float.sh

#!/bin/bash

# > float.sh <
# Support for floating point math in bash.

# The original code appears on linuxjournal.com, July 30, 2008:
# http://www.linuxjournal.com/content/floating-point-math-bash

# These were written by Mitch Frazier (I think) and are covered by the GNU Public License, version 2.


# Default scale used by bc.
float_scale=2

# Evaluate a floating point number expression.
function float_eval () {
  local stat=0
  local result=0.0
  if [[ $# -gt 0 ]]; then
    result=$(echo "scale=$float_scale; $*" | bc -q 2>/dev/null)
    stat=$?
    if [[ $stat -eq 0  &&  -z "$result" ]]; then
      stat=1;
    fi
  fi
  echo $result
  return $stat
}

# Evaluate a floating point number conditional expression.
function float_cond () {
  local cond=0
  if [[ $# -gt 0 ]]; then
    cond=$(echo "$*" | bc -q 2>/dev/null)
    if [[ -z "$cond" ]];
      then cond=0;
    fi
    if [[ "$cond" != 0  &&  "$cond" != 1 ]]; then
      cond=0;
    fi
  fi
  local stat=$((cond == 0))
  return $stat
}