#!/bin/bash
#<pre><b>
# Script     : numtest
# Version    : 1.0
# Author     : Roland Rashleigh-Berry
# Date       : 09-Feb-2004
# Purpose    : Test a string for being an valid integer or decimal number
# SubScripts : none
# Notes      : A decimal number may start with a "." but must not end with one.
#              A negative sign (but not a plus sign) is allowed in front of a 
#              valid number. A zero value is regarded as a valid numeric.
#
#              The exit code will be 0 if numeric, 1 if null and 2 if 
#              non-numeric or more than one parameter. Test for the return code
#              after calling this utility by checking the value of $? after the
#              call. See usage notes.
#
# Usage      : numtest 12a3.45 ; echo $?
#===============================================================================
# PARAMETERS:
#-pos- -------------------------------description-------------------------------
#  1   string to test for being a valid number
#===============================================================================
# AMENDMENT HISTORY:
# init --date-- mod-id ----------------------description------------------------
# 
#===============================================================================
# This is public domain software. No guarantee as to suitability or accuracy is
# given or implied. User uses this code entirely at their own risk.
#===============================================================================

if [ $# -lt 1 ] ; then 
  exit 1
elif [ $# -gt 1 ] ; then
  exit 2
fi

res=$(echo ${1} | egrep '^-?[0-9]*[0-9.]?[0-9]+$')

if [ -n "$res" ] ; then
  exit 0
else
  exit 2
fi