Generates shell script that merges multiple GIT repositories into subfolders into a new repository

GitMergeReposInSubfolders.cs

/**
 * Generates shell script that merges multiple GIT repositories into subfolders into a new repository
 * This script will output only a shell script which will automatically do all this booring git magic for you
 * This code is not mean to be effective as-a-code in any way
 * This code is under WTFPL Licence: http://www.wtfpl.net/
 * Tested on .Net Core 2.1.0 preview
 *
 * 
 * **EXAMPLE**
 * You have <repos> A, B, C. You want to create a <new repo> X which will contain <repos> in subfolders:
 * /<new repo>
 *    ./A
 *    ./B
 *    ./C
 *
 * 
 * **USAGE**
 * cd /directory/where/you/want/all/things/to/happen
 * wget https://gist.github.com/tonakriz/e2e27cbedaf7ad2b79a6d26591a8f118 -O GitMergeReposInSubfolders.cs
 * nano GitMergeReposInSubfolders.cs
 * # change **SETTINGS** variables according to your own needs and save
 * chmod +x GitMergeReposInSubfolders.cs
 * eval "$( dotnet run GitMergeReposInSubfolders.cs )"
 * # wait... after script finishes, your all-in-one repo is in folder ./<NewRepoName>
 *
 * 
 * **SETTINGS**
 * NewRepoName
 * - name of the new repository
 * Url
 * - url to GIT server with {0} instead of repo name
 * - example: https://github.com/USERNAME/{0}.git
 * RepoNames
 * - list of names of repositories you want to merge
 *
 
 * **COMMANDS**
 * - Templates of shell commands that do all the magic you need
 *
 
 * Not-proud author: Antonin Kriz, https://antoninkriz.eu, https://github.com/tonakriz
 */

using System;
using System.Text;

namespace GitScriptGenerator
{
    internal static class Program
    {
        //** SETTINGS **//
        private const string NewRepoName = "NewRepoName";
        
        private const string Url = "https://github.com/USERNAME/{0}.git";

        private static readonly string[] RepoNames = {
            "A",
            "B",
            "C"
        };

        //** COMMANDS **//
        private const string TeplateInit = "git init {0};";
        private const string TemplateClone = "git clone " + Url + ";";
        private const string TemplateCd = "cd {0};";
        private const string TemplateFilterBranch = "git filter-branch -f --index-filter 'git ls-files -s | awk -v prefix=\"{0}/\" \"{{ sub(/\\t/, \\\"\\t\\\" prefix); print}}\" | GIT_INDEX_FILE=$GIT_INDEX_FILE.new git update-index --index-info && mv \"$GIT_INDEX_FILE.new\" \"$GIT_INDEX_FILE\"' HEAD;";
        private const string TemplateRemoteAddPull = "git remote add {0} ../{0};git pull {0} master;";
        private const string TemplateRmRf = "rm -rf {0};";
    
        //** DO MAGIC STUFF **//
        private static void Main()
        {
            var sb = new StringBuilder();
            
            sb.AppendFormat(TeplateInit, NewRepoName);
            
            foreach (var s in RepoNames)
            {
                sb.AppendFormat(TemplateClone, s);
                sb.AppendFormat(TemplateCd, s);
                sb.AppendFormat(TemplateFilterBranch, s);
                sb.AppendFormat(TemplateCd, "..");
            }

            sb.AppendFormat(TemplateCd, NewRepoName);

            foreach (var s in RepoNames)
            {
                sb.AppendFormat(TemplateRemoteAddPull, s);
            }
            
            sb.AppendFormat(TemplateCd, "..");
            
            foreach (var s in RepoNames)
            {
                sb.AppendFormat(TemplateRmRf, s);
            }
            
            Console.Write(sb.ToString());
        }
    }
}