Getting rid of spaces in a returned string in bash

This is a follow-up from another thread here. https://shorturl.at/kyAu3

I'm getting SMMPv3 enigineID's from several thousand devices that may get replaced with new ones and any time due to break/fix. I have an input list of the devices. I need to get this result written to /etc/snmp/snmptrapd.conf when all is said and done.

createUser -e 800092C404534E2D353332303435383232 UserName SHA Authphrase AES passphrase

Here's what I'm doing

while IFS=, read -r myIP UserIn _
do
    UserName=''
   
    case $UserIn in
      EverNeXT)
          UserName="DeviceType_1"
          ;;
      UPS)
          UserName="DeviceType_2"
          ;;
      *)
          echo "$(date '+%Y-%m-%d %H:%M:%S') Exception! Missing or incorrect information in $DeviceList, look for $myIP or $UserIn" >> $myLog
          UserName="foobar"
    esac

Then I do an snmpget to the FQDN's from the above to get the engineID which is a hex string, with a space between every two values. I need to strip the spaces and write it to snmptrapd.conf

if test $snmpget_RC -eq 0
then
    set -- $(snmpget -v3 -l authPriv -u $UserName -a SHA -A Authphrase -x AES -X Passphrase $myIP SNMP-FRAMEWORK-MIB::snmpEngineID.0)
    shift 3
    IFS=""
    echo "Hex value for $myIP is $*"
    echo 'createUser -e' "$*" $UserName' SHA Authphrase AES Passphrase ' >>$snmpPath/$MyFile
else
    echo "$(date '+%Y-%m-%d %H:%M:%S') $myIP is not reachable" >> $myLog
    RC=0
fi

I got some greatly appreciated help in the other thread, but comments doesn't let me post this followup information and I'm not really answering my own question.

I do get one instance of the engineID written correctly, but the rest is garbage. Here's what the relevant part of my snmptrapd.conf looks like when done

createUser -e 800092C404534E2D353332303435383232 UserName SHA Authphrase AES passphrase
createUser -e SNMP-FRAMEWORK-MIB::snmpEngineID.0 = Hex-STRING: 80 00 92 C4 04 53 4E 2D 35 33 32 30 36 30 35 37
39  UserName SHA Authphrase AES Passphrase

The first line is perfect, the rest isn't usable. Is it because I'm using IFS twice? or something else? More importantly, how to I get it so all lines in snmptrapd.conf are like the first one?

Regards, Tom

You didn't give this context in your previous question. Yes, looping over this sequence causes trouble, because on the second iteration the IFS="" setting is in effect for the set -- $(snmpget ...) making it not split as you want.

However, you also didn't specify bash on your previous question. With bash the first solution I gave before -- read -d '' x x x hex < <(snmpget ...) then ${hex//[:space:]} -- is probably better. Or you can use this modified approach which doesn't change IFS:

   set -- $(snmpget ...) # unquoted, splits on default IFS including newline
   shift 3; hex=$* # rebuilt with spaces (but not newline)
   echo createuser -e ${hex// } ... # removes spaces in some shells including bash