#!/bin/ksh
#
# version_chk
# Korn shell function
# Compares two numeric strings to determine if one is greater than, less than,
# or equal to the other. Does not handle non-numeric version strings.
#
AUTHOR="Mike Arnold <mike at razorsedge dot org>"
VERSION="200402030242"
#
# $Id: version_chk,v 1.3 2004/02/03 11:41:33 marnold Exp $


# Function to compare a version string and return =(0), >(1), or <(2).
version_chk () {
  CURRENT=$1
  BASELINE=$2

  IFSTMP="$IFS" ; IFS="."

  set $CURRENT
  # Think SCCS
  C_RELEASE=${1:-0}
  C_LEVEL=${2:-0}
  C_BRANCH=${3:-0}
  C_SEQUENCE=${4:-0}
  if [ $DEBUG ]; then
    echo C_RELEASE=$C_RELEASE
    echo C_LEVEL=$C_LEVEL
    echo C_BRANCH=$C_BRANCH
    echo C_SEQUENCE=$C_SEQUENCE
  fi

  set $BASELINE
  # Think SCCS
  B_RELEASE=${1:-0}
  B_LEVEL=${2:-0}
  B_BRANCH=${3:-0}
  B_SEQUENCE=${4:-0}
  if [ $DEBUG ]; then
    echo B_RELEASE=$B_RELEASE
    echo B_LEVEL=$B_LEVEL
    echo B_BRANCH=$B_BRANCH
    echo B_SEQUENCE=$B_SEQUENCE
  fi

  IFS="$IFSTMP"

  # return =(0), >(1), or <(2).
  if [[ "$C_RELEASE" -eq "$B_RELEASE" && \
        "$C_LEVEL" -eq "$B_LEVEL" && \
        "$C_BRANCH" -eq "$B_BRANCH" && \
        "$C_SEQUENCE" -eq "$B_SEQUENCE" ]]; then
    return 0
  fi
  if [[ "$C_RELEASE" -gt "$B_RELEASE" ]]; then
    return 1
  elif [[ "$C_LEVEL" -gt "$B_LEVEL" ]]; then
    return 1
  elif [[ "$C_BRANCH" -gt "$B_BRANCH" ]]; then
    return 1
  elif [[ "$C_SEQUENCE" -gt "$B_SEQUENCE" ]]; then
    return 1
  fi
  if [[ "$C_RELEASE" -lt "$B_RELEASE" ]]; then
    return 2
  elif [[ "$C_LEVEL" -lt "$B_LEVEL" ]]; then
    return 2
  elif [[ "$C_BRANCH" -lt "$B_BRANCH" ]]; then
    return 2
  elif [[ "$C_SEQUENCE" -lt "$B_SEQUENCE" ]]; then
    return 2
  fi
  return 5
}

# If the variable DEBUG is set, then turn on tracing.
# http://www.research.att.com/lists/ast-users/2003/05/msg00009.html
if [ $DEBUG ]; then
  # This will turn on the ksh xtrace option for mainline code
  set -x

  # This will turn on the ksh xtrace option for all functions
  typeset +f |
  while read F junk
  do
    typeset -ft $F
  done
  unset F junk
fi

version_chk $1 $2
RETURN=$?	# return =(0), >(1), or <(2).
if [[ $RETURN -eq 0 ]]; then RESULT="equal to"
elif [[ $RETURN -eq 1 ]]; then RESULT="greater than"
elif [[ $RETURN -eq 2 ]]; then RESULT="less than"
fi
echo "$1 is $RESULT $2"