Plink returning unwanted characters via C#

Question

I am getting unwanted characters before and after my results when using Plink via C#:

Command:

ls -l */informatica/tgtdynamicparams*.out | grep vaulttest| grep 'Sep  1'|awk '{print $9}' | sort

Linux result:

aaco/informatica/tgtdynamicparams2269885_CHECK_REF_COMPANY.out
cdph/informatica/tgtdynamicparams2225704_CDPHDRUGRECON.out
cdph/informatica/tgtdynamicparams2225704_CDPHELIGRECON.out
merh/informatica/tgtdynamicparams3454321_OPEN_TEST.out
merh/informatica/tgtdynamicparams3454322_OPEN_TEST2.out

C# via Plink result:

[01;32mcdph/informatica/tgtdynamicparams2225704_CDPHDRUGRECON.out[0m
[01;32mcdph/informatica/tgtdynamicparams2225704_CDPHELIGRECON.out[0m
[01;32mmerh/informatica/tgtdynamicparams3454321_OPEN_TEST.out[0m
[01;32mmerh/informatica/tgtdynamicparams3454322_OPEN_TEST2.out[0m
[0m[01;32maaco/informatica/tgtdynamicparams2269885_CHECK_REF_COMPANY.out[0m

I've tried the following without any luck:

StandardOutputEncoding = Encoding.UTF8
StandardOutputEncoding = Encoding.ASCII
StandardOutputEncoding = Encoding.DEFAULT

Here is the code I'm using. I have seen replies for similar problems suggesting use of ssh.net but I am not permitted to use that it has to be Plink.

private string GetFileNames = @"ls -l */informatica/tgtdynamicparams*.out 
                             | grep vaulttest| grep 'Sep  1'
                             | awk '{print $9}' 
                             | sort";

GetProcessesCommands = new [] {
                               @"cd /src/trs/runjobs",
                               GetFileNames
                              };
Request(ServerName, UserName, Password, GetProcessesCommands);

Calls this:

private void Request(string remoteHost, string userName, string password, IEnumerable<string> lstCommands)
{
    try
    {
        var psi = new ProcessStartInfo
        {
            FileName = FormInformatiKill.PropFile.Plink,
            Arguments = string.Format("-ssh {0}@{1} -pw {2}", userName, remoteHost, password),
            RedirectStandardError = true,
            RedirectStandardOutput = true,
            RedirectStandardInput = true,
            UseShellExecute = false,
            CreateNoWindow = true,
            StandardOutputEncoding = Encoding.UTF8
        };

        var p = Process.Start(psi);
        _mObjLock = new object();
        _mBlnDoRead = true;

        if( p == null ) return;
        AsyncReadFeedback(p.StandardOutput); // start the async read of stdout

        var strw = p.StandardInput;

        foreach( var cmd in lstCommands )
        {
            strw.WriteLine( cmd ); // send commands 
        }
        strw.WriteLine("exit"); // send exit command at the end

        p.WaitForExit(); // block thread until remote operations are done  
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
        Console.WriteLine(e.StackTrace);
    }
}

private void AsyncReadFeedback(StreamReader strr)
{
    var trdr = new Thread(ReadFeedback);
    trdr.Start(strr);
}

private void ReadFeedback(object objStreamReader)
{
    var strr = (StreamReader) objStreamReader;
    while (!strr.EndOfStream && _mBlnDoRead)
    {
        var line = strr.ReadLine();
        // lock the feedback buffer (since we don't want some messy stdout/err mix string in the end)
        lock (_mObjLock)
        {
            if( line != null ) ListOfFilesResults.Add(line.Trim());
        }
    }
}

I've tried Trim(). I even spent time just trying to remove the characters I didn't want, but there seems to be more possibilities than I can code for.

Answer 1

Those are ANSI escape codes.

While using the --color=never may help, the root problem is that, the way you run Plink (feeding the command using a standard input), you make it use an interactive session. Most systems nowadays are configured to use a fancy formatting for directory listing (and other stuff) for interactive sessions to be more human friendly.

While in your case, no human is involved, so you should use a non-interactive session.

There are two ways to do that:

• Either provide the command on Plink command-line (instead of feeding it using a standard input), like:

  plink.exe -ssh username@example.com -pw password "ls -l ... | grep ... | sort"
  

  This syntax implicitly forces a non-interactive mode.

• Or use the -T switch to explicitly force the non-interactive mode:

  plink.exe -ssh username@example.com -pw password -T
  

  This syntax allows you to keep feeding the command using the standard input.

Using the non-interactive session (on a properly configured system) you avoid all the troubles of the interactive sessions (not just the --color). So it's a way more generic solution.

---

If this does not work for you, it must be because your server is misconfigured and aliases the ls to use the --color even for non-interactive sessions.

If you cannot fix the server, I suggest you use both non-interactive session (to avoid other possible troubles) and the --color=never switch. Possibly better solution than using the --color=never is using the unalias ls.

Answer 2

Thank You user2864740 ! I added --color=never and those damn characters disappeared.

            private const string GetFileNames = "ls --color=never -l */informatica/tgtdynamicparams*.out  " +
                                        "| grep vaulttest " +
                                        "| grep 'Sep  1' " +
                                        "| awk '{print $9}' " +
                                        "| sort";