[lint] FIX SC2086: use double quotes on vars

pdf-optimize

@@ -78,7 +78,7 @@ function arg_parse
 
 function yes_or_no
 {
-	read -p "$* [y/N]: " ans
+	read -pr "$* [y/N]: " ans
 	case "$ans" in
 		[yY] | [yY]es )     return 0;;
 		* )                 echo "Aborting"; return 1;;
@@ -103,8 +103,8 @@ ${bold}$output_path${normal}."
 		   -dNOPAUSE \
 		   -dQUIET \
 		   -dBATCH \
-		   -sOutputFile=$output_path \
-		   $input_path
+		   -sOutputFile="$output_path" \
+		   "$input_path"
 	else
 		echo "input_path=$input_path";
 		echo "output_path=$output_path";
@@ -117,8 +117,8 @@ ${bold}$output_path${normal}."
 		   -dPDFSETTINGS=/prepress \
 		   -dNOPAUSE \
 		   -dBATCH \
-		   -sOutputFile=$output_path \
-		   $input_path 
+		   -sOutputFile="$output_path" \
+		   "$input_path" 
 	fi
 	
 	# catching errors
@@ -136,11 +136,11 @@ ${bold}$output_path${normal}."
 
 function compute_compression
 {
-	input_size=`du "$input_path" | cut -f1`
-	output_size=`du "$output_path" | cut -f1`
-	percentage=`echo "scale=1;$output_size / $input_size * 100" | bc -l`
-	input_size_h=`du -h "$input_path" | cut -f1`
-	output_size_h=`du -h "$output_path" | cut -f1`
+	input_size=$(du "$input_path" | cut -f1)
+	output_size=$(du "$output_path" | cut -f1)
+	percentage=$(echo "scale=1;$output_size / $input_size * 100" | bc -l)
+	input_size_h=$(du -h "$input_path" | cut -f1)
+	output_size_h=$(du -h "$output_path" | cut -f1)
 
 	echo "Size reduced from ${bold}$input_size_h${normal} to \
 ${bold}$output_size_h${normal} [$percentage %]"