Develop Reference

Adding double quotes symbol in ProcessBuilder

I am using ProcessBuilderto build my command. I want to build my command following this post:How do I launch a java process that has the standard bash shell environment?
Namely, my command is something like this:
/bin/bash -l -c "my program"
However, I am having difficulties to pass the double quotes into ProcessBuilder, as new ProcessBuilder(List<String> command) failed to phrase the command if I natively add double quotes to List<String> command. ProcessBuilder recognizes the double quotes as an argument.
Relevant code:
//Construct the argument
csi.add("/bin/bash");
csi.add("-l");
csi.add("-c");
csi.add("\"");
csi.add(csi_path);
csi.add(pre_hash);
csi.add(post_hash);
csi.add("\"");
String csi_output = Command.runCommand(project_directory, csi);
public static String runCommand(String directory, List<String> command) {
ProcessBuilder processBuilder = new ProcessBuilder(command).directory(new File(directory));
Process process;
String output = null;
try {
process = processBuilder.start();
//Pause the current thread until the process is done
process.waitFor();
//When the process does not exit properly
if (process.exitValue() != 0) {
//Error
System.out.println("command exited in error: " + process.exitValue());
//Handle the error
return readOutput(process);
}else {
output = readOutput(process);
System.out.println(output);
}
} catch (InterruptedException e) {
System.out.println("Something wrong with command: " +e.getMessage());
} catch (IOException e) {
System.out.println("Something wrong with command: " +e.getMessage());
}
return output;
}
Ps: I do want to use ProcessBuilder instead of Runtime.getRuntime.exec() because I need to run the command in a specific directory. I need to use ProcessBuilder.directory().
Ps: The command will exit with 2 after running. It seems that the system can recognize this command. The strange thing is that it has no output after exiting with 2.
Ps: The expected command is /bin/bash -l -c "/Users/ryouyasachi/GettyGradle/build/idea-sandbox/plugins/Getty/classes/python/csi 19f4281 a562db1". I printed the value and it was correct.

Best way to troubleshoot your problem is to construct the command first and pass it to the list. So, instead of doing all this.
csi.add("/bin/bash");
csi.add("-l");
csi.add("-c");
csi.add("\"");
csi.add(csi_path);
csi.add(pre_hash);
csi.add(post_hash);
csi.add("\"");
You should first construct the command
StringBuilder sb = new StringBuilder();
sb.append("/bin/bash -l -c");
sb.append("\""+csi_path+pre_hash+post_hash+"\"");// add whitespace between the varaible, if required.
System.outprintln(sb.toString()); //verify your command here
csi.add(sb.toString());
Also, verify all above variable values.

Thx for #Ravi 's idea!
//Construct the argument
csi.add("/bin/bash");
csi.add("-l");
csi.add("-c");
csi.add("\"" + csi_path + " " + pre_hash+ " " + post_hash + "\"");
String csi_output = Command.runCommand(project_directory, csi);
The Process has to take each argument separately in order to recognize the command. The tricky part is that, in my desired command
/bin/bash -l -c "/mypath/csi"
"/mypath/csi" needs to be viewed as one single argument by Process.

Running command from java produces empty output

I need to run the below comand using java but it is running fine in terminal as
svn list http://192.168.0.19/svn/cc/Branch/Jobs/tt/jobs/ --username prasadh --password prasadh2k > output.txt
But when running the same via process builder it is returning empty result.
My code:
ProcessBuilder pb = new ProcessBuilder("cmd", "C:\\Users\\dev112\\output", "svn", "list", "http://192.168.0.19/svn/cadgraf/Branch/Jobs/T0003SATHYABAMAT/Completedjobs", "--username", "prasadh", "--password", "prasadh2k", ">", "output.txt");
pb.redirectErrorStream(true);
try {
Process p = pb.start();
new Thread(new InputConsumerforImageMagick.InputConsumer(p.getInputStream())).start();
try {
System.err.println("Exited with: " + p.getErrorStream());
} catch (Exception ex) {
Logger.getLogger(AddImage.class.getName()).log(Level.SEVERE, null, ex);
}
} catch (IOException ex) {
Logger.getLogger(AddImage.class.getName()).log(Level.SEVERE, null, ex);
}

I/O redirection doesn't work well with ProcessBuilder. You should either call cmd.exe with
new ProcessBuilder("cmd", "/c", "svn ... > output.txt");
(i.e. you have to call cmd with exactly two arguments)
or you must redirect yourself, that is you need to start a background thread which reads stdout from the process and writes it to output.txt. In that case, you should use:
new ProcessBuilder("svn", "list", ...);
The former is brittle when you have spaces in arguments. So I suggest the latter even though the Java code is much more complex.
You should also have a look at Commons Exec which makes it much easier to deal with external processes.
Or with Java 7, you can use pb.redirectOutput();

Don't go through cmd. Just run the command directly:
final Path cwd = Paths.get("c:\\Users\\dev112\\output");
Files.createDirectories(cwd);
final Path outfile = cwd.resolve("output.txt");
final ProcessBuilder pb = new ProcessBuilder("svn", "list",
"http://192.168.0.19/svn/cadgraf/Branch/Jobs/T0003SATHYABAMAT/Completedjobs",
"--username", "prasadh", "--password", "prasadh2k");
pb.directory(cwd.toFile());
pb.redirectOutput(outfile.toFile());
final int retcode = pb.start().waitFor();
What is more, why do you get the process' standard output if you output to a file? Do one or the other, not both. If you output to a file then read the contents of that file after the command is executed.
The sample above outputs to a file; just open a stream to that file afterwards using Files.newInputStream(outfile) (well, that is, if retcode is 0; if it isn't, your command has ended with an error; which also means that you should redirect stderr somewhere, too)

This works for me:
String command = "svn list http://192.168.0.19/svn/cc/Branch/Jobs/tt/jobs/ --username prasadh --password prasadh2k";
ProcessBuilder processBuilder = new ProcessBuilder(command.split());
processBuilder.redirectOutput(new File("C:/Users/dev112/output/", "output.txt"));
processBuilder.start();

Command line argument works in console, fails from within Runtime.getRuntime().exec

Trying to build a basic launcher for a java game. I'm building the proper command to run the application. When the following command executes in the launcher, the launcher closes as expected, but the command doesn't appear to work - either it doesn't work or the game launches and immediately crashes.
When I print this same command to the console and copy/paste it into console and execute manually, it works perfectly.
/**
*
*/
protected void launch(){
currentStatusMsg = "Launching...";
String cmd = "java -jar";
cmd += " -Djava.library.path=\"" +nativesDirectory.getAbsolutePath() + "\"";
cmd += " \""+applicationJar.getAbsolutePath() + "\"";
System.out.println(cmd);
try {
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(cmd);
//closeLauncher();
BufferedReader input = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line=null;
while((line=input.readLine()) != null) {
System.out.println(line);
}
int exitVal = pr.waitFor();
System.out.println("Exited with error code "+exitVal);
} catch(Exception e) {
System.out.println(e.toString());
e.printStackTrace();
}
}
I tried adding something to read the output, but nothing is printed.
I was originally using the following format instead, but it has the same effect:
Process pr = Runtime.getRuntime().exec(new String[]{
"java",
"-Djava.library.path=\"" +nativesDirectory.getAbsolutePath() + "\"",
"-jar",
applicationJar.getAbsolutePath()});
Update I realized I was closing the launcher before allowing the debug code to run. The system only prints: "Exited with error code 1"
I finally was able to get the subprocess error to print. It states:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no lwjgl in java.library.path
However, it should be available because the command I'm executing includes the library path, and when this exact command is run manually, it works fine.

the java command launcher is not a shell. don't use quoting and space separated commands because it won't end well. put each argument into a separate String without any extra quoting, and use the exec(String[]) method.

Executing command in cmd and showing output in jTextArea of swing GUI application

I am developing a swing gui application in which i want to execute some cmd commands and show their output in a jTextArea and i also want to enter values asked during program execution in a jTextField. Plase provide some code which can help me to achive my goal.

This code should get you started with executing cmd commands from java and capturing their output:
import java.io.InputStream;
public class CmdProxy {
public static void main(String [] args) {
try {
Process proc = Runtime.getRuntime().exec("cmd /C \"dir \\ \"");
InputStream is = proc.getInputStream();
// NOTE: this is not the most elegant way to extract content from the
// input stream
int i = -1;
StringBuilder buf = new StringBuilder();
while ((i = is.read()) != -1) {
buf.append((char)i);
}
proc.waitFor();
System.out.println(buf.toString());
} catch (Throwable t) {
t.printStackTrace();
}
}
}
Try it in your sandbox and see what happens. Note that the /C option ensures the cmd process terminates after it is done handling the command arguments we passed (in this case, "dir \ "). In your case you want to exec "cmd /C \"" + whateverUserSpecified + "\"". Obviously, I'm assuming you're programming in/for a Window's environment. I'll let you or someone else figure out the GUI code.

How can I launch VI from within Java under commons-exec?

I would like to be able to launch VI from within my Java program and wait for the user to quit VI before proceeding. Here's the code snippet that I have currently:
...
String previewFileName="test.txt"; // the file to edit
CommandLine cmdLine = new CommandLine("/usr/bin/vi");
cmdLine.addArgument(previewFileName);
cmdLine.addArgument(">/dev/tty");
cmdLine.addArgument("</dev/tty");
Executor executor = new DefaultExecutor();
try
{
DefaultExecuteResultHandler resultHandler = new ResetProcessResultHandler(cmdLine);
executor.execute(cmdLine, resultHandler);
} catch (IOException e)
{
throw new Error("Cannot execute command: /usr/bin/vi " + previewFileName, e);
}
log.info("waiting...");
cmdLine.wait();
log.info("...done");
...
private class ResetProcessResultHandler extends DefaultExecuteResultHandler
{
private final CommandLine mCommandLine;
public ResetProcessResultHandler(CommandLine pCommandLine)
{
mCommandLine = pCommandLine;
}
public void onProcessComplete(int exitValue)
{
log.info("Command complete rc(" + exitValue + ")");
if (exitValue != 0)
{
throw new RuntimeException("VI command error [rc=" + exitValue + "] " );
}
mCommandLine.notify();
}
public void onProcessFailed(ExecuteException e)
{
if (e.getExitValue() != 0)
{
log.error("launch VI error " + e.toString());
throw new RuntimeException("VI command failed [" + e.getCause() + "] ");
}
else
{
log.info("VI complete rc(" + e.getExitValue() + ")");
}
mCommandLine.notify();
}
}
I receive output:
Vim: output is not to a terminal
Vim: input is not from a terminal
But then I see the screen painted as if VI had started; and VI doesn't read characters I type.
So ... redirecting from /dev/tty isn't doing the trick.
Someone must have done this before - help!
Thanks,
Mark

However since Java 1.7 you can use the next example to transparently redirect and have full console functionality
System.out.println("STARTING VI");
ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/vi");
processBuilder.redirectOutput(ProcessBuilder.Redirect.INHERIT);
processBuilder.redirectError(ProcessBuilder.Redirect.INHERIT);
processBuilder.redirectInput(ProcessBuilder.Redirect.INHERIT);
Process p = processBuilder.start();
// wait for termination.
p.waitFor();
System.out.println("Exiting VI");
This will allow you to open VI transparently for JVM 1.7+.

When Java runs a program via Runtime.exec() (and this is what commons-exec does in the end), it connects the program's input, output and error streams to your Java app as input/output streams. Such a stream is certainly not a terminal, you can't for example move the text cursor in it (since it doesn't have any), change text colors, or detect if Shift key is pressed (since it's just a stream of bytes and not a physical keyborad). So, an interactive app like vi can't really function under such conditions like in a terminal.
By the way, I'm not sure if the command line args you supply are parsed by the shell or passed directly to the program. In the latter case your redirection to /dev/tty couldn't possibly work even if there was a way for Java to somehow allow the program to replace Java's connected streams with something else.
As an aside, it seems a bit strange why you would like to run vi from inside a Java program.
So I guess the best solution is to execute a terminal emulator like konsole or gnome-terminal or xterm and let it run vi by passing corresponding argument on its command line (e.g. konsole -e vi). In this case the terminal's window should pop up and vi could function inside it. Of course, it won't work if you're on a headless server, but then running vi can't be useful anyway.

I'm not sure how to do it with commons-exec,
But standard Java should be something along the lines of...
String[] command = {"/usr/bin/vi", "test.txt"};
Process vimProcess = Runtime.getRuntime().exec(command);
vimProcess.waitFor();
This will cause the current thread to wait for the process to complete. You can also use
vimProcess.getInputStream(), getOutputStream() and getErrorStream() to redirect those to log files or wherever you want it to go.
See here for more details.
http://docs.oracle.com/javase/6/docs/api/java/lang/Runtime.html
Hopefully this helps.