Embed a Document in a post in SharePoint Server 2013 using .Net csom

Steps

• Open Visual Studio in your system
• Select Console Applciation template and give as name .
• Add a Microsoft.Cleint Assembly refrence file in right side refrence tab in visual studio.
• Replace Program.cs with the source code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.SharePoint.Client;
using Microsoft.SharePoint.Client.Social;

namespace EmbedDocumentInPost
{
    class Program
    {
        static void Main(string[] args)
        {
            // Replace the following placeholder values with the actual values.
            const string serverUrl = "http://gauti.sharepoint.com/sp";
            const string documentUrl = "http://gauti.sharepoint.com//Shared%20Documents/fileName.docx";

            try
            {

                // Get the context and the SocialFeedManager instance.
                ClientContext clientContext = new ClientContext(serverUrl);
                SocialFeedManager feedManager = new SocialFeedManager(clientContext);

                // Get the document attachment from the server.
                ClientResult<SocialAttachment> attachment = feedManager.GetPreview(documentUrl);
                clientContext.ExecuteQuery();

                // Define properties for the post and add the attachment.
                SocialPostCreationData postCreationData = new SocialPostCreationData();
                postCreationData.ContentText = "Post with a document.";
                postCreationData.Attachment = attachment.Value;

                // Publish the post. This is a root post to the user's feed, so specify
                // null for the targetId parameter.
                feedManager.CreatePost(null, postCreationData);
                clientContext.ExecuteQuery();
                Console.Write("The post was published.");
                Console.ReadLine();
            }
            catch (Exception ex)
            {
                Console.Write("Error publishing the post: " + ex.Message);
                Console.ReadLine();
            }
        }
    }
}