BASH will not know that you are attempting to assign something. The parser will see varname with no = and treat it as a command name, and then pass = and vardata to it as arguments. Match tilde, hash or colon special characters that have either a word character or a string-end on each side, you can...

Hunts for the key and value in environment variables separated by newlines. _ All keys must be uppercase _

This regex will separate KEY=VALUE when VALUE has special characters that cause bash to misinterpret them

Exclude certain tags with OR

This is a number also 123-456-7890 This is not a number: 123456 This is not a number, but an address 123 456 My parameters are 90/60/90 - 120/150/120 - not a phone number I am cheeky and I use letter 0 instead of zero 604_213_0293 Or I use | symbol and also 604_2|3_0293 may happen...