Rename figure files in given directory, excluding dot and '/': ./fig/dir/file_param_1.1_param2.2.pdf into ./figdirfile_param1_1_param2_2.pdf For compiling latex project it was necessary to have all the files in one directory and retaining their unique name, at the same time replacing the '.' from file name.

gistfile1.txt

using System;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 1)
            {
                if (File.Exists(args[0]))
                {
                    string parentDir = Directory.GetParent(args[0]).FullName;

                    StringBuilder fileContents = new StringBuilder();
                    
                    using (StreamReader reader = new StreamReader(args[0]))
                    {
                        fileContents.Append(reader.ReadToEnd());
                    }

                    var tt = Regex.Matches(fileContents.ToString(), @"\{./fig/.*\}");
                    string fileContentsOut = fileContents.ToString();

                    int count = 0;

                    foreach (var t in tt)
                    {
                        string figPath = t.ToString().Replace("{", "").Replace("}", "");

                        Regex rgx = new Regex("[^a-zA-Z0-9]");
                        string figPathOut = rgx.Replace(figPath, "");

                        fileContentsOut = fileContentsOut.Replace(figPath, figPathOut);

                        figPath += (figPath.EndsWith(".pdf"))?"":".pdf";
                        figPathOut += (figPathOut.EndsWith(".pdf"))?"":".pdf";

                        var tryiti = figPath.TrimStart('.').Replace('/', Path.DirectorySeparatorChar);
                        string figSource = parentDir + tryiti;// Path.Combine(parentDir, tryiti);
                        string figDest = Path.Combine(parentDir, figPathOut);

                        if (File.Exists(figSource))
                        {
                            File.Copy(figSource, figDest, false);
                            count++;
                        }
                        else
                        {
                            Console.WriteLine("! " + figSource);
                        }

                    }

                    Console.WriteLine(count + " files.");

                    File.WriteAllText(args[0] + ".out", fileContentsOut);

                }
            }
            Console.WriteLine("Press any key to stop...");
            Console.ReadKey();
        }
    }
}