You are not logged in. Your edit will be placed in a queue until it is peer reviewed.
We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.
Required fields*
How to Edit
- Correct minor typos or mistakes
- Clarify meaning without changing it
- Add related resources or links
- Always respect the author’s intent
- Don’t use edits to reply to the author
How to Format
-
create code fences with backticks ` or tildes ~
```
like so
``` -
add language identifier to highlight code
```python
def function(foo):
print(foo)
``` - put returns between paragraphs
- for linebreak add 2 spaces at end
- _italic_ or **bold**
- indent code by 4 spaces
- backtick escapes
`like _so_` - quote by placing > at start of line
- to make links (use https whenever possible)
<https://example.com>[example](https://example.com)<a href="https://example.com">example</a>
How to Tag
A tag is a keyword or label that categorizes your question with other, similar questions. Choose one or more (up to 5) tags that will help answerers to find and interpret your question.
- complete the sentence: my question is about...
- use tags that describe things or concepts that are essential, not incidental to your question
- favor using existing popular tags
- read the descriptions that appear below the tag
If your question is primarily about a topic for which you can't find a tag:
- combine multiple words into single-words with hyphens (e.g. shell-script), up to a maximum of 35 characters
- creating new tags is a privilege; if you can't yet create a tag you need, then post this question without it, then ask the community to create it for you
ed,grep, andsedall uses basic regular expressions by default. Alterations are not part of the this type of regular expressions.grepandsedcan often be made to use extended regular expressions as a non-standard extension, which includes alterations. GNUgrepalso supports Perl-compatible regular expressions, as a further extension to the POSIX specification for this utility. This is not an answer as it says nothing about why alterations were not part of the basic regular expression syntax (which is what I believe the question is really about).