Install and connect to Telnet [Console Application] - c#

Since i finished my School-Project and there is nothing left for now, I started to implement a Easteregg in my little Console Application. It should install telnet (pkgmgr /iu:"TelnetClient") and call the StarWars animation: "telnet" + "o" + "towel.blinkenlights.nl"
To do that, my Application opens up a CMD-Prompt, which installs Telnet:
public static void EastereggInstall()
{
Process cmd = new Process();
cmd.StartInfo.FileName = "cmd.exe";
cmd.StartInfo.RedirectStandardInput = true;
cmd.StartInfo.RedirectStandardOutput = true;
cmd.StartInfo.CreateNoWindow = true;
cmd.StartInfo.UseShellExecute = false;
cmd.Start();
cmd.StandardInput.WriteLine("pkgmgr /iu:'TelnetClient'");
cmd.StandardInput.Flush();
cmd.StandardInput.Close();
Console.WriteLine(cmd.StandardOutput.ReadToEnd());
Environment.Exit(0);
}
After the Task is finished with Environment.Exit(0); it calls another CMD-prompt to connect to the telnet Server which starts the Animation:
public static void EastereggPlay()
{
Process cmd = new Process();
cmd.StartInfo.FileName = "cmd.exe";
cmd.StartInfo.RedirectStandardInput = true;
cmd.StartInfo.RedirectStandardOutput = true;
cmd.StartInfo.CreateNoWindow = true;
cmd.StartInfo.UseShellExecute = false;
cmd.Start();
cmd.StandardInput.WriteLine("telnet" + "o" + "towel.blinkenlights.nl");
cmd.StandardInput.Flush();
cmd.StandardInput.Close();
Console.WriteLine(cmd.StandardOutput.ReadToEnd());
}
However, the first Commandprompt closes itself with no Error-message whatsoever.
I've also tried to use Console.ReadKey() to get the Error, but still no useful info there. My first thought was that cmd.StandardInput.WriteLine("telnet" + "o" + "towel.blinkenlights.nl"); can't be executed by using it in a single line, so i tried
cmd.StandardInput.WriteLine("telnet");
cmd.StandardInput.WriteLine("o");
cmd.StandardInput.WriteLine("towel.blinkenlights.nl");
Still no success. So do you guys know what i should do to get this piece of Code to work? Thanks!

use
ProcessStartInfo startInfo = new ProcessStartInfo("cmd");
startInfo.WindowStyle = ProcessWindowStyle.Normal;
startInfo.Arguments = "/c telnet o towel.blinkenlights.nl";
Process.Start(startInfo);
make sure that command works because the cmd process will just exit if not.
to make sure everything works, try something like
startInfo.Arguments = "/c ping google.com -t";
also, while testing you should consider setting CreateNoWindow to false

Environment.Exit(0) close the whole environment.
You should close only process, so the code can reach the telnet connection.

Related

Command hanging in C# when running Postman's Newman command

I'm trying to use cmd CLI to excute a newman collection run. However when the process is running it's getting stuck and never finishes processing.
Any suggestions on how to deal with that?
string cmdCommand="newman run demo.postman_collection.json --env-var HTTP_PROXY --insecure";
int TotalTimeout= 150000;
CliProcess = new System.Diagnostics.Process();
System.Diagnostics.ProcessStartInfo startInfo = new
System.Diagnostics.ProcessStartInfo();
if (_inputDir != null)
{
startInfo.WorkingDirectory = _inputDir;
}
//startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
startInfo.CreateNoWindow = false;
startInfo.FileName = "cmd.exe";
startInfo.Arguments = "/C "+cmdCommand;
startInfo.UseShellExecute = false;
startInfo.RedirectStandardError = true;
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bool processExited;
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//CliProcess.BeginErrorReadLine();
//CliProcess.Close();
processExited = CliProcess.WaitForExit(TotalTimeout);
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This is the most I can get out of it:
It gets stuck here^ and never continues.
the problem was due to the fact that the proxy was misconfigured so the request was sent trying to get to an unresponsive proxy server...
So in conclusion, there was nothing wrong with the code itself.

"StandardOut has not been redirected or the process hasn't started yet" when reading console command output in C#

Thanks to #user2526830 for the code. Based on that code I added few lines to my program since I want to read the output of the SSH command. Below is my code which gives an error at line while
StandardOut has not been redirected or the process hasn't started yet.
What I want to achieve is that I want to read the output of ls into a string.
ProcessStartInfo startinfo = new ProcessStartInfo();
startinfo.FileName = #"f:\plink.exe";
startinfo.Arguments = "-ssh abc#x.x.x.x -pw abc123";
Process process = new Process();
process.StartInfo = startinfo;
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardInput = true;
process.Start();
process.StandardInput.WriteLine("ls -ltr /opt/*.tmp");
process.StandardInput.WriteLine("exit");
process.StartInfo.RedirectStandardOutput = true;
while (!process.StandardOutput.EndOfStream)
{
string line = process.StandardOutput.ReadLine();
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process.WaitForExit();
Console.ReadKey();
Try setting standard output redirection before starting the process.
process.StartInfo.RedirectStandardOutput = true;
process.Start();
It might be that the process already terminated when you try to read the output (dues to your "exit" command). Try the below slightly modified version where I moved your while loop after the "ls" command but before the "exit" command.
It should read the output of your "ls" command fine, but unfortunately will most probably hang at some point as you will never get EndOfStream on the StandardOutput. When there is nothing more to read, ReadLine will block until it can get read another line.
So unless you know how to detect the last line of the output generated by your command and break out of the loop after you read it, you may need to use a separate thread either for reading or for writing.
ProcessStartInfo startinfo = new ProcessStartInfo();
startinfo.FileName = #"f:\plink.exe";
startinfo.Arguments = "-ssh abc#x.x.x.x -pw abc123";
Process process = new Process();
process.StartInfo = startinfo;
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardInput = true;
process.StartInfo.RedirectStandardOutput = true;
process.Start();
process.StandardInput.WriteLine("ls -ltr /opt/*.tmp");
while (!process.StandardOutput.EndOfStream)
{
string line = process.StandardOutput.ReadLine();
}
process.StandardInput.WriteLine("exit");
process.WaitForExit();
Console.ReadKey();

C# Start Process on Mac - FFMPEG - Exit Code 1

I am trying to start a process on Mac and Windows (using Unity) to run FFMPEG to convert a video to a .ogv video. My code is as follows:
string command = "ffmpeg -i '" + filepath + "' -codec:v libtheora -qscale:v 10 -codec:a libvorbis -qscale:a 10 -y '"+workingDir+"/ogv_Video/"+System.IO.Path.GetFileNameWithoutExtension(filepath)+".ogv'";
UnityEngine.Debug.Log("Command: "+command);
try{
System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo (workingDir+"/..", command);
startInfo.CreateNoWindow = true;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
startInfo.UseShellExecute = false;
startInfo.FileName =workingDir+"/ffmpeg";
//Process.Start (startInfo);
Process p = Process.Start(startInfo);
p.EnableRaisingEvents = true;
string strOutput = p.StandardOutput.ReadToEnd();
UnityEngine.Debug.Log ("Running..."+strOutput);
p.WaitForExit();
UnityEngine.Debug.Log ("Got here. "+strOutput);
int exitCode = p.ExitCode;
UnityEngine.Debug.Log ("Process exit code = "+exitCode);
}
catch(Exception e) {
UnityEngine.Debug.Log ("An error occurred");
UnityEngine.Debug.Log ("Error: "+e);
}
The command executes and does not through any exception. However, it terminates instantly and prints Exit Code 1 which is "Catchall for general errors" -this seems not too helpful!
What am I doing wrong with my code, please?
You'll notice that my code prints out the command in full. If I copy that command and paste it into the terminal, it runs absolutely fine.
It turns out I was setting up the arguments wrongly. Referring to this Stack Overflow question, I was able to produce the expected result with the following code:
try{
Process process = new Process();
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.FileName = Path.GetDirectoryName(System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName) +#"ffmpeg";
process.StartInfo.Arguments = command;
process.StartInfo.UseShellExecute = false;
process.StartInfo.CreateNoWindow = true;
process.Start();
JSONDataObject rtnMsg = new JSONDataObject("StartConvertOK", "-1", new List<string>());
return JsonUtility.ToJson(rtnMsg);
}
It does seem as though the answer was not that different from what I was doing, but it does work!

C# process RedirectStandardOutput not redirecting

I want to redirect standardoutput of a Process in a richTextBox. Here is my process configuration,
string command = "/K perl C:\\Server.pl ";
ProcessStartInfo startInfo = new ProcessStartInfo();
Process proc = new Process();
startInfo.WindowStyle = ProcessWindowStyle.Normal;
startInfo.FileName = "cmd.exe";
startInfo.Arguments = command;
startInfo.UseShellExecute = false;
startInfo.RedirectStandardOutput = true;
proc.StartInfo = startInfo;
proc.OutputDataReceived += (s, ea) => this.richTextBox1.AppendText(ea.Data);
proc.Start();
proc.BeginOutputReadLine();
Here is my Server.pl file
print "Server1 \n";
while(1)
{
print "Server \n";
sleep 1;
}
But when I run the program the cmd.exe is just black and nothing printed in richTextBox. but when I change the
startInfo.RedirectStandardOutput = false;
I have this out put in my cmd.exe:
Server1
Server
Server
Server
...
How I can work around this issue ?
Might be as simple as disabling output buffering in your perl script. This is done using the $| special variable (see perlvar).
$| = 1;
print "Server1 \n";
...

Executing batch file command within C#

I have the following code in my C# application which loaded a batch file silently using command prompt and executed and returned the result to a string:
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.FileName = #"C:\files\send.bat";
proc.StartInfo.RedirectStandardError = false;
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.CreateNoWindow = true;
proc.Start();
string strGetInfo = proc.StandardOutput.ReadToEnd();
strCMDOut = strGetInfo.Substring(strGetInfo.Length - 5, 3);
proc.WaitForExit();
I am trying to avoid my application going out to a different file to execute the batch file, rather I wanted to embed it inside my application. So I changed the above code to this:
System.Diagnostics.Process proc = new System.Diagnostics.Process();
System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
startInfo.FileName = "cmd.exe";
startInfo.Arguments = "#ECHO ON java com.this.test567 send";
startInfo.RedirectStandardOutput = true;
startInfo.UseShellExecute = false;
proc.StartInfo = startInfo;
proc.Start();
string strGetInfo = proc.StandardOutput.ReadToEnd();
strCMDOut = strGetInfo.Substring(strGetInfo.Length - 5, 3);
When the code executes, I can see the command prompt window for a brief moment before it closes and the execution is not working correctly. How can I fix the issue?
Instead of using cmd.exe just use java directly, you should also redirect standard error and check that after the process ends.
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.FileName = #"java.exe";
proc.StartInfo.Arguments = "com.this.test567";
proc.StartInfo.RedirectStandardError = true;
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.CreateNoWindow = true;
proc.Start();
string strGetInfo = proc.StandardOutput.ReadToEnd();
if(string.IsNullOrEmpty(strGetInfo))
strGetInfo = proc.StandardError.ReadToEnd();
proc.WaitForExit();
Note that by calling cmd directly, you're effectively making a batch script with whatever you use for in the Arguments Property. Like a .bat file, the command window closes as soon as it's done. To fix this, add a pause command to the end.
startInfo.Arguments = "#ECHO ON java com.this.test567 send\npause";
& seperates commands on a line.
&& executes this command only if previous command's errorlevel is 0.
|| (not used above) executes this command only if previous command's errorlevel is NOT 0
> output to a file
>> append output to a file
< input from a file
| output of one command into the input of another command
^ escapes any of the above, including itself, if needed to be passed to a program
so seperate commands with &
"/k #ECHO ON&java com.this.test567&send"
/k keeps a window open.
so you'll get in cmd
cmd /k #ECHO ON&java com.this.test567&send

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