Using a scripted input's passAuth token for CLI access from the scripted input

There isn't a CLI argument to do that. You would likely be better served by going through the REST API if possible.

When you run a splunk CLI search, it will look in ~/.splunk for an existing authToken, and prompts you for credentials if a valid authToken is not found. Typically that file is written when you run splunk login.

There's nothing to prevent you from writing that file out yourself before calling the CLI, but give careful consideration to the implications of doing so. First, any user who could read that directory could use those credentials (which is already true). Second, if you also run CLI commands directly as root (or splunk's service account), either the interactive user or the scripted input could get the wrong credentials.

If you absolutely must call CLI commands directly, there's a workaround. Use mktemp to create a temporary directory, and make sure the permissions are restricted. Write the authToken to $TMPDIR/.splunk/authToken_<hostname>_<portnum>. Then, set the $HOME environment variable to your $TMPDIR before calling the CLI command(s). Once you're done, delete the authToken and the temporary directory.