## Extract Function
extract() {
  if [ ! -f "$1" ];
  then
   printf '"%s" is not a valid file.' "$1"
   exit 1
  fi

  case $1 in                                         
   *.tar.bz2)  tar xjf "$1"    ;;
   *.tar.gz)   tar xzf "$1"    ;;
   *.bz2)      bunzip2 "$1"    ;;
   *.rar)      unrar x "$1"    ;;
   *.gz)       gunzip "$1"     ;;
   *.tar)      tar xf "$1"     ;;
   *.tbz2)     tar xjf "$1"    ;;
   *.tgz)      tar xzf "$1"    ;;
   *.zip)      unzip "$1"      ;;
   *.Z)        uncompress "$1" ;;
   *.7z)       7z x "$1"       ;;
   *.deb)      ar x "$1"       ;;
   *.tar.xz)   tar xf "$1"     ;;
   *)          printf 'cannot extract "%s" with extract()' "$1" ;;
   esac                                              
 }