Develop Reference

Run nodejs using java

I need to run some node.js program using java
my code looks like this
String filePath= "/home/gilles/eclipse-workspace/informationGewinnungApp/videotool/src/videotool.js";
String option1 = "-m resources/WetterBerich";
String option2 = "--bg_content resources/logo.png";
ProcessBuilder Pb =
new ProcessBuilder("node",filePath+option1+option2);
Map<String, String> env = pb.environment();
env.put("VAR1", "myValue");
env.remove("OTHERVAR");
env.put("VAR2", env.get("VAR1") + "suffix");
pb.directory(new File("/usr/bin"));
File log = new File("log");
// pb.redirectErrorStream(true);
pb.redirectError(ProcessBuilder.Redirect.INHERIT);
pb.redirectOutput(Redirect.appendTo(log));
Process p = pb.start();
assert pb.redirectInput() == Redirect.PIPE;
assert pb.redirectOutput().file() == log;
assert p.getInputStream().read() == -1;
but I get this Error
module.js:549
throw err;
^

Mostly dupe: Cannot ProcessBuilder to execute command for ffmpeg -i shortWav.wav -af silenceremove=1:0:-50dB shortWavCued.mp3
You are putting multiple (all) options in ONE argument.
When you give a command line node this that to a shell, it passes this and that to node as separate arguments, and that is how node expects to receive them. ProcessBuilder does not split strings into separate arguments like a shell does, you must do it:
ProcessBuilder Pb = new ProcessBuilder("node",filePath,
"-m", "resources/WetterBerich",
"--bg_content", "resources/logo.png");
PS: using /usr/bin for your working directory is typically not a good idea.

how to run vb exe file from java server side with parameters

I am writing a java server process that in addition should run vb.exe file with parameters in windows only.
I tried to use ProcessBuilder with start function and Process with exec function but I have no error but nothing happens!
the cmd for example:
"C:\AL500\BIAFLABEL\AddToQueue.exe" "C:\AL500\BiafLabel\Templates\2.xml" -printer \\mickaelbpc\System-N
the command line definitions in the code:
String fullcmd = "\"C:\\AL500\\BIAFLABEL\\AddToQueue.exe\" \"C:\\AL500\\BiafLabel\\Templates\\2.xml\" -printer \\\\mickaelbpc\\System-N";
String fullcmd1 = "C:\\AL500\\BIAFLABEL\\AddToQueue.exe C:\\AL500\\BiafLabel\\Templates\\2.xml -printer \\\\mickaelbpc\\System-N";
String cmd1 = "C:\\AL500\\BIAFLABEL\\AddToQueue.exe";
String cmd2 = "C:\\AL500\\BiafLabel\\Templates\\2.xml";
String cmd3 = "-printer";
String cmd4 = "\\\\mickaelbpc\\System-N";
String[] command = new String[]{cmd1, cmd2, cmd3,cmd4};
Process + array:
File dir = new File("C:/workspace");
Process process = Runtime.getRuntime().exec(command, null, dir);
process.waitFor();
InputStream stdout = process.getInputStream();
InputStream stderr = process.getErrorStream();
String strData;
StringBuffer sb = new StringBuffer("");
BufferedReader brData = new BufferedReader(new
InputStreamReader(stdout));
while ((strData = brData.readLine()) != null)
{
sb = sb.append(strData).append("\r\n");
}
brData.close();
ProcessBuilder + string command with ":
ProcessBuilder pb=new ProcessBuilder(fullcmd);
pb.redirectErrorStream(true);
Process process1=pb.start();
BufferedReader inStreamReader = new BufferedReader(
new InputStreamReader(process1.getInputStream()));
String line;
while (true) {
line = inStreamReader.readLine();
if (line == null) { break; }
System.out.println(line);
ProcessBuilder + string command with no ":
File log = new File("log");
ProcessBuilder pb=new ProcessBuilder(/*command*/fullcmd1);
pb.redirectErrorStream(true);
pb.redirectOutput(Redirect.appendTo(log));
Process process1=pb.start();
BufferedReader inStreamReader = new BufferedReader(
new InputStreamReader(process1.getInputStream()));
String line;
while (true) {
line = inStreamReader.readLine();
if (line == null) { break; }
System.out.println(line);
}
after the changes I am getting this error: "java.io.IOException: Cannot run program "C:\AL500\BIAFLABEL\AddToQueue.exe C:\AL500\BiafLabel\Templates\2.xml -printer \mickaelbpc\System-N": CreateProcess error=2, The system cannot find the file specified" can you please advise?
ProcessBuilder with cmd.exe:
ProcessBuilder pb=new ProcessBuilder("cmd.exe","/c",fullcmd);
pb.redirectErrorStream(true);
Process process1=pb.start();
BufferedReader inStreamReader = new BufferedReader(
new InputStreamReader(process1.getInputStream()));
String line;
while (true) {
line = inStreamReader.readLine();
if (line == null) { break; }
System.out.println(line);
}
I did all the options and more...if it will be necessary I will add more examples
the vb exe should print a file. any idea how to run it from java process? or what is wrong with my code?

Study the error and output stream of the command. Need to redirect them and stream them in a separate thread. Or try this fronm
File log = new File("log");
pb.redirectErrorStream(true);
pb.redirectOutput(Redirect.appendTo(log));
Is the full path correct? Can you print the commad line space seperated to a file called run.cmd and run that manually and see what happens from prompt?
which directory are you starting the process from might have to be different than the one that your java program is running at? Process builder has a https://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html#directory()
To know which directory your java program is using do this:
File f = new File("./");
try{
System.out.println("Start dir is :" + f.getCanonicalFile());
}catch...
https://docs.oracle.com/javase/7/docs/api/java/io/File.html#getCanonicalFile()
i do not think you do not need to add quotes, just set them in the array with actual values. but if running from a .cmd you will need to qualify params with spaces by putting quotes. best to have no spaces in the paths or params when testing.
See github.com/tgkprog/nli/blob/master/RunCmd.java if ur redirecting to log, dont get the stream again in your loop. and dont call via cmd.exe. in my example ignore the actual commmand, put ur exe and params, i just called a sh file as on ubuntu. You call with your 4 params

Error when using linux grep command in java

I'm trying to get the output of grep linux shell command in java by using process builder. But i got a stuck in this case. Please help me.
Thank in advice!
String[] args = new String[7];
args[0] = "/bin/bash";
args[1] = "-c";
args[2] = "grep";
args[3] = "-n";
args[4] = "-e";
args[5] = "KERNELVERSION";
args[6] = kernelFilePath.trim();
ProcessBuilder pb;
Process process = null;
try {
pb = new ProcessBuilder(args);
pb = pb.directory(new File(directory));
pb.inheritIO();
pb.redirectOutput(ProcessBuilder.Redirect.INHERIT);
pb.redirectError(ProcessBuilder.Redirect.INHERIT);
process = pb.start();
process.waitFor();
} catch (IOException | InterruptedException e) {
System.out.println("executeCmdWithOutput() exception : " + e.toString());
} finally {
if (process != null) {
process.destroy();
}
}
==> Error:
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.
I tried the command in bash and it worked fine:
grep -n -e KERNELVERSION ..../Makefile

Have you tried change the args[2] as full command?
Also, you can use pgrep, it does not require you to use pipe.

You don't need to explicitly run /bin/bash in order to execute the grep process. Just call it directly and ProcessBuilder will run it:
String[] args = {"grep", "-n", "KERNELVERSION", kernelFilePath.trim()};
Also, you don't need to use the -e option, unless there are multiple patterns that you are searching for.
If you really wanted to run grep in /bin/bash:
String[] args = {"/bin/bash", "-c", "grep -n KERNELVERSION " + kernelFilePath.trim()};
passes a single argument to bash containing the full command and arguments to execute.

Run exec file using Java on Mac

I need to start a server using bash, so I had created an UNIX shell , but I am not able to execute it with Java from Eclipse.
I tried the following code which doesn't work :
Process proc = Runtime.getRuntime().exec(./startServer);
Here is content of the startServer file :
#!/bin/bash
cd /Users/sujitsoni/Documents/bet/client
npm start

You can try the following two options.
Option 1
Process proc = Runtime.getRuntime().exec("/bin/bash", "-c", "<Abosulte Path>/startServer");
Option 2
ProcessBuilder pb = new ProcessBuilder("/bin/bash", "-c", "<Absolute Path>/startServer");
pb.directory(new File("<Absolute Path>"));
Process proc = pb.start();

A couple Of things can go wrong:
The path to the file you have given might be wrong for eclipse it can take relative path but from the command line, it will take the absolute path.
error=13, Permission denied - If the script file doesn't have required permissions. In your scenario, that might not the case as you are not getting any error.
At last, you are executing the script by java program so the output of your script will not be printed out. In your scenario, this might be the case. You need to capture the output of script from BufferedReade and print it. ( In your case server might have started but you are not seeing the logs/output of the script.
See the code sample below for printing output.
public static void main(String[] args) throws IOException, InterruptedException {
Process proc = Runtime.getRuntime().exec("./startServer");
proc.waitFor();
StringBuffer output = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line = "";
while ((line = reader.readLine()) != null) {
output.append(line + "\n");
}
System.out.println(output);
}

Java process gets stuck [duplicate]

I was trying to build up a ProcessBuilder calling the ffmpeg binary.
My problem is that calling it, it returns perfectly under MacOs, Ubuntu and WindowsXp,
but under Windows7 the waitFor() never returns.
Has anyone similar experience under windows 7? Any help would be appreciated!
My command:
ProcessBuilder pb = new ProcessBuilder( );
pb.command( "C:\\Windows\\System32\\cmd.exe", "/c", "c:\\ffmpeg\\bin\\ffmpeg.exe", "-version" );
Tried these ones too:
pb.command( "c:\\ffmpeg\\bin\\ffmpeg.exe", "-version" );
pb.command( "C:\\Windows\\System32\\cmd.exe", "/c", "start c:\\ffmpeg\\bin\\ffmpeg.exe -version" );
Result is the same. :(

Looks like your process writes something in its out and/or err streams. Their buffer overflow and process blocks. You should read out and err streams of your process to avoid this.
See "When Runtime.exec() won't" for more information

If you are using java 7 you could do something like that :
File encodingFile = new File(outfile + ".encoding");
ProcessBuilder pb = new ProcessBuilder(vars.config.ffmpeg, "-i", file, "-y", "-s", width + "x" + height, "-vcodec", "libvpx", outfile); //or other command....
encodingFile.createNewFile();
pb.redirectErrorStream(true);
pb.redirectInput(ProcessBuilder.Redirect.PIPE); //optional, default behavior
pb.redirectOutput(encodingFile);
Process p = pb.start();
// if you want to wait for the process to finish
p.waitFor();
encodingFile.delete();

you should do something like this
ProcessBuilder pb = new ProcessBuilder( );
pb.command( "C:\\Windows\\System32\\cmd.exe", "/c",
"c:\\ffmpeg\\bin\\ffmpeg.exe", "-version" );
Process process = pb.start();
OutputStream stdOutput = process.getOutputStream();
InputStream inputStream = process.getInputStream();
InputStream errorStream = process.getErrorStream();
then it will work as your process is giving some output but you are not reading it