diff --git a/DTLib.Logging/Loggers/FileLogger.cs b/DTLib.Logging/Loggers/FileLogger.cs
index 0736c21..dc8f1d6 100644
--- a/DTLib.Logging/Loggers/FileLogger.cs
+++ b/DTLib.Logging/Loggers/FileLogger.cs
@@ -27,7 +27,7 @@ public class FileLogger : ILogger
     {}
 
     public FileLogger(string dir, string programName, ILogFormat format)
-        : this($"{dir}{Путь.Разд}{programName}_{DateTime.Now.ToString(MyTimeFormat.ForFileNames)}.log", format)
+        : this($"{dir}{Path.Sep}{programName}_{DateTime.Now.ToString(MyTimeFormat.ForFileNames)}.log", format)
     {}
 
     public FileLogger(string dir, string programName) : this(dir, programName, new DefaultLogFormat())
diff --git a/DTLib.Network/FSP.cs b/DTLib.Network/FSP.cs
index d418497..b424b00 100644
--- a/DTLib.Network/FSP.cs
+++ b/DTLib.Network/FSP.cs
@@ -18,8 +18,8 @@ public class FSP
     // скачивает файл с помощью FSP протокола
     public void DownloadFile(string filePath_server, string filePath_client)
     {
-        Путь.Предупредить(filePath_server);
-        Путь.Предупредить(filePath_client);
+        Path.ThrowIfEscapes(filePath_server);
+        Path.ThrowIfEscapes(filePath_client);
         lock (MainSocket)
         {
             Debug("b", $"requesting file download: {filePath_server}");
@@ -31,7 +31,7 @@ public class FSP
 
     public void DownloadFile(string filePath_client)
     {
-        Путь.Предупредить(filePath_client);
+        Path.ThrowIfEscapes(filePath_client);
         using System.IO.Stream fileStream = File.OpenWrite(filePath_client);
         Download_SharedCode(fileStream, true);
         fileStream.Close();
@@ -40,7 +40,7 @@ public class FSP
 
     public byte[] DownloadFileToMemory(string filePath_server)
     {
-        Путь.Предупредить(filePath_server);
+        Path.ThrowIfEscapes(filePath_server);
         lock (MainSocket)
         {
             Debug("b", $"requesting file download: {filePath_server}");
@@ -102,7 +102,7 @@ public class FSP
     // отдаёт файл с помощью FSP протокола
     public void UploadFile(string filePath)
     {
-        Путь.Предупредить(filePath);
+        Path.ThrowIfEscapes(filePath);
         BytesUploaded = 0;
         Debug("b", $"uploading file {filePath}");
         using System.IO.FileStream fileStream = File.OpenRead(filePath);
@@ -137,10 +137,10 @@ public class FSP
 
     public void DownloadByManifest(string dirOnServer, string dirOnClient, bool overwrite = false, bool delete_excess = false)
     {
-        if (!dirOnClient.EndsWith(Путь.Разд))
-            dirOnClient += Путь.Разд;
-        if (!dirOnServer.EndsWith(Путь.Разд))
-            dirOnServer += Путь.Разд;
+        if (!dirOnClient.EndsWith(Path.Sep))
+            dirOnClient += Path.Sep;
+        if (!dirOnServer.EndsWith(Path.Sep))
+            dirOnServer += Path.Sep;
         Debug("b", "downloading manifest <", "c", dirOnServer + "manifest.dtsod", "b", ">");
         var manifest = new DtsodV23(DownloadFileToMemory(dirOnServer + "manifest.dtsod").BytesToString(StringConverter.UTF8));
         Debug("g", $"found {manifest.Values.Count} files in manifest");
@@ -183,8 +183,8 @@ public class FSP
             Log("y", $"can't create manifest, dir <{dir}> doesn't exist");
             return;
         }
-        if (!dir.EndsWith(Путь.Разд))
-            dir += Путь.Разд;
+        if (!dir.EndsWith(Path.Sep))
+            dir += Path.Sep;
         Log($"b", $"creating manifest of {dir}");
         StringBuilder manifestBuilder = new();
         Hasher hasher = new();
diff --git a/DTLib.Tests/Dtsod/TestDtsodV23.cs b/DTLib.Tests/Dtsod/TestDtsodV23.cs
index 5f7ac9a..82c5a33 100644
--- a/DTLib.Tests/Dtsod/TestDtsodV23.cs
+++ b/DTLib.Tests/Dtsod/TestDtsodV23.cs
@@ -17,7 +17,7 @@ public static class TestDtsodV23
     public static void TestBaseTypes()
     {
         OldLogger.Log("c", "-----[TestDtsodV23/TestBaseTypes]-----");
-        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}base_types.dtsod"));
+        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}base_types.dtsod"));
         foreach (var pair in dtsod)
             OldLogger.Log("b", pair.Value.GetType().Name + ' ', "w", pair.Key + ' ', "c", pair.Value.ToString());
         OldLogger.Log("g", "test completed");
@@ -25,7 +25,7 @@ public static class TestDtsodV23
     public static void TestLists()
     {
         OldLogger.Log("c", "-------[TestDtsodV23/TestLists]-------");
-        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}lists.dtsod"));
+        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}lists.dtsod"));
         foreach (var pair in dtsod)
         {
             OldLogger.Log("b",  pair.Value.GetType().Name + ' ', "w", pair.Key, "c",
@@ -39,7 +39,7 @@ public static class TestDtsodV23
     public static void TestComplexes()
     {
         OldLogger.Log("c", "-----[TestDtsodV23/TestComplexes]-----");
-        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}complexes.dtsod"));
+        DtsodV23 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}complexes.dtsod"));
         foreach (var complex in dtsod)
         {
             OldLogger.Log("b", complex.Value.GetType().Name + ' ', "w", complex.Key,
@@ -55,7 +55,7 @@ public static class TestDtsodV23
     {
         OldLogger.Log("c", "--[TestDtsodV23/TestReSerialization]--");
         var dtsod = new DtsodV23(new DtsodV23(new DtsodV23(
-            new DtsodV23(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}complexes.dtsod")).ToString()).ToString()).ToString());
+            new DtsodV23(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}complexes.dtsod")).ToString()).ToString()).ToString());
         OldLogger.Log("y", dtsod.ToString());
         OldLogger.Log("g", "test completed");
     }
@@ -64,7 +64,7 @@ public static class TestDtsodV23
     {
         OldLogger.Log("c", "-------[TestDtsodV23/TestSpeed]-------");
         IDtsod dtsod=null;
-        string text = File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}messages.dtsod");
+        string text = File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}messages.dtsod");
         LogOperationTime("V21 deserialization",64,()=>dtsod=new DtsodV21(text));
         LogOperationTime("V21 serialization", 64, () => _=dtsod.ToString());
         LogOperationTime("V23 deserialization", 64, () => dtsod = new DtsodV23(text));
@@ -75,7 +75,7 @@ public static class TestDtsodV23
     public static void TestMemoryConsumption()
     {
         OldLogger.Log("c", "----[TestDtsodV23/TestMemConsumpt]----");
-        string text = File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}messages.dtsod");
+        string text = File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}messages.dtsod");
         var a = GC.GetTotalMemory(true);
         var dtsods = new DtsodV23[64];
         for (int i = 0; i < dtsods.Length; i++)
diff --git a/DTLib.Tests/Dtsod/TestDtsodV24.cs b/DTLib.Tests/Dtsod/TestDtsodV24.cs
index 5e840bb..3861c36 100644
--- a/DTLib.Tests/Dtsod/TestDtsodV24.cs
+++ b/DTLib.Tests/Dtsod/TestDtsodV24.cs
@@ -18,7 +18,7 @@ public static class TestDtsodV24
     public static void TestBaseTypes()
     {
         OldLogger.Log("c", "-----[TestDtsodV24/TestBaseTypes]-----");
-        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV24{Путь.Разд}base_types.dtsod"));
+        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV24{Path.Sep}base_types.dtsod"));
         foreach (var pair in dtsod)
             OldLogger.Log("b", pair.ToString());
         OldLogger.Log("g", "test completed");
@@ -27,7 +27,7 @@ public static class TestDtsodV24
     public static void TestComplexes()
     {
         OldLogger.Log("c", "-----[TestDtsodV24/TestComplexes]-----");
-        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV24{Путь.Разд}complexes.dtsod"));
+        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV24{Path.Sep}complexes.dtsod"));
         OldLogger.Log("h", dtsod.ToString());
         OldLogger.Log("g", "test completed");
     }
@@ -35,7 +35,7 @@ public static class TestDtsodV24
     public static void TestLists()
     {
         OldLogger.Log("c", "-------[TestDtsodV24/TestLists]-------");
-        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV24{Путь.Разд}lists.dtsod"));
+        DtsodV24 dtsod = new(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV24{Path.Sep}lists.dtsod"));
         foreach (KVPair pair in dtsod)
         {
             var list = new Autoarr<Unitype>(pair.value.VoidPtr, false);
@@ -60,7 +60,7 @@ public static class TestDtsodV24
     {
         OldLogger.Log("c", "--[TestDtsodV24/TestReSerialization]--");
         var dtsod = new DtsodV24(new DtsodV24(new DtsodV24(
-            new DtsodV24(File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV24{Путь.Разд}complexes.dtsod")).ToString()).ToString()).ToString());
+            new DtsodV24(File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV24{Path.Sep}complexes.dtsod")).ToString()).ToString()).ToString());
         OldLogger.Log("h", dtsod.ToString());
         OldLogger.Log("g", "test completed");
     }
@@ -69,12 +69,12 @@ public static class TestDtsodV24
     {
         OldLogger.Log("c", "-------[TestDtsodV24/TestSpeed]-------");
         IDtsod dtsod=null;
-        string _text = File.ReadAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV23{Путь.Разд}messages.dtsod");
+        string _text = File.ReadAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV23{Path.Sep}messages.dtsod");
         string text = "";
         LogOperationTime( "V23 to V24 conversion", 32, ()=>
             text = DtsodConverter.ConvertVersion(new DtsodV23(_text), DtsodVersion.V24).ToString()
         );
-        File.WriteAllText($"Dtsod{Путь.Разд}TestResources{Путь.Разд}DtsodV24{Путь.Разд}messages.dtsod",text);
+        File.WriteAllText($"Dtsod{Path.Sep}TestResources{Path.Sep}DtsodV24{Path.Sep}messages.dtsod",text);
         LogOperationTime("V24 deserialization", 64, () => dtsod = new DtsodV24(text));
         LogOperationTime("V24 serialization", 64, () => text = dtsod.ToString());
         OldLogger.Log("g", "test completed");
diff --git a/DTLib/DependencyResolver.cs b/DTLib/DependencyResolver.cs
index fc43bb2..b9f5f63 100644
--- a/DTLib/DependencyResolver.cs
+++ b/DTLib/DependencyResolver.cs
@@ -9,14 +9,14 @@ public static class DependencyResolver
     public static void CopyLibs()
     {
         if(DepsCopied) return;
-        string depsdir = $"Dependencies{Путь.Разд}";
+        string depsdir = $"Dependencies{Path.Sep}";
         depsdir += Environment.OSVersion.Platform switch
         {
             PlatformID.Unix => "linux",
             PlatformID.Win32NT => "windows",
             _=> throw new Exception($"unsupported os {Environment.OSVersion.Platform}")
         };
-        depsdir += Путь.Разд;
+        depsdir += Path.Sep;
         depsdir += RuntimeInformation.ProcessArchitecture switch
         {
             Architecture.X64 => "x64",
@@ -27,7 +27,7 @@ public static class DependencyResolver
         };
         foreach (var file in Directory.GetAllFiles(depsdir))
         {
-            var extracted = file.Substring(file.LastIndexOf(Путь.Разд) + 1);
+            var extracted = file.Substring(file.LastIndexOf(Path.Sep) + 1);
             File.Copy(file,extracted, true);
             Log("g",$"{extracted} copied");
         }
diff --git a/DTLib/Experimental/FileInstance.cs b/DTLib/Experimental/FileInstance.cs
new file mode 100644
index 0000000..a457fbd
--- /dev/null
+++ b/DTLib/Experimental/FileInstance.cs
@@ -0,0 +1,45 @@
+using System.IO;
+
+namespace DTLib.Experimental;
+
+public class FileInstance
+{
+    public enum FileOpenMode
+    {
+        // open a file for reading 
+        Read=1, 
+        // (re)create a file for writing
+        Write=2, 
+        // opens file for writing additional data to the end / creates new file 
+        Append=4,
+        // (re)creates file for reading/writing
+        ReadWrite=Read|Write, 
+        // opens file for readng/writing additional data to the end / creates new file 
+        ReadAppend=Read|Append
+    }
+
+    public readonly FileOpenMode Mode;
+    public readonly FileStream Stream;
+    public string Name;
+    
+    public FileInstance(string path, FileOpenMode mode)
+    {
+        if (path.IsNullOrEmpty())
+            throw new NullReferenceException("path is null");
+        if(!System.IO.File.Exists(path))
+        {
+            if (mode == FileOpenMode.Read)
+                throw new Exception($"file <{path}> is not found");
+        }
+        Mode = mode;
+        Stream = mode switch
+        {
+            FileOpenMode.Read => System.IO.File.Open(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite),
+            FileOpenMode.Write => System.IO.File.Open(path, FileMode.Open, FileAccess.Write, FileShare.ReadWrite),
+            FileOpenMode.Append => System.IO.File.Open(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite),
+            FileOpenMode.ReadWrite => System.IO.File.Open(path, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite),
+            FileOpenMode.ReadAppend => System.IO.File.Open(path, FileMode.Append, FileAccess.ReadWrite, FileShare.ReadWrite),
+            _ => throw new Exception($"unknown file mode: {mode}")
+        };
+    }
+}
\ No newline at end of file
diff --git a/DTLib/Extensions/StringConverter.cs b/DTLib/Extensions/StringConverter.cs
index 6dc3032..40f5db0 100644
--- a/DTLib/Extensions/StringConverter.cs
+++ b/DTLib/Extensions/StringConverter.cs
@@ -43,35 +43,51 @@ public static class StringConverter
     public static bool StartsWith(this string s, char c) => s[0] == c;
     public static bool EndsWith(this string s, char c) => s[s.Length - 1] == c;
 
-    public static string MergeToString(params object[] parts)
+    // String.Join(sep,string...) does some low-level memory manipulations, that are faster than StringBuilder
+    public static string MergeToString(params string[] parts)
+        =>string.Join(null, parts);
+    
+    public static string MergeToString<TVal>(params TVal[] parts)
     {
+        if (parts.Length == 0)
+            return "";
         StringBuilder builder = new();
         for (int i = 0; i < parts.Length; i++)
             builder.Append(parts[i]);
         return builder.ToString();
     }
-    
-    // String.Join(sep,string...) does some low-level memory manipulations, that are faster than StringBuilder
-    public static string MergeToString(params string[] parts)
-        =>string.Join(null, parts);
-    
-    public static string MergeToString<T>(this IEnumerable<T> collection, string separator)
+    public static string MergeToString<TVal, TSep>(TSep separator, params TVal[] parts)
     {
-        StringBuilder builder = new();
-        foreach (T elem in collection)
-        {
-            builder.Append(elem);
-            builder.Append(separator);
-        }
-        if (builder.Length == 0)
+        if (parts.Length == 0)
             return "";
-        builder.Remove(builder.Length - separator.Length, separator.Length);
+        StringBuilder builder = new();
+        builder.Append(parts[0]);
+        for (int i = 1; i < parts.Length; i++)
+        {
+            builder.Append(separator);
+            builder.Append(parts[i]);
+        }
         return builder.ToString();
     }
-    public static string MergeToString<T>(this IEnumerable<T> collection)
+    
+    public static string MergeToString<TVal, TSep>(this IEnumerable<TVal> collection, TSep separator)
     {
         StringBuilder builder = new();
-        foreach (T elem in collection)
+        using var e = collection.GetEnumerator();
+        if(e.MoveNext()) 
+            builder.Append(e.Current);
+        while (e.MoveNext())
+        {
+            builder.Append(separator);
+            builder.Append(e.Current);
+        }
+        return builder.ToString();
+    }
+    
+    public static string MergeToString<TVal>(this IEnumerable<TVal> collection)
+    {
+        StringBuilder builder = new();
+        foreach (var elem in collection)
             builder.Append(elem);
         return builder.ToString();
     }
diff --git a/DTLib/Filesystem/Directory.cs b/DTLib/Filesystem/Directory.cs
index 8ed3de6..bf7158a 100644
--- a/DTLib/Filesystem/Directory.cs
+++ b/DTLib/Filesystem/Directory.cs
@@ -10,8 +10,8 @@ public static class Directory
         if (!Exists(dir))
         {
             // проверяет существование папки, в которой нужно создать dir
-            if (dir.Contains(Путь.Разд) && !Exists(dir.Remove(dir.LastIndexOf(Путь.Разд))))
-                Create(dir.Remove(dir.LastIndexOf(Путь.Разд)));
+            if (dir.Contains(Path.Sep) && !Exists(dir.Remove(dir.LastIndexOf(Path.Sep))))
+                Create(dir.Remove(dir.LastIndexOf(Path.Sep)));
             System.IO.Directory.CreateDirectory(dir);
         }
     }
@@ -100,8 +100,8 @@ public static class Directory
 
     public static void CreateSymlink(string sourceName, string symlinkName)
     {
-        if (symlinkName.Contains(Путь.Разд))
-            Create(symlinkName.Remove(symlinkName.LastIndexOf(Путь.Разд)));
+        if (symlinkName.Contains(Path.Sep))
+            Create(symlinkName.Remove(symlinkName.LastIndexOf(Path.Sep)));
         if (!Symlink.CreateSymbolicLink(symlinkName, sourceName, Symlink.SymlinkTarget.Directory))
             throw new InvalidOperationException($"some error occured while creating symlink\nDirectory.CreateSymlink({symlinkName}, {sourceName})");
     }
@@ -110,8 +110,8 @@ public static class Directory
     public static int SymCopy(string srcdir, string newdir)
     {
         List<string> files = GetAllFiles(srcdir);
-        if (!srcdir.EndsWith(Путь.Разд)) srcdir += Путь.Разд;
-        if (!newdir.EndsWith(Путь.Разд)) newdir += Путь.Разд;
+        if (!srcdir.EndsWith(Path.Sep)) srcdir += Path.Sep;
+        if (!newdir.EndsWith(Path.Sep)) newdir += Path.Sep;
         int i = 0;
         for (; i < files.Count; i++)
             File.CreateSymlink(files[i], files[i].Replace(srcdir, newdir));
diff --git a/DTLib/Filesystem/File.cs b/DTLib/Filesystem/File.cs
index 756b5da..1be3f16 100644
--- a/DTLib/Filesystem/File.cs
+++ b/DTLib/Filesystem/File.cs
@@ -3,7 +3,7 @@ namespace DTLib.Filesystem;
 
 public static class File
 {
-    public static int GetSize(string file) => new System.IO.FileInfo(file).Length.ToInt();
+    public static long GetSize(string file) => new System.IO.FileInfo(file).Length;
 
     public static bool Exists(string file) => System.IO.File.Exists(file);
 
@@ -12,8 +12,8 @@ public static class File
     {
         if (!Exists(file))
         {
-            if (file.Contains(Путь.Разд))
-                Directory.Create(file.Remove(file.LastIndexOf(Путь.Разд)));
+            if (file.Contains(Path.Sep))
+                Directory.Create(file.Remove(file.LastIndexOf(Path.Sep)));
             using System.IO.FileStream stream = System.IO.File.Create(file);
             stream.Close();
         }
@@ -32,9 +32,10 @@ public static class File
     public static byte[] ReadAllBytes(string file)
     {
         using System.IO.FileStream stream = OpenRead(file);
-        int size = GetSize(file);
+        int size = GetSize(file).ToInt();
         byte[] output = new byte[size];
-        stream.Read(output, 0, size);
+        if (stream.Read(output, 0, size) < size)
+            throw new Exception("can't read all bytes");
         stream.Close();
         return output;
     }
@@ -78,8 +79,8 @@ public static class File
 
     public static void CreateSymlink(string sourceName, string symlinkName)
     {
-        if (symlinkName.Contains(Путь.Разд))
-            Directory.Create(symlinkName.Remove(symlinkName.LastIndexOf(Путь.Разд)));
+        if (symlinkName.Contains(Path.Sep))
+            Directory.Create(symlinkName.Remove(symlinkName.LastIndexOf(Path.Sep)));
         if (!Symlink.CreateSymbolicLink(symlinkName, sourceName, Symlink.SymlinkTarget.File))
             throw new InvalidOperationException($"some error occured while creating symlink\nFile.CreateSymlink({symlinkName}, {sourceName})");
     }
diff --git a/DTLib/Filesystem/Path.cs b/DTLib/Filesystem/Path.cs
new file mode 100644
index 0000000..864fd4e
--- /dev/null
+++ b/DTLib/Filesystem/Path.cs
@@ -0,0 +1,74 @@
+using System.Runtime.CompilerServices;
+
+namespace DTLib.Filesystem;
+
+public static class Path
+{
+    
+    public static readonly char Sep = Environment.OSVersion.Platform == PlatformID.Win32NT ? '\\' : '/';
+    private static readonly char NotSep = Environment.OSVersion.Platform == PlatformID.Win32NT ? '/' : '\\' ;
+    
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string Concat(string path, string addition) => $"{path}{Sep}{addition}";
+    
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string Concat(params string[] parts) => StringConverter.MergeToString(Sep, parts);
+
+    public static string FixSeparators(string path)
+    {
+        var chars = path.ToCharArray();
+        int length = path.Length;
+        for(int i=0; i<length; i++)
+            if (chars[i] == NotSep)
+                chars[i] = Sep;
+        return chars.ToString();
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string Resolve(params string[] parts) => FixSeparators(Concat(parts));
+    
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static string Resolve(string path, string addition) => FixSeparators(Concat(path, addition));
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static void ThrowIfEscapes(string path)
+    {
+        if (path.Contains(".."))
+            throw new Exception($"path <{path}> uses <..>, that's not allowed");
+    }
+
+    /// Replaces restricted characters in string
+    public static string CorrectString(string str)
+    {
+#if  NETSTANDARD2_1 || NET6_0 || NET7_0 || NET8_0
+        var a = str.AsSpan();
+#else
+        var a = str.ToArray();
+#endif
+        char[] r = new char[a.Length];
+        for (int i = 0; i < a.Length; i++)
+        {
+            switch (a[i])
+            {
+                case '/': case '\\':
+                case ':': case ';':
+                    r[i] = '-';
+                    break;
+                case '\n': case '\r': case ' ':
+                case '#': case '%': case '&':
+                case '{': case '}': case '<':
+                case '>': case '*': case '?':
+                case '$': case '!': case '\'':
+                case '"': case '@': case '+':
+                case '`': case '|': case '=':
+                    r[i] = '_';
+                    break;
+                default:
+                    r[i] = a[i];
+                    break;
+            }
+        }
+
+        return new string(r);
+    }
+}
\ No newline at end of file
diff --git a/DTLib/Filesystem/Путь.cs b/DTLib/Filesystem/Путь.cs
deleted file mode 100644
index 7e8baf1..0000000
--- a/DTLib/Filesystem/Путь.cs
+++ /dev/null
@@ -1,31 +0,0 @@
-namespace DTLib.Filesystem;
-
-public static class Путь
-{
-    public static readonly char Разд = Environment.OSVersion.Platform == PlatformID.Win32NT ? '\\' : '/';
-
-    public static string ИсправитьРазд(this string путь)
-    {
-        if (Разд == '\\')
-        {
-            if (путь.Contains('/'))
-                путь = путь.Replace('/', '\\');
-        }
-        else
-        {
-            if (путь.Contains('\\'))
-                путь = путь.Replace('\\', '/');
-        }
-        return путь;
-    }
-
-    // replaces wrong characters to use string as путь
-    public static string НормализоватьДляПути(this string путь) =>
-        путь.Replace(':', '-').Replace(' ', '_');
-
-    public static void Предупредить(string может_быть_с_точками)
-    {
-        if(может_быть_с_точками.Contains("..")) 
-            throw new Exception($"лее точки двойные убери: {может_быть_с_точками}");
-    }
-}
\ No newline at end of file
diff --git a/DTLib/Logging/FileLogger.cs b/DTLib/Logging/FileLogger.cs
index eb674aa..b0c5ade 100644
--- a/DTLib/Logging/FileLogger.cs
+++ b/DTLib/Logging/FileLogger.cs
@@ -9,7 +9,7 @@ public class FileLogger : IDisposable
     }
 
     public FileLogger(string dir, string programName)
-        : this($"{dir}{Путь.Разд}{programName}_{DateTime.Now.ToString(MyTimeFormat.ForFileNames)}.log") { }
+        : this($"{dir}{Path.Sep}{programName}_{DateTime.Now.ToString(MyTimeFormat.ForFileNames)}.log") { }
     
     public string LogfileName { get; protected set; }
     public System.IO.FileStream LogfileStream { get; protected set; }