In /usr/bin/xpdf line 28: cmd="$cmd $1 "$2"" && shift ;; ^-- SC2027: The surrounding quotes actually unquote this. Remove or escape them. In /usr/bin/xpdf line 44: test -f "$1" && file="$1" && shift && pages="$@" && break || ^--^ SC2124: Assigning an array to a string! Assign as array, or use * instead of @ to concatenate. ^-- SC2015: Note that A && B || C is not if-then-else. C may run when A is true. In /usr/bin/xpdf line 58: printf "%s\n" "$many" | while read -r file; do ^--^ SC2030: Modification of file is local (to subshell caused by pipeline). In /usr/bin/xpdf line 62: tmp=$(tempfile -s .pdf) ^------^ SC2186: tempfile is deprecated. Use mktemp instead. In /usr/bin/xpdf line 63: case "$file" in ^---^ SC2031: file was modified in a subshell. That change might be lost. In /usr/bin/xpdf line 64: *.gz|*.Z|*.xz|*.bz2) test "$title" != "" || title="Xpdf: $file";; ^---^ SC2031: file was modified in a subshell. That change might be lost. In /usr/bin/xpdf line 66: case "$file" in ^---^ SC2031: file was modified in a subshell. That change might be lost. In /usr/bin/xpdf line 67: *.gz|*.Z) zcat "$file" > "$tmp" && exec 3< "$tmp" && file="/dev/fd/3";; ^---^ SC2031: file was modified in a subshell. That change might be lost. In /usr/bin/xpdf line 74: exec $cmd || true ^--^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: exec "$cmd" || true In /usr/bin/xpdf line 76: exec $cmd "$file" $pages || true ^--^ SC2086: Double quote to prevent globbing and word splitting. ^----^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: exec "$cmd" "$file" "$pages" || true In /usr/bin/xpdf line 78: exec $cmd -title "$title" "$file" $pages || true ^--^ SC2086: Double quote to prevent globbing and word splitting. ^----^ SC2086: Double quote to prevent globbing and word splitting. Did you mean: exec "$cmd" -title "$title" "$file" "$pages" || true For more information: https://www.shellcheck.net/wiki/SC2027 -- The surrounding quotes actually u... https://www.shellcheck.net/wiki/SC2124 -- Assigning an array to a string! A... https://www.shellcheck.net/wiki/SC2186 -- tempfile is deprecated. Use mktem...