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How to Edit
- Correct minor typos or mistakes
- Clarify meaning without changing it
- Add related resources or links
- Always respect the author’s intent
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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
‘[_[:alnum:]]’means?[ ... ]is a "character list", so this matches any single character contained in the square brackets (think of it as a convenient "OR" of single characters, only with the possibility to easily define ranges, as in[a-z]. The[:alnum:]within that character list is a "character class" - a POSIX extension to regular expressions and again a shorthand method for defining "umbrella" character lists.[:alnum:]contains all "alphanumeric" characters, i.e. alphabetic characters+numbers. So,[_[:alnum:]]matches alphanumeric chars plus the underscore.