Develop Reference

Problem writing data from PrintStream to "Console as Process" and not "console as System.out" in Java

in Java 8, windows 10, i have a text app, i want to open a console and write something there,
first try is:
String [] cmd = {"cmd.exe", "/c", "start"};
ProcessBuilder f = new ProcessBuilder(cmd);
f.redirectErrorStream(true);
Process p = f.start();
PrintStream printStream=new PrintStream(p.getOutputStream());
//
System.setOut(printStream);
System.out.println("this write in CMD"); //did not work
second try is:
printStream.println("this write in CMD");//did not work
Can any body Help?

Launch conhost.exe instead, and write to the stdin of the retained Process, or if you redirect your output stream to the process writes with System.out will appear in the new console window:
String [] cmd = {"conhost.exe"};
ProcessBuilder f = new ProcessBuilder(cmd);
f.redirectErrorStream(true);
Process p = f.start();
PrintStream printStream=new PrintStream(p.getOutputStream());
System.setOut(printStream);
System.out.println("dir");

The java.lang.Process is blocking the console

Is there a way around the java.lang.Process blocking the console?
In my case, when I execute the following code, my input is blocked in the console. So I can practically no longer enter anything. I've already tried a bit. For example, it doesn't work to start it in a new thread.
ProcessBuilder processBuilder = new ProcessBuilder(
"java",
"-Xms" + this.proxyConfiguration.getMemory() + "M",
"-Xmx" + this.proxyConfiguration.getMemory() + "M",
"-jar",
new File(path).getAbsoluteFile().getPath() + "//BungeeCord.jar");
processBuilder.directory(new File(path));
Process process = processBuilder.start();

Execute behind the scenes bash command from Java ProcessBuilder

I'm using in windows:
builder = new ProcessBuilder("cmd.exe", "/c", my_command);
Process p = builder.start();
i've tried to replicate that behaviour, just for macOS
i've tried theese and none of them have worked:
1. builder = new ProcessBuilder("bin/bash", "-c", my_command);
2. builder = new ProcessBuilder("osascript", my_command);
Process p = builder.start();
Will appreciate the help
Thanks

The paths you have are incorrect, they should be:
/bin/bash
and
/usr/bin/osascript

This one worked for me:
builder = new ProcessBuilder("bash", "-c", command);
Process process = builder.start();

Java switch directories and then fire command with parameters

Hey all I am trying to change directories and then run my command with parameters.
final String path = "\\Local// Apps\\IBM\\SDP\\scmtools\\eclipse";
final String command = "scm help";
final String dosCommand = "cmd /c \"" + path + "\"" + command;
final Process process = Runtime.getRuntime().exec(dosCommand);
final InputStream in = process.getInputStream();
int ch;
while((ch = in.read()) != -1) {
System.out.print((char)ch);
}
It runs without errors but outputs nothing. However, this is what shows up after it finishes:
<terminated, exit value: 0>C:\Local Apps\IBM\SDP\jdk\bin\javaw.exe (Jul 22, 2019, 11:21:37 AM)
The expected output should be:
So am I doing this correctly?
AS suggested by Andreas
Process p = null;
ProcessBuilder pb = new ProcessBuilder("scm.exe");
pb.directory(new File("C:/Local Apps/IBM/SDP/scmtools/eclipse"));
p = pb.start();
I get the following error:
Cannot run program "scm.exe" (in directory "C:\Local Apps\IBM\SDP\scmtools\eclipse"): CreateProcess error=2, The system cannot find the file specified

You should use ProcessBuilder instead of Runtime.exec, e.g.
Process proc = new ProcessBuilder("scm.exe", "help")
.directory(new File("C:\\Local Apps\\IBM\\SDP\\scmtools\\eclipse"))
.inheritIO()
.start();
proc.waitFor(); // optional
You can also go through the command interpreter if needed, e.g. if the command is a script (.bat or .cmd file):
Process proc = new ProcessBuilder("cmd", "/c", "scm", "help")
.directory(new File("C:\\Local Apps\\IBM\\SDP\\scmtools\\eclipse"))
.inheritIO()
.start();
proc.waitFor();
The inheritIO() means that you don't need to process the commands output. It will be sent to the console, or wherever Java's own output would go.

Java ProcessBuilder: OutputStream(Reader) of a process never gets ready() for *certain* commands

I've written an interface to call shell commands from Java for testing purposes. For a few commands, that works quite fine, but for others, the OutputStream of the process never gets ready(). Does anyone have an explanation ? I give the full code:
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
System.err.print("cmd: ");
String line=in.readLine();
The following are all fine for "cat -n", not for "sed s/a/e/"
ProcessBuilder pb = new ProcessBuilder(Arrays.asList(("bash -c \""+line+"\"").split(" ")));
// ProcessBuilder pb = new ProcessBuilder(Arrays.asList(("cmd /C "+line).split(" ")));
// ProcessBuilder pb = new ProcessBuilder("cmd","/C",line);
// ProcessBuilder pb = new ProcessBuilder("bash","-c",line);
// ProcessBuilder pb = new ProcessBuilder(Arrays.asList(line.split(" ")));
Interaction with the process:
pb.redirectErrorStream(true);
Process p = pb.start();
BufferedWriter toP = new BufferedWriter(new OutputStreamWriter(p.getOutputStream()));
BufferedReader fromP = new BufferedReader(new InputStreamReader(p.getInputStream()));
for(line = in.readLine(); line!=null; line=in.readLine()) {
toP.write(line+"\n");
toP.flush();
System.err.println("stdin: \""+line+"\"");
while(!fromP.ready()); // sed hangs, cat doesn't
System.out.println("result: \""+fromP.readLine()+"\"");
}
One can find plenty of information on ProcessBuilder issues, and for most of them, wrapping stdin and stdout into different Threads seems to be a solution. But if indeed this is the solution, then why ?
An further: Does anyone have an explanation why the straight-forward approach fails and under what circumstances this occurs ? From the example, I can rule out that it is the way the arguments are presented or the specific shell (cmd/bash).
I'm working with Java 1.6 on a Windows7 machine with Cygwin installed, hence both bash and cmd. Could that be a Cygwin issue ?