使用java runtime exec运行连续的Commands Linux

Question

我需要使用java代码运行两个命令linux,如下所示:

 Runtime rt = Runtime.getRuntime();


            Process  pr=rt.exec("su - test");
            String line=null;
            BufferedReader input = new BufferedReader(new InputStreamReader(pr.getInputStream()));

            while((line=input.readLine()) != null) {

                System.out.println(line);
            }
           pr = rt.exec("whoami");
             input = new BufferedReader(new InputStreamReader(pr.getInputStream()));

             line=null;

            while((line=input.readLine()) != null) {
                 System.out.println(line);
            }               
            int exitVal = pr.waitFor();
            System.out.println("Exited with error code "+exitVal);              
        } catch(Exception e) {
            System.out.println(e.toString());
            e.printStackTrace();
        }

问题是第二个命令("whoami")的输出不显示第一个命令("su - test")上使用的当前用户!! 请问这个代码有什么问题吗？

Answer 1

在一般情况下,您需要在shell中运行命令.像这样的东西:

    Process  pr = rt.exec(new String[]{"/bin/sh", "-c", "cd /tmp ; ls"});

但在这种情况下,这不会起作用,因为su它本身正在创建一个交互式子shell.你可以这样做:

    Process  pr = rt.exec(new String[]{"su", "-c", "whoami", "-", "test"});

要么

    Process  pr = rt.exec(new String[]{"su", "test", "-c", "whoami"});

另一种选择是使用sudo而不是su; 例如

    Process  pr = rt.exec(new String[]{"sudo", "-u", "test", "whoami"});

注意:虽然以上都不需exec要这样做,但最好将"命令行"组装为字符串数组,而不是进行"解析".(问题是execs splitter不理解shell引用.)