# Linux
sed -i -e "s@<TOKEN>@${avar}@g" file.yaml
# macOS
sed -i "" -e "s@<TOKEN>@${avar}@g" file.yaml
# Solution
function sed_i {
if test "$(uname)" == "Darwin"
then
sed -i '' "$@"
return $?
else
sed -i "$@"
return $?
fi
}