Java runtime exec and pipe

[erotavlas]

Hi,

I'm newbie of Java and I have a trouble on executing a command of shell where I use a pipe. I read on the web that it is possible to do something like this:


String[] cmd = {
"/bin/sh",
"-c",
"ls /etc | grep release"
};

Process p = Runtime.getRuntime().exec(cmd);


This works well. If I try something more complex like this


ssh user@ip 'tar -jcf - file1 file2 ' | tar -C /path -jxf -

it does not work and I receive the exit code 255. Do you have any idea?

Thank you

[spjackson]

Please show what you are putting in String[] cmd for this more complex form.

[erotavlas]

I tried this


String[] cmd = {
"/bin/sh",
"-c",
"ssh user@ip 'tar -jcf - file1 file2 ' | tar -C /path -jxf -"
};
Process p = Runtime.getRuntime().exec(cmd);


and also this


String cmd = "/bin/sh -c ssh user@ip 'tar -jcf - file1 file2 ' | tar -C /path -jxf -";
Process p = Runtime.getRuntime().exec(cmd);

but both the solutions don't work.

[spjackson]

The following works for me using authorized keys; I struggle to guess why it doesn't work for you. Does your command work from the command line? If tar or ssh weren't installed then you'd get an error!


import java.io.IOException;

public class Call {

public static void main(String[] args) throws IOException, InterruptedException {

String[] cmd = {
"/bin/sh",
"-c",
"ssh me@myhost 'tar -jcf - file1 file2 ' | tar -C ./foo -jxf -"
};

Process proc = Runtime.getRuntime().exec(cmd);
System.out.print("Exit code: ");
System.out.println(proc.waitFor());
}
}