android code to move file into system?

Question

Im a galaxy s6 user here, I found out that the switch recent app button (the one on the left of the home button) quite annoying while playing game like vainglory because I misclicked it quite often. After doing some research I found out that it is possible to comment out the key 254 of generic.kl under system/usr/keylayout, then i come out with an idea of creating a new generic.kl which commented out the key 254, then with a click of button on my app it will move the file with the commented key to system/usr/keylayout to replace the old way, vice versa, I will make a restore button there to restore it will the original generic.kl when I wan the recent app switch to start working again. So my question here is what would be the code to move a file to system and replace it? I do have some basic android programming knowledge and my phone is rooted.

Thanks in advance.

Answer 1

Use the code below to copy to system. Requires root access.

void copyToSystem() {

    try {
        Process proc = Runtime.getRuntime().exec(
            new String[]{
                "su", "-c", 
                "mount -o rw,remount /system ;"
              + " cp -f /storage/sdcard0/MyFolder/MyKeyLayout.kl /system/usr/keylayout/ ;"
              + " mount -o ro,remount /system"});
        proc.waitFor();
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

You need to import java.lang.Process and not android.os.Process

Note: cp -f ensures that the file is replaced if already existing.