In /usr/bin/traceroute-nanog line 34: PARSED=`getopt 'adnruvAMOPQU$w:S:m:p:q:g:t:s:I:f:T:' "$@"` ^-- SC2006: Use $(...) notation instead of legacy backticked `...`. ^-- SC2016: Expressions don't expand in single quotes, use double quotes for that. Did you mean: PARSED=$(getopt 'adnruvAMOPQU$w:S:m:p:q:g:t:s:I:f:T:' "$@") In /usr/bin/traceroute-nanog line 35: [ $? != 0 ] && { ^-- SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?. In /usr/bin/traceroute-nanog line 61: -[aUOvQ]) warning $1; shift ;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: -[aUOvQ]) warning "$1"; shift ;; In /usr/bin/traceroute-nanog line 62: -T) warning $1; shift 2 ;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: -T) warning "$1"; shift 2 ;; In /usr/bin/traceroute-nanog line 75: exec /usr/bin/traceroute.db $opts $1 $2 ^---^ SC2086: Double quote to prevent globbing and word splitting. ^-- SC2086: Double quote to prevent globbing and word splitting. ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: exec /usr/bin/traceroute.db "$opts" "$1" "$2" For more information: https://www.shellcheck.net/wiki/SC2016 -- Expressions don't expand in singl... https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ... https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...