Question: How to match missing period (.) before end tag using regex? 

To make myself clear, here's a sample: 

Samples need match:

```
1. text</… ></tag> ---> Where </...> is any tag and can be multiple end tags

2. text</tag>  

```

Correct samples that don't need to match:

```
1. text.</...></tag>
2. text.</tag>

```

and I want to ignore something like this: 

```
,</tag>   --> Where , can be any punctuation except period (.)

```

or

```
,</...></tag>

```

I hope someone can help me thanks alot!

Answer: 
Just simply use `[^\.]`. This will match anything but `.` 
In your case you need to use `[^\.>]</`
`[,;:]` will match any punctuation *except* period. Extend at your leisure (as I'm not sure whether you want chars like apostrophe, quotation, slash etc.)

You can also negate that by using `[^,;:]`, where `^` stands for NOT in the character set.

See [this](http://www.regular-expressions.info/reference.html) for reference.