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

Question

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?

The command `start` given to CMD.EXE causes your CMD.EXE to launch a new command window. That means you have 2 CMD.EXE processes and Java knows nothing of the second one. — DuncG, Dec 15 '21 at 18:06

score 0 · Accepted Answer · answered Dec 15 '21 at 18:30

0

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");

answered Dec 15 '21 at 18:30

DuncG

12,137
2
21
33

thanks,i try to test it, but didnt work, just black cmd – Ddll Dec 15 '21 at 18:40

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

1 Answers1