diff --git a/util/fp-finder/spell.sh b/util/fp-finder/spell.sh
old mode 100644
new mode 100755
index 77631d80c..bc51ac1c9
--- a/util/fp-finder/spell.sh
+++ b/util/fp-finder/spell.sh
@@ -1,20 +1,83 @@
 #!/bin/bash
 
-SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+if ! command -v spell > /dev/null 2>&1; then
+    echo "This program requires spell to be installed. Aborting"
+    exit 1
+fi
 
-RULES_DIR="${SCRIPT_DIR}/../../rules/"
+check() {
+    local datafile="${1}"
+    local datafile_name="${datafile##*/}"
 
-for datafile in "$RULES_DIR"*.data; do
-    DATAFILE_NAME=${datafile##*/}
-    
-    echo "-> checking ${DATAFILE_NAME}"
+    if ! ${MACHINE_READABLE}; then
+        echo "-> checking ${datafile_name}"
+    fi
 
     for word in $(grep -E '^[a-z]+$' "${datafile}" | uniq | sort); do
         IS_NOT_ENGLISH=$(echo "${word}" | spell | wc -l)
         if [ "${IS_NOT_ENGLISH}" -lt 1 ]; then
-            echo "   \`- found English word: ${word}"
+            if ! ${MACHINE_READABLE}; then
+                printf "   \`- found English word: "
+            fi
+            echo "${word}"
         fi
     done
 
-    echo ""
+    if ! ${MACHINE_READABLE}; then
+        echo ""
+    fi
+}
+
+usage() {
+    cat <<EOF
+usage: spell.sh [-mh] [file]
+    Finds English words in files that contain word lists.
+
+    The optional file argument is the path to a file you want to check. If omitted,
+    all files with the .data suffix in the rules directory will be searched.
+
+    -h, --help      Show this message and exit
+    -m, --machine   Print machine readable output
+EOF
+}
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+
+RULES_DIR="${SCRIPT_DIR}/../../rules/"
+
+MACHINE_READABLE=false
+
+POSITIONAL_ARGS=()
+while [[ $# -gt 0 ]]; do
+    # shellcheck disable=SC2221,SC2222
+    case $1 in
+        -m|--machine)
+        MACHINE_READABLE=true
+        shift # past argument
+        ;;
+        -h|--help)
+        usage
+        exit 1
+        ;;
+        -*|--*)
+        echo "Unknown option $1"
+        usage
+        exit 1
+        ;;
+        *)
+        POSITIONAL_ARGS+=("$1") # save positional arg
+        shift # past argument
+        ;;
+    esac
 done
+
+set -- "${POSITIONAL_ARGS[@]}" # restore positional parameters
+
+
+if [ -n "${1}" ]; then
+    check "${1}"
+else
+    for datafile in "${RULES_DIR}"*.data; do
+        check "${datafile}"
+    done
+fi