Runtime.getRuntime().exec() problem while getting Mozilla version.

Question

Hi all,
I've trying to get the current mozilla version in Java side using
Runtime.getRuntime().exec(). The sample code is as below.
I've tested two cases using exec(), as case# 1 and case# 2.
The result is after the code.
try
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(new String[] {"mozilla", "-remote"}); //case# 1
//Process proc = rt.exec(new String[] {"mozilla", "-version"}); //case# 2
InputStream stderr = proc.getErrorStream();
InputStreamReader isr = new InputStreamReader(stderr);
BufferedReader br = new BufferedReader(isr);
String line = null;
System.out.println("<ERROR>");
while ( (line = br.readLine()) != null)
System.out.println(line);
System.out.println("</ERROR>");
int exitVal = proc.waitFor();
System.out.println("Process exitValue: " + exitVal);
} catch (Throwable t) {
t.printStackTrace();
// execute "mozilla -remote"(case# 1)
$ java TestExec
<ERROR>
-remote requires an argument
</ERROR>
Process exitValue: 1
// execute "mozilla -version"(case# 2)
$ java TestExec
<ERROR>
</ERROR>
Process exitValue: 0
I'm just surprised that why case# 2 couldn't get the returned version string as case #1 ? Since there will be version string be returned from command line:
$ mozilla -version
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020830, build 2002083014
Could anybody explain the problem or give any solution ?
Thanks.
-George.

Answer 1

Hi all,
One more question here.
While I use Runtime.getRuntime().exec() to execute some commands,
the commands may fail for some reason. Generally, they will return with the exit
value set to 1 or others. But sometime, before waitFor() exits, there is a popped up
dialog giving some info, and only after I click the "OK" button, it dispears, and
waitFor() returns the exit value.
So I'm not sure that could I suppress this popped up dialog, and make it run
just like other commands ? I mean, just get the exit value by waitFor() without user
interferance ?
Thanks.
-George.