====== Regex - All Text Not Containing ======

===== Text that does not contain ~ =====

<code>
[^~\x22]+
</code>

----

===== Match anything except \n =====

<code>
.*
</code>

----

===== Match strings that do not start with a sequence =====

Ignore strings that start with the label "abc_".

Use a negative look-ahead assertion:

<code bash>
^(?!abc_).+
</code>

Or, use a negative look-behind assertion:

<code bash>
(^.{1,3}$|^.{4}(?<!abc_).*)
</code>

Or, use plain old character sets and alternations:

<code bash>
^([^a]|a($|[^b]|b($|[^c]|c($|[^_])))).*
</code>

----

===== Match strings that do not end in particular sequence =====

Use a negative lookbehind assertion:

<code bash>
^[/\w\.-]+(?<!\.html)$
</code>

or, use a lookahead:

<code bash>
^(?!.*\.html$)[/\w\.-]+$
</code>

or, another use of a lookahead assertion:

<code bash>
/((?!\.html$)[/\w.-])+/
</code>

<WRAP info>
**NOTE:**

  * **(** - Start a group for the purposes of repeating.
  * **(?!\.html$)** - Negative lookahead assertion for the pattern **/\.html$/**.
  * **[/\w.-]** - The pattern for matching a URL character.
  * **)+** - Repeat the group.


To force it to match the entire string, anchor the entire pattern with **^** at the start and **$** at the end; otherwise it is free to only match a portion of the string. With this change, it becomes:

<code bash>
/^((?!\.html$)[/\w.-])+$/
</code>


</WRAP>


----

===== References =====

https://www.regular-expressions.info/lookaround.html