examples/functions/sort-pos-params

   1 # Sort the positional paramters.
   2 # Make sure the positional parameters are passed as arguments to the function.
   3 # If -u is the first arg, remove duplicate array members.
   4 sort_posparams()
   5 {
   6         local -a R
   7         local u
   8
   9         case "$1" in
  10         -u)     u=-u ; shift ;;
  11         esac
  12
  13         # if you want the case of no positional parameters to return success,
  14         # remove the error message and return 0
  15         if [ $# -eq 0 ]; then
  16                 echo "$FUNCNAME: argument expected" >&2
  17                 return 1
  18         fi
  19
  20         # make R a copy of the positional parameters
  21         R=( "${@}" )
  22
  23         # sort R.
  24         R=( $( printf "%s\n" "${R[@]}" | sort $u) )
  25
  26         printf "%s\n" "${R[@]}"
  27         return 0
  28 }
  29
  30 # will print everything on separate lines
  31 set -- 3 1 4 1 5 9 2 6 5 3 2
  32 sort_posparams "$@"
  33
  34 # sets without preserving quoted parameters
  35 set -- $( sort_posparams "$@" )
  36 echo "$@"
  37 echo $#
  38
  39 # sets preserving quoted parameters, beware pos params with embedded newlines
  40 set -- 'a b' 'a c' 'x z'
  41
  42 oifs=$IFS
  43 IFS=$'\n'
  44 set -- $( sort_posparams "$@" )
  45 IFS="$oifs"
  46
  47 echo "$@"
  48 echo $#
  49
  50 sort_posparams