reem003.sh

#!/bin/bash

reem003(){
  local input1=$1
  local output=$2

  rm -f $output
  cat $input1 | while read line
  do
    local k=`echo "$line" | sed -e "s/[<>-][0-9\.]\+/-99999.9/g"`
    echo $k >> $output
  done
}

reem003 tameshi.txt output.txt

次の1行だけでできる！

sed -e "s/[<>-][0-9.]+/-99999.9/g" tameshi.txt > output.txt