Can I update the adb shell's environment variables? I wanted to update the PATH environment variable permanently in the adb shell. I guessed the shell was mksh for I've found /system/bin/sh pointing to /system/bin/mksh. Then I tried


Making a new file /data/.mkshrc and adding the PATH definition into it.
Copy the above file into /.
Copy to /root.


But all attempts failed.
By default stock Android mksh uses this config file: /system/etc/mkshrc