Online Judge plugin for Moodle.
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This plugin is in BETA version and NOT recommended to use in production sites

README varies in respect to version, check branches to view all the available versions.


The Online Judge 3 plugin for Moodle 3 (there are older versions) is designed for courses involving programming. It can automatically grade submitted source code by testing them against customizable test cases (ACM-ICPC/Online Judge style).

It contains three modules:

  1. judgelib - a local-type plugin which provides an online judge function library to any part of Moodle.
  2. judges - judge engine plugins for judgelib.
  3. clients - any kind of moodle plugins can work as the client of judgelib to provide UI to teachers and students and call the judgelib to judge submissions.

Now, this plugin includes two judge engines:

  1. sandbox compiles and executes C/C++ programs locally in a protected environment. Supports Linux 32/64-bit only.
  2. sphere_engine posts all data to which compiles and executes programs remotely. Supports 40+ languaes, such as C/C++, Java, Python, C#, JavaScript, Perl, PHP. Works in both Windows and Linux.
  3. docker posts all data to docker image which compilers, executes, and limiting their behavior. (Under Development)

Now, this plugin includes one client:

  1. Online Judge Assignment Feedback Plugin - online judge version of the official feedback plugin assignment activity.

The workflow is:

  1. Administrators install and config it.
  2. Teachers create Assignment, choose Online Judge as a feedback type, and setup testcases, etc.
  3. Students submit code in Online Judge Assignment Activities.
  4. The judge daemon judges the submissions in background.
  5. Teachers and students get judge results in Online Judge Assignment Activities.


In Linux

  • Moodle 3.4 or above
  • php-cli
  • (optional but recommended) make, gcc and g++. For 64-bit system, libc 32-bit development libraries, e.g. libc6-dev-i386, glibc-devel.i386, are required.
  • (optional but recommended) pcntl and posix extension for php-cli
  • Ensure that SELinux allows apache to execute outgoing HTTP requests through the following command
getsebool httpd_can_network_connect

if it is not set true, run:

setsebool -P httpd_can_network_connect on

In Windows

  • Moodle 3.4 or above
  • php-cli


Using git:

git clone -b OJ_VERSION git:// onlinejudge

OJ_VERSION is obtained from the available branches.

Installation / Upgrading

MOODLE_PATH means the root path of your moodle installation. Do NOT ignore the bold steps during upgrading. In Linux

  1. If the directory MOODLE_PATH/local/onlinejudge exists, remove it.
  2. Make sure the directory name of this plugin is onlinejudge. If not, rename it.
  3. Put onlinejudge into MOODLE_PATH/local/
  4. run MOODLE_PATH/local/onlinejudge/cli/install_assign_feedback.
  5. Login your site as admin and access /admin/index.php. The plugins will be installed/upgraded.
  6. In shell, sudo -u www-data php MOODLE_PATH/local/onlinejudge/cli/judged.php, to launch the judge daemon.
  7. If you would like to use sandbox judge engine, then:
cd MOODLE_PATH/local/onlinejudge/judge/sandbox/sand/ && make

Note: Make sure the file named sand is executable, and has the following context: system_u:object_r:bin_t:s0.

In Windows

  1. If the folder MOODLE_PATH\local\onlinejudge exists, remove it.
  2. Make sure the folder name of this plugin is onlinejudge. If not, rename it.
  3. Put onlinejudge into MOODLE_PATH\local\
  4. Enter folder MOODLE_PATH\local\onlinejudge\cli and run install_assign_feedback.bat.
  5. Login your site as admin and access /admin/index.php. The plugins will be installed/upgraded.
  6. In command prompt, php.exe MOODLE_PATH\local\onlinejudge\cli\judged.php -v, to launch the judge daemon.

Sphere Engine

In order to start using sphere engine, you have go to the following path:


and run:

composer require guzzlehttp/guzzle


Online Judge Assignment Feedback Type

After installation, there will be a new assignment feedback type called Online Judge appears in the "Feedback types" while creating the assignment. Simply check it it and follow the inline help.

After creating the assignment, two buttons will appear in the assignment page context, Test Case Management and Rejudge All buttons.

Judge Daemon

The judge daemon has several helpful options for debugging purposes. Try argument --help.




Bug reports, feature requests, help wanted and other issues: