There are a few environment variables that you need to consider when writing scripts because they will be helpful:
SCRIPT_PATH: This returns the absolute path of the running script
SCRIPT_NAME: This returns the running script name
SCRIPT_TYPE: This returns "prerule", "hostrule", "portrule", or "postrule"
SCRIPT_NAME environment variable instead of hardcoding the name of your script. This way, you won't need to update the script if you end up changing its name. For example, you could use it to read script arguments as follows:
local arg1 = stdnse.get_script_args(SCRIPT_NAME..".arg1")
stdnse library will be explored later in this chapter. This library contains the
get_script_args() function that can be used ...