In /usr/bin/pdf2dsc line 11: gs="`dirname \"$0\"`/$GS_EXECUTABLE" ^--------------^ SC2006: Use $(...) notation instead of legacy backticked `...`. Did you mean: gs="$(dirname \"$0\")/$GS_EXECUTABLE" In /usr/bin/pdf2dsc line 17: me=`basename $0` ^-----------^ SC2006: Use $(...) notation instead of legacy backticked `...`. ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: me=$(basename "$0") In /usr/bin/pdf2dsc line 20: >&2 echo usage: $me "pdffile [ dscfile ]" ^-^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: >&2 echo usage: "$me" "pdffile [ dscfile ]" In /usr/bin/pdf2dsc line 31: : ${dscfile:=`echo $pdffile | sed 's,\.[^/.]*,,'`.dsc} ^-- SC2223: This default assignment may cause DoS due to globbing. Quote it. ^-- SC2006: Use $(...) notation instead of legacy backticked `...`. ^------^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: : ${dscfile:=$(echo "$pdffile" | sed 's,\.[^/.]*,,').dsc} For more information: https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ... https://www.shellcheck.net/wiki/SC2223 -- This default assignment may cause... https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...