find a way to track the most recent version of shiny server and subsequently update system command about ramazon HOT 4 CLOSED

#XML is needed for this next chunk:
#Here we parse the xml of download3.rstudio.org/
#Using the rootsize we can extract the last entry which is the latest version of shiny server
if(!require(XML)){
  install.packages("XML")
  library(XML)
}
xml.url <- 'http://download3.rstudio.org/'
xmlParsed <- xmlParse(xml.url)
rootnode <- xmlRoot(xmlParsed)
rootsize <- xmlSize(rootnode)
latest_shiny_path <- xmlValue(rootnode[[rootsize]][[1]])
shiny_version <- unlist(strsplit(latest_shiny_path,'/'))[3]

# install latest Shiny server version
command <- c("\necho 'R installed'")
command <- append(command,"sudo apt-get install -y gdebi-core")
command <- append(command,paste0("wget https://download3.rstudio.org/",latest_shiny_path))
command <- append(command,paste0("sudo gdebi --non-interactive ",shiny_version))

    Imports: 
        XML 

    xml.url <- 'http://download3.rstudio.org/' 
    xmlParsed <- XML::xmlParse(xml.url) 
    rootnode <- XML::xmlRoot(xmlParsed) 
    rootsize <- XML::xmlSize(rootnode) 
    latest_shiny_path <- XML::xmlValue(rootnode[[rootsize]][[1]]) 
    shiny_version <- unlist(strsplit(latest_shiny_path,'/'))[3]