Runtime.getRuntime().exec(), hide the console screen

Question

I am executing a batch file using Java code. The code is given below:

Process proc = null;

proc = Runtime.getRuntime().exec("cmd /c start somebat.bat");

With this, the normal command prompt screen gets open. Now I want to suppress/hide the command prompt window(the black one). I found somewhere that if I remove the start attribute from the command, it doesn't appear but when removing it from the command, the command doesn't executes and no exceptions are also shown.

Can any body tell me how to suppress this window?

Answer 1

I dont know windows very well, but I suggest you omit the "cmd" bit of the command. cmd.exe is the windows terminal. Just a guess. Look up the other exec() methods, there is one which takes the command executable to run, and the arguments. On UNIX at least, you can't normally do anything a shell doesn't support (like piping the output to a file) since those are shell features and not done by the called program. Could be why you find if you remove the cmd prefix some things don't work.

try just:

Process proc = Runtime.getRuntime().exec("somebat.bat");

Answer 2

Add /Q

Runtime.getRuntime().exec( "cmd /c /Q start somebat.bat");

Answer 3

Have you tried

start /min "title" "c:\path\batchfile.bat"

This will run your batch file without the window. It will still appear in the taskbar, however (since it's minimised)

Answer 4

Have a look at this forum post. One of the answers suggest to use a vbs script to hide the window.

Answer 5

Have you tried the B option of "start"?

proc = Runtime.getRuntime().exec("cmd /c start /B somebat.bat");

Edit:
Ok, Anish, that is funny that your code is not executed.
I set up a unit test:

Process proc = null;
 try
 {
  proc = Runtime.getRuntime().exec("cmd /c start /B D:\\temp\\_test\\somebat.bat");
  proc = Runtime.getRuntime().exec("cmd /c call D:\\temp\\_test\\somebat.bat");
  proc = Runtime.getRuntime().exec("D:\\temp\\_test\\somebat.bat");
 }
 catch (IOException e)
 {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }

My somebat.bat file looks like this:

rem somebat.bat:
d:
cd D:\temp\_test
copy somebat.bat somebat2.bat

All three versions in the try-block above work in my scenario. Somebat.bat is copied to somebat2.bat without a command window popping up (what happens, if I use your call, shown in your question).

Edit 2: Next round ;-)
Anish, can you show us how your somebat.bat and your ant file looks like?
Because all of the three calls below work in my scenario:

test code:

Process proc = null;
proc = Runtime.getRuntime().exec("cmd /c start /B c:\\temp\\_test\\somebat.bat");
proc = Runtime.getRuntime().exec("cmd /c call c:\\temp\\_test\\somebat.bat");
proc = Runtime.getRuntime().exec("c:\\temp\\_test\\somebat.bat");

somebat.bat:

cd\temp\_test  
ant mycopy

build.xml:

<?xml version="1.0"?>
<project name="testproj" default="mycopy" basedir=".">
  <target name="mycopy">
      <copy file="myfile.txt" tofile="mycopy.txt" />
  </target>
</project>

myfile.txt: arbitrary text file

Answer 6

Hi John,

The ant command looks like:

ant -lib ./ant-lib -f checkstyle_build.xml -verbose -Dcode.location=%1 -Dcode.dir=%2 %3

where %1, %2, %3 are the arguements given when running the batch file. I also tried putting the arguements directly in the call above but then also its not running.

Thanks for so much effort you putting on giving me the resolution. I really appreciate it.

Regards

Anish