:local content $1
    :local cleanedContent ""
    :local start 0
    :local end 1

    # Loop through each character and remove '\r'
    :for i from=0 to=([:len $content]) step=1 do={
        :local char [:pick $content $start $end ]
        :local check [:find $char "\r"]
               :if ($check < 0 ) do={
            :set cleanedContent ($cleanedContent . $char)
        }
        :set start ($start + 1)
        :set end ($end +1)
}

:return $cleanedContent

#Import the function from system scripts with name dos2unix
:local dos2unix [:parse [/system script get dos2unix source]]

#Load the content of the file, call the function and save the cleaned results to the file.
:local content [/file get test.txt contents]
:local cleanedContent [$dos2unix $content]
/file set test.txt contents=$cleanedContent

        :local check [:find $char "\r"]
               :if ($check < 0 ) do={
           :set cleanedContent ($cleanedContent . $char)
        }

       :if ($char != "\r") do={:set cleanedContent "$cleanedContent$char"}

:put [:convert from=raw to=hex [:tolf "0\r\n0\r\n"]]  

:put [:convert from=raw to=hex [:tocrlf "0\n0\n"]] 

:put [:convert from=raw to=hex "0\r\n0\r\n"]          
# 300d0a300d0a
:put [:convert from=raw to=hex "0\n0\n"]      
# 300a300a