Executing shell-script with parameters from java

Question

I have been googling for some time, and everyone seems to have a different solution, none of which appear to be working for me.

I have tried both ProcessBuilder and Runtime. Both calling the .sh file directly and feeding it to /bin/bash. With no luck.

Back to basics, my current code is as follows;

String cmd[] = { "~/path/to/shellscript.sh", "foo", "bar" };
Process p = Runtime.getRuntime().exec(cmd);

Which is giving a No such file or directory error, despite that manually running;

~/path/to/shellscript.sh foo bar

Works perfectly from bash.

I need to keep the ~ because this shellscript exists in slightly different forms for three different users.

Answer 1

One option is to handle ~ yourself:

String homeDir = System.getenv("HOME");
String[] cmd = { homeDir + "/path/to/shellscript.sh", "foo", "bar" };
Process p = Runtime.getRuntime().exec(cmd);

Another is to let Bash handle it for you:

String[] cmd = { "bash", "-c", "~/path/to/shellscript.sh foo bar" };
Process p = Runtime.getRuntime().exec(cmd);

Answer 2

As already mentioned, tilde is a shell-specific expansion which should be handled manually by replacing it with the home directory of the current user (e.g with $HOME if defined).

Besides the solutions already given, you might also consider using commons-io and commons-exec from the Apache Commons project:

...
import org.apache.commons.exec.CommandLine;
import org.apache.commons.exec.DefaultExecutor;
import org.apache.commons.exec.Executor;
import org.apache.commons.io.FileUtils;
...
CommandLine cmd = new CommandLine("path/to/shellscript.sh");
cmd.addArgument("foo");
cmd.addArgument("bar");

Executor exec = new DefaultExecutor();
exec.setWorkingDirectory(FileUtils.getUserDirectory());
exec.execute(cmd);
...