Android: Requesting root access in your app
package com.certusnet.videomonitor; import java.util.List; import java.io.IOException; import java.io.BufferedReader; import java.io.DataOutputStream; import java.io.InputStreamReader; import android.util.Log; /** * ShellUtils * <ul> * <strong>Check root</strong> * <li>{@link ShellUtils#checkRootPermission()}</li> * </ul> * <ul> * <strong>Execte command</strong> * <li>{@link ShellUtils#execCommand(String, boolean)}</li> * <li>{@link ShellUtils#execCommand(String, boolean, boolean)}</li> * <li>{@link ShellUtils#execCommand(List, boolean)}</li> * <li>{@link ShellUtils#execCommand(List, boolean, boolean)}</li> * <li>{@link ShellUtils#execCommand(String[], boolean)}</li> * <li>{@link ShellUtils#execCommand(String[], boolean, boolean)}</li> * </ul> * * @author <a href="http://www.trinea.cn" target="_blank">Trinea</a> 2013-5-16 */ public class ShellUtils { public static final String COMMAND_SU = "su"; public static final String COMMAND_SH = "sh"; public static final String COMMAND_EXIT = "exit\n"; public static final String COMMAND_LINE_END = "\n"; private ShellUtils() { throw new AssertionError(); } /** * check whether has root permission * * @return */ public static boolean checkRootPermission() { return execCommand("echo root", true, false).result == 0; } /** * execute shell command, default return result msg * * @param command * command * @param isRoot * whether need to run with root * @return * @see ShellUtils#execCommand(String[], boolean, boolean) */ public static CommandResult execCommand(String command, boolean isRoot) { return execCommand(new String[] { command }, isRoot, true); } /** * execute shell commands, default return result msg * * @param commands * command list * @param isRoot * whether need to run with root * @return * @see ShellUtils#execCommand(String[], boolean, boolean) */ public static CommandResult execCommand(List<String> commands, boolean isRoot) { return execCommand(commands == null ? null : commands.toArray(new String[] {}), isRoot, true); } /** * execute shell commands, default return result msg * * @param commands * command array * @param isRoot * whether need to run with root * @return * @see ShellUtils#execCommand(String[], boolean, boolean) */ public static CommandResult execCommand(String[] commands, boolean isRoot) { return execCommand(commands, isRoot, true); } /** * execute shell command * * @param command * command * @param isRoot * whether need to run with root * @param isNeedResultMsg * whether need result msg * @return * @see ShellUtils#execCommand(String[], boolean, boolean) */ public static CommandResult execCommand(String command, boolean isRoot, boolean isNeedResultMsg) { return execCommand(new String[] { command }, isRoot, isNeedResultMsg); } /** * execute shell commands * * @param commands * command list * @param isRoot * whether need to run with root * @param isNeedResultMsg * whether need result msg * @return * @see ShellUtils#execCommand(String[], boolean, boolean) */ public static CommandResult execCommand(List<String> commands, boolean isRoot, boolean isNeedResultMsg) { return execCommand(commands == null ? null : commands.toArray(new String[] {}), isRoot, isNeedResultMsg); } /** * execute shell commands * * @param commands * command array * @param isRoot * whether need to run with root * @param isNeedResultMsg * whether need result msg * @return <ul> * <li>if isNeedResultMsg is false, {@link CommandResult#successMsg} * is null and {@link CommandResult#errorMsg} is null.</li> * <li>if {@link CommandResult#result} is -1, there maybe some * excepiton.</li> * </ul> */ public static CommandResult execCommand(String[] commands, boolean isRoot, boolean isNeedResultMsg) { int result = -1; if (commands == null || commands.length == 0) { return new CommandResult(result, null, null); } Process process = null; BufferedReader successResult = null; BufferedReader errorResult = null; StringBuilder successMsg = null; StringBuilder errorMsg = null; DataOutputStream os = null; try { process = Runtime.getRuntime().exec(isRoot ? COMMAND_SU : COMMAND_SH); os = new DataOutputStream(process.getOutputStream()); for (String command : commands) { if (command == null) { continue; } // donnot use os.writeBytes(commmand), avoid chinese charset // error Log.w("execCommand:", command); os.write(command.getBytes()); os.writeBytes(COMMAND_LINE_END); os.flush(); } os.writeBytes(COMMAND_EXIT); os.flush(); result = process.waitFor(); // get command result if (isNeedResultMsg) { successMsg = new StringBuilder(); errorMsg = new StringBuilder(); successResult = new BufferedReader(new InputStreamReader(process.getInputStream())); errorResult = new BufferedReader(new InputStreamReader(process.getErrorStream())); String s; while ((s = successResult.readLine()) != null) { successMsg.append(s); } while ((s = errorResult.readLine()) != null) { errorMsg.append(s); } } } catch (IOException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } finally { try { if (os != null) { os.close(); } if (successResult != null) { successResult.close(); } if (errorResult != null) { errorResult.close(); } } catch (IOException e) { e.printStackTrace(); } if (process != null) { process.destroy(); } } return new CommandResult(result, successMsg == null ? null : successMsg.toString(), errorMsg == null ? null : errorMsg.toString()); } /** * result of command * <ul> * <li>{@link CommandResult#result} means result of command, 0 means normal, * else means error, same to excute in linux shell</li> * <li>{@link CommandResult#successMsg} means success message of command * result</li> * <li>{@link CommandResult#errorMsg} means error message of command result</li> * </ul> * * @author <a href="http://www.trinea.cn" target="_blank">Trinea</a> * 2013-5-16 */ public static class CommandResult { /** result of command **/ public int result; /** success message of command result **/ public String successMsg; /** error message of command result **/ public String errorMsg; public CommandResult(int result) { this.result = result; } public CommandResult(int result, String successMsg, String errorMsg) { this.result = result; this.successMsg = successMsg; this.errorMsg = errorMsg; } } }
调用，root权限启动mt_hls：
String filePath = getFilesDir().getAbsolutePath() + "/mt_hls"; CommandResult commandResult = ShellUtils.execCommand(new String[] { "cd /data/data/com.certusnet.videomonitor/files \n", "ulimit -c unlimited \n", "chown root " + filePath + " \n", "chmod 777 " + filePath }, true, false); //CommandResult commandResult = ShellUtils.execCommand(new String[] { "cd /data/data/com.certusnet.videomonitor/files \n", "ulimit -c unlimited \n", "chown root " + filePath + " \n", "chmod 777 " + filePath + " \n", filePath + " -p any -c -f -d" }, true, false); Log.d("initMonitorProcess", "mawei---" + commandResult.errorMsg + commandResult.result + commandResult.successMsg);
system root权限启动mt_hls：
int ret = system("su -c \"/data/data/com.certusnet.videomonitor/files/mt_hls -c -f -p any -d\"");
注：非root权限的进程，即当前进程无法获取ROOT权限，只能su赋予新独立进程root权限。jni层若果需要root权限，没有办法直接调用。
ioctl 操作驱动文件不需要root权限，但驱动文件必须有可操作权限。
参考：
http://stackoverflow.com/questions/6983156/android-ioctl-root-permissions-and-usage
http://www.stealthcopter.com/blog/2010/01/android-requesting-root-access-in-your-app/
