termux-tasker | Termux add-on app for integration with Tasker | Hacking library

Latest version is v0.6.0. Check termux-app Installation for details before reading forward.
The Termux:Tasker plugin requires Termux app to run the actual commands. You need to install it and start it at least once and have it install the bootstrap files for the plugin to start working. The Termux prefix directory /data/data/com.termux/files/usr/ and Termux home directory /data/data/com.termux/files/home/ must also exist and must have read, write and execute permissions (0700) for the plugin to work. The $PREFIX/ is shortcut for the Termux prefix directory and can also be referred by the $PREFIX shell environment variable. The ~/ is a shortcut for the Termux home directory and can also be referred by the $HOME shell environment variable. Note that ~/ will not expand inside single or double quotes when running commands. Permissions and ownerships can be checked with the stat <path> command. For Termux:Tasker version >= 0.5, the plugin host app will need to be granted the com.termux.permission.RUN_COMMAND permission to run ANY plugin commands. This is a security measure to prevent any other apps from running commands in Termux context which do not have the required permission granted to them. This is also required for the RUN_COMMAND Intent intent. The Tasker app has requested the permission since v5.9.3, so you will need to update the app if you are using an older version. You can grant the permission using the Permissions activity in the App Info activity of your plugin host app. For Tasker you can grant it with: Android Settings -> Apps -> Tasker -> Permissions -> Additional permissions -> Run commands in Termux environment. If you do not grant the permission, you will likely get errors like receiver com.termux.tasker.FireReceiver requires permission com.termux.permission.RUN_COMMAND which we don't have when running the Termux:Tasker plugin action in Tasker. Note that, the %errmsg for missing permissions will not be set if you are using Tasker version < 5.11.1.beta and Continue Task After Error is enabled, only %err will be set to 1. You can open the plugin configuration screen to detect missing permissions of the plugin host. The ~/.termux/tasker/ directory stores the scripts that can be run with the plugin without setting allow-external-apps property to true if you do not want to use absolute paths. Open a non-root termux session and run the below command to create it and give it read, write and executable permissions (0700). The tasker directory must have read permission, otherwise the plugin will not be able to read the script files and give errors like No regular file found at path for any script name entered in the Executable field of plugin configuration. The tasker directory of the script must also have executable permissions for the script to be allowed to execute. Termux:Tasker version >= 0.5 also allows commands to be run outside the ~/.termux/tasker/ directory by setting absolute paths in the Executable field of the plugin configuration ONLY if allow-external-apps property is set to true in ~/.termux/termux.properties file. This is an added security measure. DO NOT set it to true if you have given a relatively untrusted app com.termux.permission.RUN_COMMAND permission, since it will be able to run arbitrary commands in termux or even root context (assuming termux has been granted root permissions) in the background without user intervention. The ~/.termux directory must have read permission, otherwise the plugin will not be able to read the property values. This is also required for the RUN_COMMAND Intent intent. For android >= 10 there are new restrictions that prevent activities from starting from the background. This prevents the background TermuxService from starting a terminal session in the foreground and running the commands until the user manually clicks Termux notification in the status bar dropdown notifications list. This only affects plugin commands that are to be executed in a terminal session and not the background ones. Termux version >= 0.100 requests the Draw Over Apps permission so that users can bypass this restriction so that commands can automatically start running without user intervention. You can grant Termux the Draw Over Apps permission from its App Info activity Android Settings -> Apps -> Termux -> Advanced -> Draw over other apps.
Automatic You can use the one-liner commands below to set the desired value. The commands will append the desired value using echo command to the file if the file doesn't exist or the property doesn't exist in the file, otherwise it will sed replace any existing values of the key with the desired value. To set allow-external-apps property to true.
Manual You can do it manually by running the below commands to open the nano text editor in the terminal. Then add/update a line allow-external-apps=true to set the property to true, and press Ctrl+o and then Enter to save and Ctrl+x to exit.