phon num gen

    #!/bin/bash
    # Phone list generator
    # 2013-01-13 ax0n@h-i-r.net
    if [ -z "$2" ]
    then
      echo "$0 start end"
      echo "number format: nnn-nnn-nnnn"
      echo "Ex: $0 913-259-0000 913-259-9999"
      exit 1
    fi
    n=`echo $1 | tr -d -`
    e=`echo $2 | tr -d -`
    while [ $n -lt $e ]
    do
     n=`expr $n + 1`
     echo $n | sed 's/\(...\)\(...\)\(....\)/\1-\2-\3/'
    done