UNIX for Dummies Questions & Answers

#!/bin/ksh
# input versionstring1   versionstring2  example: 10.10.1  10.8.3
# returns 0 if string1 = string2  
#          <0 if string1 < string2 
#           >0  if string1 > string2
# this assumes xx.xx.xx for version number
vercmp()
{
     IFS=.
     echo "$1"  | read a1 b1 c1
     echo "$2"  | read a2 b2 c2
     IFS=" "
     r1=$((a1 - a2))
     r2=$((b1 - b2))
     r3=$((c1 - c2))
     tot=$((r1 + r2 + r3))
     if [ $tot -eq 0 ] ; then
         print 0
         return 0
     fi
     if [[ $r1 -gt 0 || $r2 -gt 0 || $r3 -gt 0 ]] ; then  # changed
         print 1
         return 0
     fi
     retval="-1"        # changed
     echo  "$retval"  # changed

}

#usage:
if [ $(vercmp 10.10.1 10.2.4) -gt -1 ] ; then
       echo "version okay"
else
       echo "version too old"
fi