Calling shell commands and execute shell scripts in java

Calling shell commands and execute shell scripts in java

1. Enter the command sudo bash script automatically

   man sudo

   -S The -S (stdin) option causes sudo to read the password from
   the standard input instead of the terminal device. The
   password must be followed by a newline character.

   Used as a standard input pipe

   echo "password" |sudo -S

   This would avoid an interactive shell, so that the application in the script.

2. java call shell script

       public static String bashCommand(String command) {
           Process process = null;
           String stringBack = null;
           List<String> processList = new ArrayList<String>();
           try {
               process = Runtime.getRuntime().exec(command);
               BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
               String line = "";
               while ((line = input.readLine()) != null) {
                   processList.add(line);
               }
               input.close();
           } catch (IOException e) {
               e.printStackTrace();
           }
           for (String line : processList) {
               stringBack += line;
               stringBack +="\n";
           }
           return stringBack;
       }

   But I found a problem, that is, if the project packaged into a jar package if (item is a desktop software), resources within the jar package can not be directly referenced externally, for example: if a script on the resource under, obtained by getResoures path, then perform "bash <the script path>" can not run, because the script file is in a jar. I think the solution is to be executed when the script first by getClass (). GetClassLoader (). GetResource ( ) .OpenStream (); obtain input stream, and then create a file, the original file is written script to a new file (the file at this time is outside the jar package) through the stream, and then perform a new file, deleted after execution .

   And make things happen one: some command in a shell there is indeed a return value, but always with the above function returns null, but then I thought of awkward, is to write a shell script, the command returns the value assignment to a variable, then this variable echo:

   #!/bin/bash
   ip=$(ifconfig | grep "inet 192*")
   echo $ip