editing a value in the file p2p_supplicant.conf which is located on /root/data/misc/wifi/p2p_supplicant.conf

Question

I am trying to develop a function for editing a value in the root file p2p_supplicant.conf which is located on /root/data/misc/wifi/p2p_supplicant.conf

The toast messa

Answer 1

Basically, you are reading the file, changing the channel then rewriting the whole file. I am looking for a solution where you read the file first, edit it then write it back. Once I resolve that issue I will edit my answer here. Note before testing it, make a backup file for your wpa_supplicant.conf file in case errors happen.

Step 1: reading the file = check this solution: Executing a Process in Android to read a file

Step 2: looping over the String containing the text of the file and changing the operating channel and saving the the whole text in String text

Step 3: writing text into the the file

    Process p; 
            try { 
               // Preform su to get root privileges
               p = Runtime.getRuntime().exec("su"); 

               // Attempt to write a file to a root-only 
               DataOutputStream os = new DataOutputStream(p.getOutputStream()); 
               os.writeBytes("echo \""+text+"\" > /data/misc/wifi/p2p_supplicant.conf\n");
               // Close the terminal
               os.writeBytes("exit\n"); 
               os.flush(); 
               try { 
                  p.waitFor(); 
                       if (p.exitValue() != 255) { 
                          // TODO Code to run on success
                       } 
                       else { 
                           // TODO Code to run on unsuccessful
                       } 
               } catch (InterruptedException e) { 
                  // TODO Code to run in interrupted exception
               } 
            } catch (IOException e) { 
               // TODO Code to run in input/output exception
            }