Executing a shell script from java using runtime.exec()

Question

Hi I am trying to create a script (test_script) and execute it -- all within one java program...
the code compiles and executes perfectly but nothing happens. This is probably because the script does not get changed to the '777' mode although i am trying to do that ... any suggestions ???
//code
import java.io.*;
import java.util.*;
public class ScriptBuilder
     public ScriptBuilder() {
     public void writeScript() throws java.io.IOException{
     FileWriter writer = new FileWriter(new File("test_script"));
          writer.write("#! /bin/sh\n");
          writer.write("cd prodiags\n");
          writer.write("tar cvf delTask.tar delTask\n");
          writer.write("rm -rf delTask\n");          
          writer.flush();
          writer.close();
Runtime rt= Runtime.getRuntime();
String[] cmd = new String[3];
cmd[0] = "ls";
cmd[1] = "chmod 777 test_script";
cmd[2] = "./test_script";
rt.exec(cmd);
     public static void main (String[] args)throws java.io.IOException
     ScriptBuilder sb = new ScriptBuilder();
     sb.writeScript();
}

Answer 1

I don't know exactly but the code written below is working fine try the same with your code .Even with your code instead running the code with
" ./<filename> ",if you execute it with "sh <filename>" command without changing the mode of the file it is executing properly.
import java.io.*;
import java.util.*;
public class ScriptBuilder
public ScriptBuilder()
public void writeScript() throws java.io.IOException
FileWriter writer = new FileWriter(new File("test_script"));
writer.write("#! /bin/sh\n");
writer.write("ll>/home/faiyaz/javaprac/checkll");
writer.flush();
writer.close();
Runtime rt= Runtime.getRuntime();
rt.exec("chmod 777 test_script");
rt.exec("./test_script");
} public static void main (String[] args)throws java.io.IOException
ScriptBuilder sb = new ScriptBuilder();
sb.writeScript();
}