kellerkruz

storyboard="path-to-storyboard"
constants="path-to-constants-file"

while read -r line || [[ -n "$line" ]]; do
    propName=$(echo $line | grep "static let" | sed 's/static let \([^ ]*\): CGFloat =.*$/\1/' | sed 's/\n//g')
    propValue=$(echo $line | grep "static let" | sed 's/.*CGFloat = \(.*$\)/\1/' | sed 's/\n//g')
    if [ "x$propValue" != "x" ] && [ "x$propName" != "x" ]; then
        sed -i '' "s/^\(.*<constraint.*\)constant=\"[^\"]*\" \(.*userLabel=\"${propName}\".*\)$/\1\2/g" $storyboard
        sed -i '' "s/^\(.*<constraint.*\)\(id=\"[^\"]*\".*userLabel=\"${propName}\".*\)$/\1constant=\"${propValue}\" \2/g" $storyboard
    fi