. For example, every OPAM switch is an ocp-manager switch. The distribution switch in /usr/bin is known as distrib in ocp-manager.

You can list available switches using:

ocp-manager -list

You can set the global switch to SWITCH using:

ocp-manager -set SWITCH

You can also set OCAML_VERSION in your terminal to just change the version of OCaml in a terminal or for a command:

OCAML_VERSION=opam:4.01.0 ocamlc -v

Managing Tools

You can see which tools in the current switch are managed by 'ocp-manager':

ocp-manager -tools

ocp-manager has a default list of tools. If some tool CMD is not managed by ocp-manager, you can use:

ocp-manager -add-tool CMD

You can also add all tools from the current switch:

ocp-manager -add-all

Of course, you can also stop ocp-manager from managing a tool CMD:

ocp-manager -remove-tool CMD

Managing Default Tools

If a tool is not available in the current switch, ocp-manager is going to check if a default tool is available. You can define your own default tools. For example, for ocp-indent:

ocp-manager -add-default /usr/local/bin/ocp-indent

/usr/local/bin/ocp-indent will now be used in all switches where `ocp-indent is not locally available.

You can also directly copy the executable:

cp /usr/local/bin/ocp-indent ~/.ocp/manager-defaults/

Compiling OCaml to a new Switch

To add a new version in the list, you just need to install a version of OCaml in $HOME/.ocp/manager-switches/ocaml-$VERSION/{bin,lib,man}. You can use:

ocp-manager -compile SOME-VERSION

in the sources of OCaml to compile and install a new version of OCaml, called SOME-VERSION in the list.

OPAM switches

ocp-manager can manage OPAM switches. Such switches should be prefixed with "opam:". For example, you can use "opam:3.12.1" for OPAM switch "3.12.1".

Be careful never to use opam config env, as this command will override the PATH variable and prevent ocp-manager from working.

Per-directory configuration

With ocp-manager, you can define a per-project switch: at the root of your project, create a file '.ocp-switch' containing the switch name, or '.opam-switch' containing the OPAM switch name.

For example, in a project typerex, I can have .ocp-switch containing opam:4.01.0, or .opam-switch containing 4.01.0, so that, whatever the configuration of OPAM and ocp-manager, I will always use 4.01.0 to compile this project.