C

How to Use iOS GameCenter Leaderboards in Unity3d

You need to setup your app on the appstore connect first with the appropriate leaderboard. And you can only test this code on the iOS device and not in the unity3d player.


using UnityEngine.SocialPlatforms;

  private ILeaderboard leaderboard;
  private string leaderboard_id = "yourleaderboardid"; // setup on appstore connect

 void Start()
 {

    // Authenticate user first
        Social.localUser.Authenticate(success => {
            if (success)
            {
                Debug.Log("Authentication successful");
                string userInfo = "Username: " + Social.localUser.userName +
                    "\nUser ID: " + Social.localUser.id +
                    "\nIsUnderage: " + Social.localUser.underage;
                Debug.Log(userInfo);
            }
            else
                Debug.Log("Authentication failed");
        });

  // create social leaderboard
        leaderboard  = Social.CreateLeaderboard();
        leaderboard.id = leaderboard_id;
        leaderboard.LoadScores(result =>
        {
            Debug.Log("Received " + leaderboard.scores.Length + " scores");
            foreach (IScore score in leaderboard.scores)
                Debug.Log(score);
        });
  }

  void ReportScore(long score, string leaderboardID)
  {
        Debug.Log("Reporting score " + score + " on leaderboard " + leaderboardID);
        Social.ReportScore(score, leaderboardID, success => {
            Debug.Log(success ? "Reported score successfully" : "Failed to report score");
        });
  }

 void OpenLeaderboard()
 {
        Social.ShowLeaderboardUI();
 }

How to fork and pipe multiple processes on Linux

The C code here is used for reference of how to pipe 3 separate children processes. It can be improved to support a dynamic amount of processes and corresponding pipes and system calls.

// This program is an example of how to run a command such as
// ps aux | grep root | grep sbin
// using C and Unix.
// pipe_example.c

#include 
#include 
#include 

int pid;
int pipe1[2];
int pipe2[2];

void exec1();
void exec2();
void exec3();

int main()
{

	// create pipe1
	if (pipe(pipe1) == -1)
	{
		perror("bad pipe1");
		exit(1);
	}

	// create pipe2
	if (pipe(pipe2) == -1)
	{
		perror("bad pipe2");
		exit(1);
	}

	// fork (ps aux)
	if ((pid = fork()) == -1)
	{
		perror("bad fork1");
		exit(1);
	}
	else if (pid == 0)
	{
		// stdin --> ps --> pipe1
		exec1();
	}
	// parent

	// fork (grep root)
	if ((pid = fork()) == -1)
	{
		perror("bad fork2");
		exit(1);
	}
	else if (pid == 0)
	{
		// pipe1 --> grep --> pipe2
		exec2();
	}
	// parent

	// close unused fds
	close(pipe1[0]);
	close(pipe1[1]);

	// fork (grep sbin)
	if ((pid = fork()) == -1)
	{
		perror("bad fork3");
		exit(1);
	}
	else if (pid == 0)
	{
		// pipe2 --> grep --> stdout
		exec3();
	}
	// parent
}

void exec1()
{
	// input from stdin (already done)
	// output to pipe1
	dup2(pipe1[1], 1);
	// close fds
	close(pipe1[0]);
	close(pipe1[1]);
	// exec
	execlp("ls", "ls", NULL);
	// exec didn't work, exit
	perror("bad exec ls");
	_exit(1);
}

void exec2()
{
	// input from pipe1
	dup2(pipe1[0], 0);
	// output to pipe2
	dup2(pipe2[1], 1);
	// close fds
	close(pipe1[0]);
	close(pipe1[1]);
	close(pipe2[0]);
	close(pipe2[1]);
	// exec
	execlp("grep", "grep", "c", NULL);
	// exec didn't work, exit
	perror("bad exec grep c");
	_exit(1);
}

void exec3()
{
	// input from pipe2
	dup2(pipe2[0], 0);
	// output to stdout (already done)
	// close fds
	close(pipe2[0]);
	close(pipe2[1]);
	// exec
	execlp("grep", "grep", "y", NULL);
	// exec didn't work, exit
	perror("bad exec grep y");
	_exit(1);
}

This code also works on Unix/Mac.
Compile with gcc pipe_example.c -o pipe_example.o
Run with ./pipe_example.o