Set EXIF dates based on filename on selected pictures

#!/bin/bash

function readdates {
    output=$( exiftool "-TAG" "-createdate" "-modifydate" "-metadatadate" "-datetime" "-datetimeoriginal" "-dateutc" "-modificationdate" "-datecreated" "-datetimecreated" "$i" )
}


echo "$# arguments"
if [ "$#" -lt 1 ]
then
    echo "Not enough arguments."
    exit 1
fi

arguments=( "$@" )

for i in "${arguments[@]}"
do
    echo "$i"
    readdates
    echo "Current EXIF date info: "
    echo -e "$output"
    if [ -z "$output" ]
    then
        # output is empty - success - leave the loop:
        echo "The pictures currently do not have any dates."
        # Desem la data
        echo "Saving date..."
        exiftool "-alldates<"filename "-overwrite_original" "$i"
        echo "...done."
        readdates
        echo "New EXIF date info: "
        echo -e "$output"
    else
        # output is non-empty - continue:
        echo "The picture already has date information."
        read -p "Do you want to remove it and set it again? [y/n] " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]
        then
            echo  "Ok. Let's update the date..."
            exiftool "-alldates=" "-overwrite_original" "$i" # remove dates
            exiftool "-alldates<"filename "-overwrite_original" "$i"
            echo "...done."
            readdates
            echo "New EXIF date info: "
            echo -e "$output"
        else
            echo "Ok. Nothing was changed."
        fi
    fi
    echo ""
done
sleep 5