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Can't save mysql dump file to my hard drive from a java progam [duplicate]

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" });

C program compilation from a java program

I am trying to compile a c program from a java program on Linux platform. My snippet is.
ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/gcc",
"-c","/hipad/UserProject/example.c");
Process proc = processBuilder.start();
There is no error during compilation of java program but I am not able to get .o file. I tried to find out solutions but no one is working.
Any suggestion.....

The default working directory of a child process is what ever directory the Java process has as a working directory, which usually is where it was launched from. And by default gcc writes output files to current working directory. That's where you should find example.o.
There are two simple ways to solve this. You can give gcc -o option and full path and name of desired output file, or you can set working directory of child process, like this:
ProcessBuilder processBuilder =
new ProcessBuilder("/usr/bin/gcc", "-c","example.c"); // source in working dir
processBuilder.directory(new File ("/hipad/UserProject")); // or whatever
Process proc = processBuilder.start();
See ProcessBuilder javadoc for more info.

Calling python script from Java using runtime.getruntime.exec

I have a java web development project, and want to call a python script to run in the background and then carry on with the java.
String command = "cmd.exe /c cd "C:\\path\\to\\py\\" && python script.py";
Process p = Runtime.getRuntime().exec(command);
Nothing seems to happen when i call this, but i need to change directory first as the script accesses files in its directory.
Thanks for your help
Edit:
Correct answer was adding start, this is my edited code
String command = "cmd.exe /c cd "C:\\path\\to\\py\\" && start python script.py";
Process p = Runtime.getRuntime().exec(command);

Rather than using cmd to change the directory, you can set a process's working directory from the Java side. For example
ProcessBuilder pb = new ProcessBuilder("python", "script.py");
pb.directory(new File("C:\\path\\to\\py"));
Process p = pb.start();

Did you configure your environment to support "executable" python scripts?
If not, you should call it like this:
String command = "cmd.exe /c start python path\to\script\script.py";
Process p = Runtime.getRuntime().exec(command);
The start command runs the appropriate executable (in this case python interpreter), with its supplied arguments (in this case the script itself).

Using Runtime.getRuntime().exec() in Mac OS causes error

I am trying to use this code in my Java application to run another Jar in Mac OS X :
Runtime runtime = Runtime.getRuntime();
String cmd = "java -Xmx1024m -jar \"/Volumes/NANO PRO/My Program/Main.jar\"";
Process process = runtime.exec( cmd );
If Main.jar exists in a path with no spaces it will work fine, but since it exists in a path with spaces, it causes the error :
Is there a way to make this run in a path that has spaces ?

Use an array to build different parts of your command and leave it to Java runtime to convert them appropriately based on the underlying environment.
String [] cmd = {"java",
"-Xmx1024m",
"-jar",
"/Volumes/NANO PRO/My Program/Main.jar"};
Also you can take a look at ProcessBuilder:

How to run .reg file in Java

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.