I spent an age looking into this very issue, and I modified my existing to add this function a few weeks back, just tidied the formatting up before posting.
Feel free, it seems to do the job for me.
apiUser=$4
apiPass=$5
apiURL=$6
ScriptName="append prefix here as needed - Check and Rename Machine Based On EA Value"
Check(){
/bin/echo
/bin/echo Current Computer Name = $macName
/bin/echo Computer Serial Number = $serial
/bin/echo Target Computer Name = $TargetComputerName
if [ "$preloadEntryB" != "" ]
then
/bin/echo Preload Inventory Entry for Serial Number $serial is $preloadEntryPresent
if [ "$preloadEntryID" != "" ]
then
/bin/echo Preload Inventory Entry ID Serial Number $serial is $preloadEntryID
if [ "$preloadEAentry" != "" ]
then
/bin/echo Preload Inventory EA Entry for Serial Number $serial is $preloadEAentryPresent
if [ "$preloadEAentryTCN" != "" ]
then
/bin/echo Preload Inventory EA '"'Target Computer Name'"' Entry for Serial Number $serial is $preloadEAentryTCNPresent
if [ "$preloadEAentryTCNValue" != "" ]
then
/bin/echo Preload Inventory EA '"'Target Computer Name'"' Entry for Serial Number $serial = $preloadEAentryTCNValue
else
/bin/echo Preload Inventory EA '"'Target Computer Name'"' Entry for Serial Number $serial is $preloadEAentryTCNValuePresent
fi
else
/bin/echo Preload Inventory EA '"'Target Computer Name'"' Entry for Serial Number $serial is $preloadEAentryTCNPresent
fi
else
/bin/echo Preload Inventory EA Entry for Serial Number $serial is $preloadEAentryPresent
fi
fi
fi
}
ScriptEnd(){
/bin/echo Ending Script '"'$ScriptName'"'
/bin/echo
/bin/echo -----------------------------------------------
/bin/echo
}