I have made a java script which uses the runtime.exec() to execute a batch file, and that works fine but when i get the output stream and use the write() function it does not execute the command i put into it.
Runtime runtime = Runtime.getRuntime();
Process p;
p = runtime.exec("cmd /c start batchfile.bat");
out = p.getOutputStream();
out.write("command".getBytes());
It displays the batch file but does not run the command, is there another way of entering a command into the cmd running the batch file so it displays it?
With the start command, a separate command window will be opened, and any output from the batch file will be displayed there. It should also work as just cmd /c build.bat, in which case you can read the output from the subprocess in Java if desired.
You're writing into an output stream. I think you mean to write to an input stream.
Try this:
Runtime runtime = Runtime.getRuntime();
Process p;
p = runtime.exec("cmd /c start batchfile.bat");
in = p.getInputStream();
in.write("command".getBytes());
Related
Process p = Runtime.getRuntime().exec("sh somescript.sh &> out.txt");
I am running this command using Java. The script is running but it's not redirecting its stream to the file. Moreover, the file out.txt is not getting created.
This script runs fine if I run it on shell.
Any ideas?
You need to use ProcessBuilder to redirect.
ProcessBuilder builder = new ProcessBuilder("sh", "somescript.sh");
builder.redirectOutput(new File("out.txt"));
builder.redirectError(new File("out.txt"));
Process p = builder.start(); // may throw IOException
When you run a command, there is no shell running and any shell commands or functions are not available. To use something like &> you need a shell. You have one but you are not passing it to it. try instead.
Runtime.getRuntime().exec(new String[] { "sh", "somescript.sh &> out.txt" });
Process p = Runtime.getRuntime().exec("sh somescript.sh &> out.txt");
I am running this command using Java. The script is running but it's not redirecting its stream to the file. Moreover, the file out.txt is not getting created.
This script runs fine if I run it on shell.
Any ideas?
You need to use ProcessBuilder to redirect.
ProcessBuilder builder = new ProcessBuilder("sh", "somescript.sh");
builder.redirectOutput(new File("out.txt"));
builder.redirectError(new File("out.txt"));
Process p = builder.start(); // may throw IOException
When you run a command, there is no shell running and any shell commands or functions are not available. To use something like &> you need a shell. You have one but you are not passing it to it. try instead.
Runtime.getRuntime().exec(new String[] { "sh", "somescript.sh &> out.txt" });
I'm trying to run this command:
"C:\arduino\arduino --upload --board arduino:avr:nano --port COM3 -v ..\config\config.ino"
It works from my command line. It takes just a few seconds to run & finish.
The problem comes when I try to execute it from Java with:
String cmd = "C:\arduino\arduino --upload --board arduino:avr:nano --port COM3 -v ..\config\config.ino"
Process p = Runtime.getRuntime().exec(cmd);
It takes a minute to execute and ends with:
Launch 4j: an error occurred while starting the application
I've tried with ProcessBuilder too. I've also tried saving the command to a batch file and then running the batch file from Java...but I just got the same result.
EDIT:
If I run the batch file from command line it works too. As I said if I run it from Java, it doesn't.
I've realized that if I run the batch file from another batch file it doesn't work neither.
Maybe there is not a problem at all with Java, but with Arduino IDE.
EDIT 2:
Adding "start" parameter before the command and saving it to a batch file seems to work. Then you just run the batch from java.
Something like this:
arduino.bat
"start C:\arduino\arduino --upload --board arduino:avr:nano --port COM3 -v ..\config\config.ino"
Java code
String s = "PATH TO ARDUINO.BAT"
Process p = null;
ProcessBuilder pb = new ProcessBuilder(s + "arduino.bat");
pb.directory(new File(s));
p = pb.start();
I think the issue is with the relative path at -v argument. Use full path or set
actual working directory with ProcessBuilder.
I am trying to accomplish two things:
I am running cygwin on Windows7 to execute my unix shell commands and I need to automate the process by writing a Java app. I already know how to use the windows shell through Java using the 'Process class' and Runtime.getRuntime().exec("cmd /c dir"). I need to be able to do the same with unix commands: i.e.: ls -la and so forth. What should I look into?
Is there a way to remember a shell's state?
explanation: when I use: Runtime.getRuntime().exec("cmd /c dir"), I always get a listing of my home directory. If I do Runtime.getRuntime().exec("cmd /c cd <some-folder>") and then do Runtime.getRuntime().exec("cmd /c dir") again, I will still get the listing of my home folder. Is there a way to tell the process to remember its state, like a regular shell would?
It seems that the bash command line proposed by Paŭlo does not work:
C:\cygwin\bin>bash -c ls -la
-la: ls: command not found
I am having trouble figuring out the technicalities.
This is my code:
p = Runtime.getRuntime().exec("C:\\cygwin\\bin\\bash.exe -c ls -la");
reader2 = new BufferedReader(new InputStreamReader(p.getInputStream()));
line = reader2.readLine();
line ends up having a null value.
I added this to my .bash_profile:
#BASH
export BASH_HOME=/cygdrive/c/cygwin
export PATH=$BASH_HOME/bin:$PATH
I added the following as well:
System Properties -> advanced -> Environment variables -> user variebales -> variable: BASH, value: c:\cygwin\bin
Still nothing...
However, if I execute this instead, it works!
p = Runtime.getRuntime().exec("c:\\cygwin\\bin\\ls -la ~/\"Eclipse_Workspace/RenameScript/files copy\"");
1. Calling unix commands:
You simply need to call your unix shell (e.g. the bash delivered with cygwin) instead of cmd.
bash -c "ls -la"
should do. Of course, if your command is an external program, you could simply call it directly:
ls -la
When starting this from Java, it is best to use the variant which takes a string array, as then
you don't have Java let it parse to see where the arguments start and stop:
Process p =
Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe",
"-c", "ls -la"},
new String[]{"PATH=/cygdrive/c/cygwin/bin"});
The error message in your example (ls: command not found) seems to show that your bash can't find the ls command. Maybe you need to put it into the PATH variable (see above for a way to do this from Java).
Maybe instead of /cygdrive/c/cygwin/bin, the right directory name would be /usr/bin.
(Everything is a bit complicated here by having to bridge between Unix and Windows
conventions everywhere.)
The simple ls command can be called like this:
Process p = Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\ls.exe", "-la"});
2. Invoking multiple commands:
There are basically two ways of invoking multiple commands in one shell:
passing them all at once to the shell; or
passing them interactively to the shell.
For the first way, simply give multiple commands as argument to the -c option, separated by ; or \n (a newline), like this:
bash -c "cd /bin/ ; ls -la"
or from Java (adapting the example above):
Process p =
Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe",
"-c", "cd /bin/; ls -la"},
new String[]{"PATH=/cygdrive/c/cygwin/bin"});
Here the shell will parse the command line as, and execute it as a script. If it contains multiple commands, they will all be executed, if the shell does not somehow exit before for some reason (like an exit command). (I'm not sure if the Windows cmd does work in a similar way. Please test and report.)
Instead of passing the bash (or cmd or whatever shell you are using) the commands on the
command line, you can pass them via the Process' input stream.
A shell started in "input mode" (e.g. one which got neither the -c option nor a shell script file argument) will read input from the stream, and interpret the first line as a command (or several ones).
Then it will execute this command. The command itself might read more input from the stream, if it wants.
Then the shell will read the next line, interpret it as a command, and execute.
(In some cases the shell has to read more than one line, for example for long strings or composed commands like if or loops.)
This will go on until either the end of the stream (e.g. stream.close() at your side) or executing an explicit exit command (or some other reasons to exit).
Here would be an example for this:
Process p = Runtime.getRuntime().exec(new String[]{"C:\\cygwin\\bin\\bash.exe", "-s"});
InputStream outStream = p.getInputStream(); // normal output of the shell
InputStream errStream = p.getInputStream(); // error output of the shell
// TODO: start separate threads to read these streams
PrintStream ps = new PrintStream(p.getOutputStream());
ps.println("cd /bin/");
ps.println("ls -la");
ps.println("exit");
ps.close();
You do not need cygwin here. There are several pure Java libraries implementing SSH protocol. Use them. BTW they will solve your second problem. You will open session and execute command withing the same session, so the shell state will be preserved automatically.
One example would be JSch.
I need to install a .reg file (INTRANET) by using Java. How do i get my goal ?
Cheers,
You could use System.exec to launch regedit yourfile.reg
Here is how to do it :
String[] cmd = {"regedit", "yourfile.reg"};
Process p = Runtime.exec(cmd);
p.waitFor();
Last line is optional, it only allows you to wait until the operation is over.
If you're already on Java 1.6, just grab java.awt.Desktop:
Desktop.getDesktop().open(new File("c:/yourfile.reg"));
It will launch the file using the default application associated with it, as if you're doubleclicking the particular file in Windows explorer.
This can achieved through Process Builder in JAVA. Please consider the following example for this:
ProcessBuilder processBuilder = new ProcessBuilder("regedit", "reg_file_to_run.reg");
Process processToExecute = processBuilder.start();
And then you can optionally wait for the completion of process execution with this line:
processToExecute.waitFor();
Note: If command in your registry file asks for confirmation prompts while making changes in registry entries, you can perform it silently as well with '/s' option. Like this:
ProcessBuilder processBuilder = new ProcessBuilder("regedit", "/s", "reg_file_to_run.reg");
With this command would be executed silently without any confirmation prompt.