sed con variable
sed -i "s/$var1/ZZ/g" "$file"
Devops Captain
sed -i "s/$var1/ZZ/g" "$file"
# If you want to store your regex in a bash variable
# and use it in sed, you might need the following
BASE_REGEX="[0-9]{4}\.[0-9]+"
REGEX_ESCAPED=$(sed 's/[}{)(+]/\\&/g; s/\^/\\^/g' <<< "$BASE_REGEX")
# One variable can be used with sed
sed -i "s/${REGEX_ESCAPED}/REPLACEMENT/g" file.txt
# The other can be used with bash internal regex operator
if [[ "2022.42" =~ ^${BASE_REGEX}$ ]]
then
echo 'Matches !'
fi