In /usr/bin/bookman line 75: (n) post=cat;; ^--^ SC2209: Use var=$(command) to assign output (or quote to assign string). In /usr/bin/bookman line 86: shift $(($OPTIND - 1)) ^-----^ SC2004: $/${} is unnecessary on arithmetic variables. In /usr/bin/bookman line 111: [ $1 ] || set -- $(while read REPLY; do echo "$REPLY"; done) ^-- SC2086: Double quote to prevent globbing and word splitting. ^-- SC2046: Quote this to prevent word splitting. ^--^ SC2162: read without -r will mangle backslashes. Did you mean: [ "$1" ] || set -- $(while read REPLY; do echo "$REPLY"; done) In /usr/bin/bookman line 113: [ $outfile ] && post="$post >$outfile" ^------^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: [ "$outfile" ] && post="$post >$outfile" In /usr/bin/bookman line 120: [ -f "$cover" ] && cat "$cover" || { ^-- SC2015: Note that A && B || C is not if-then-else. C may run when A is true. In /usr/bin/bookman line 132: (*.Z|*.gz) zcat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*.Z|*.gz) zcat "$f";; In /usr/bin/bookman line 133: (*.bz2) bzcat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*.bz2) bzcat "$f";; In /usr/bin/bookman line 134: (*) cat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*) cat "$f";; In /usr/bin/bookman line 161: (*.Z|*.gz) zcat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*.Z|*.gz) zcat "$f";; In /usr/bin/bookman line 162: (*.bz2) bzcat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*.bz2) bzcat "$f";; In /usr/bin/bookman line 163: (*) cat $f;; ^-- SC2086: Double quote to prevent globbing and word splitting. Did you mean: (*) cat "$f";; In /usr/bin/bookman line 167: } | eval $post ^---^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: } | eval "$post" For more information: https://www.shellcheck.net/wiki/SC2046 -- Quote this to prevent word splitt... https://www.shellcheck.net/wiki/SC2209 -- Use var=$(command) to assign outp... https://www.shellcheck.net/wiki/SC2015 -- Note that A && B || C is not if-t...