We recommend installing Links using the OPAM tool, available from opam.ocaml.org.
Links requires at least OCaml 4.08.0 to build and install. Therefore you should first install the minimum (or greater) required version of OCaml:
$ opam switch install 4.08.0
Next you should install the install the system dependencies for Links:
$ opam install depext
$ opam depext links
If you wish to use Links' database functionality, you also have to install one (or all) of database management systems that you wish to use on your system:
$ opam depext links-postgresql links-mysql links-sqlite3
You can then install Links and its database drivers simply by issuing the commands:
$ opam install links links-postgresql links-mysql links-sqlite3
Alternatively, if you don't have PostgreSQL installed then do:
$ opam install links
This will put Links and its files into your OPAM switch. The
environment variable $OPAM_SWITCH_PREFIX
points to your current
active switch. Links files install to several locations inside an OPAM
switch:
- The executable is called
linx
and goes into$OPAM_SWITCH_PREFIX/bin
- The Links prelude and JavaScript libraries go into
$OPAM_SWITCH_PREFIX/lib/links
- The example Links programs go into
$OPAM_SWITCH_PREFIX/share/links
- Links configuration file goes into
$OPAM_SWITCH_PREFIX/etc/links
Links supports running applications via a standalone application server.
To run the examples that don't use the database with the Links application server issue the following command:
$ linx --path=$OPAM_SWITCH_PREFIX/share/links/examples --path=$OPAM_SWITCH_PREFIX/share/links/examples/games $OPAM_SWITCH_PREFIX/share/links/examples/webserver/examples-nodb.links
(This version just displays the source code for examples that use the database.)
The default port is 8080, so you should now be able to access the examples by pointing your browser at:
To run the examples using the Links application server issue the following command:
$ linx --path=$OPAM_SWITCH_PREFIX/share/links/examples --path=$OPAM_SWITCH_PREFIX/share/links/examples/games --path=$OPAM_SWITCH_PREFIX/share/links/examples/dictionary $OPAM_SWITCH_PREFIX/share/links/examples/webserver/examples.links
- The
--path
option tells Links to look for source files in the following directories under$OPAM_SWITCH_PREFIX/share/links
:- examples
- examples/games
- examples/dictionary
- Finally examples/webserver/examples.links is the file to run, which imports the example modules and sets up the application server.
But first you need to do a few things.
-
By default Links uses a config file inside
$OPAM_SWITCH_PREFIX/etc/links
directory. Use--config=/custom/config/file
option to use a different configuration file. -
The default config file should contain paths to JavaScript libraries:
jsliburl=/lib/js jslibdir=$OPAM_SWITCH_PREFIX/lib/links/js
To use database examples you need to add a database configuration to the config file:
database_driver=postgresql database_args=localhost:5432:fred:
The database user fred should exist. With postgres, perhaps the easiest way to do this is to tie fred to your unix username and then no separate authentication is required.
-
Create appropriate databases. If you are using postgres and you have tied your username to the database as described in 2) then you can use the scripts in examples/dbsetup.
$ cd examples/dbsetup
./createdbs
./populatedbs
Otherwise you can adapt them to your particular database set up.
Postgres data dumps for the larger databases (citations and dictionary) can be obtained from a separate repository: https://github.com/links-lang/links-data.
For convenience you may want to add the path
to the config file
path=$OPAM_SWITCH_PREFIX/share/links/examples,$OPAM_SWITCH_PREFIX/share/links/examples/games,$OPAM_SWITCH_PREFIX/share/links/examples/dictionary
Then simply issue the following command to run the database examples application:
$ linx $OPAM_SWITCH_PREFIX/share/links/examples/webserver/examples.links
Some (outdated) documentation can be built by running the Makefile in the doc directory.
Some very incomplete documentation is available on the links wiki: