exec does not execute a command in your shell

try

CopyProcess p = Runtime.getRuntime().exec(new String[]{"csh","-c","cat /home/narek/pk.txt"});

instead.

EDIT:: I don't have csh on my system so I used bash instead. The following worked for me

CopyProcess p = Runtime.getRuntime().exec(new String[]{"bash","-c","ls /home/XXX"});

I am not sure if you are asking about Shell command execution, or ipconfig in general.

If the first is the case here: Yep, you can use Runtime.getRuntime.exec(). Related Answers (In Stackoverflow):

1. Executing shell commands from Java
2. Want to invoke a linux shell command from Java

Moreover to the answers provided there, here is my example on how you do it with "host -t a" command for DNS lookups. I would generally recommend to read through the list you get and append them in an String for logging purposes.

p = Runtime.getRuntime().exec("host -t a " + domain);
p.waitFor();
     
BufferedReader reader = 
  new BufferedReader(new InputStreamReader(p.getInputStream()));
     
String line = "";           
while ((line = reader.readLine())!= null) {
    sb.append(line + "\n");
}

The other solution which herausuggested was to use ProcessBuilderand execute the command from there. For this you need to use Java SE 7 upwards. Here is an example that starts a process with a modified working directory and environment, and redirects standard output and error to be appended to a log file:

 ProcessBuilder pb =
   new ProcessBuilder("myCommand", "myArg1", "myArg2");
 Map<String, String> env = pb.environment();
 env.put("VAR1", "myValue");
 env.remove("OTHERVAR");
 env.put("VAR2", env.get("VAR1") + "suffix");
 pb.directory(new File("myDir"));
 File log = new File("log");
 pb.redirectErrorStream(true);
 pb.redirectOutput(Redirect.appendTo(log));
 Process p = pb.start();
 assert pb.redirectInput() == Redirect.PIPE;
 assert pb.redirectOutput().file() == log;
 assert p.getInputStream().read() == -1;

If you wanna know more about ProcessBuilder, read through the documentation: Oracle Documentation on Class ProcessBuilder

You won't be able to run commands that affect the current invoking shell, only to run command line bash/cmd as sub-process from Java and send them commands as follows. I would not recommend this approach:

CopyString[] cmd = new String[] { "/bin/bash" }; // "CMD.EXE"
ProcessBuilder pb = new ProcessBuilder(cmd);

Path out = Path.of(cmd[0]+"-stdout.log");
Path err = Path.of(cmd[0]+"-stderr.log");
pb.redirectOutput(out.toFile());
pb.redirectError(err.toFile());

Process p = pb.start();
String lineSep = System.lineSeparator(); 

try(PrintStream stdin = new PrintStream(p.getOutputStream(), true))
{
    stdin.print("pwd");
    stdin.print(lineSep);
    stdin.print("cd ..");
    stdin.print(lineSep);
    stdin.print("pwd");
    stdin.print(lineSep);
};
p.waitFor();
System.out.println("OUTPUT:"+Files.readString(out));
System.out.println("ERROR WAS: "+Files.readString(err));

}

This also works for CMD.EXE on Windows (with different commands). To capture the response per command you should replace use of pb.redirectOutput() with code to read pb.getInputStream() if you really need the responses per line rather than as one file.