In /usr/bin/lft.db line 43:
PARSED=`getopt -o 'ACEFINRSTUVbehinpruvzd:s:m:M:a:c:t:l:H:L:q:D:' -l help -- "$@"`
       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
PARSED=$(getopt -o 'ACEFINRSTUVbehinpruvzd:s:m:M:a:c:t:l:H:L:q:D:' -l help -- "$@")


In /usr/bin/lft.db line 44:
[ $? != 0 ] && exit 2
  ^-- SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.


In /usr/bin/lft.db line 76:
	-[ieErCTUV])  warning $1; shift ;;
                              ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
	-[ieErCTUV])  warning "$1"; shift ;;


In /usr/bin/lft.db line 77:
	-[Mq])  warning $1; shift 2 ;;
                        ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
	-[Mq])  warning "$1"; shift 2 ;;


In /usr/bin/lft.db line 107:
opts="$opts -N $(($ahead * $queries))"
                  ^----^ SC2004: $/${} is unnecessary on arithmetic variables.
                           ^------^ SC2004: $/${} is unnecessary on arithmetic variables.


In /usr/bin/lft.db line 110:
timeout=`printf "%04d" $timeout`
        ^----------------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                       ^------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
timeout=$(printf "%04d" "$timeout")


In /usr/bin/lft.db line 116:
exec /usr/bin/traceroute.db $opts $host $length
                            ^---^ SC2086: Double quote to prevent globbing and word splitting.
                                  ^---^ SC2086: Double quote to prevent globbing and word splitting.
                                        ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
exec /usr/bin/traceroute.db "$opts" "$host" "$length"

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2004 -- $/${} is unnecessary on arithmeti...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...