In /usr/bin/what-patch line 58: files=`lsdiff -z ../$(dpkg-parsechangelog -SSource)_$(dpkg-parsechangelog -SVersion).diff.gz 2>/dev/null | grep -v 'debian/'` ^-- SC2006: Use $(...) notation instead of legacy backticked `...`. ^-----------------------------^ SC2046: Quote this to prevent word splitting. ^-- SC2046: Quote this to prevent word splitting. Did you mean: files=$(lsdiff -z ../$(dpkg-parsechangelog -SSource)_$(dpkg-parsechangelog -SVersion).diff.gz 2>/dev/null | grep -v 'debian/') In /usr/bin/what-patch line 69: if fgrep -q quilt debian/source/format 2>/dev/null; then ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/what-patch line 78: for filename in $(echo "debian/rules"; grep ^include debian/rules | fgrep -v '$(' | awk '{print $2}') ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. ^--^ SC2016: Expressions don't expand in single quotes, use double quotes for that. In /usr/bin/what-patch line 80: fgrep patchsys.mk "$filename" | grep -q -v "^#" && { ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/what-patch line 87: fgrep quilt "$filename" | grep -q -v "^#" && { echo "quilt"; exit 0; } ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/what-patch line 88: fgrep dbs-build.mk "$filename" | grep -q -v "^#" && { ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/what-patch line 95: fgrep dpatch "$filename" | grep -q -v "^#" && { ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. In /usr/bin/what-patch line 102: fgrep '*.diff' "$filename" | grep -q -v "^#" && { ^---^ SC2197: fgrep is non-standard and deprecated. Use grep -F instead. For more information: https://www.shellcheck.net/wiki/SC2046 -- Quote this to prevent word splitt... https://www.shellcheck.net/wiki/SC2016 -- Expressions don't expand in singl... https://www.shellcheck.net/wiki/SC2197 -- fgrep is non-standard and depreca...