Jorge Saldívar

Author: Jorge Saldivar

Updated website to TT4

I’m vibing on the updated default theme, Twenty Twenty-Four. Great job to the contributors!

Photo by Johannes Plenio on Pexels.com

November 8, 2023
Regex Cheat Sheet
Simple Examples
- hello: Matches the string “hello” exactly.
- 123: Matches the string “123” exactly.
- .: Matches any single character.
- \d: Matches any digit character (0-9).
- \w: Matches any word character (a-z, A-Z, 0-9, _).
- \s: Matches any whitespace character (space, tab, newline).
Examples
- hello world: Matches the string “hello world” exactly.
- hello|world: Matches either “hello” or “world”.
- hello.*: Matches “hello” followed by zero or more characters.
- hello\s: Matches “hello” followed by a whitespace character.
- hello\d: Matches “hello” followed by a digit character.
- hello\w: Matches “hello” followed by a word character.
- hello\s\d: Matches “hello” followed by a whitespace character and a digit character.
Quantifiers
- a+: Matches one or more “a” characters.
- a*: Matches zero or more “a” characters.
- a?: Matches zero or one “a” character.
- a{3}: Matches exactly three “a” characters.
- a{3,}: Matches three or more “a” characters.
- a{3,5}: Matches between three and five “a” characters.
Character Classes
- [abc]: Matches any of the characters “a”, “b”, or “c”.
- [^abc]: Matches any character that is not “a”, “b”, or “c”.
- [a-z]: Matches any lowercase letter.
- [A-Z]: Matches any uppercase letter.
- [0-9]: Matches any digit character.
- [\w]: Matches any word character.
- [\W]: Matches any non-word character.
- [\s]: Matches any whitespace character.
- [\S]: Matches any non-whitespace character.
Anchors
- ^hello: Matches “hello” at the beginning of a line.
- world$: Matches “world” at the end of a line.
- \bhello\b: Matches “hello” as a whole word.
- \Bhello\B: Matches “hello” not as a whole word.
Groups
- (hello): Matches “hello” and captures it as a group.
- (hello|world): Matches either “hello” or “world”.
- (?:hello): Matches “hello” but does not capture it as a group.
- (?=hello): Matches any string that is followed by “hello”.
- (?!hello): Matches any string that is not followed by “hello”.
Flags
- /hello/i: Matches “hello” case-insensitively.
- /hello/g: Matches all occurrences of “hello”.
- /hello/m: Matches “hello” across multiple lines.
- /hello/s: Matches “hello” across multiple lines and allows “.” to match newline characters.
Special Characters
- \: Escapes a special character.
- .: Matches any single character except newline characters.
- ^: Matches the beginning of a line.
- $: Matches the end of a line.
- *: Matches zero or more of the preceding character.
- +: Matches one or more of the preceding character.
- ?: Matches zero or one of the preceding character.
- (: Begins a capturing group.
- ): Ends a capturing group.
- [: Begins a character class.
- ]: Ends a character class.
- {: Begins a quantifier.
- }: Ends a quantifier.
- |: Matches either the expression before or after the operator.
- /: Begins and ends a regular expression.
- i: Makes the regex case-insensitive.
- g: Matches all occurrences of the pattern.
- m: Makes the ^ and $ anchors match the beginning and end of lines.
- s: Allows . to match newline characters.
- \n: Matches a newline character.
- \r: Matches a carriage return character.
- \t: Matches a tab character.
- \v: Matches a vertical tab character.
- \0: Matches a null character (U+0000 NULL).
- \xhh: Matches a character with the given hex code (e.g. \x0A matches a newline character).
- \uhhhh: Matches a character with the given Unicode code point (e.g. \u0009 matches a tab character).
- \cX: Matches a control character using caret notation (e.g. \cJ matches a newline character).
- \u{hhhh}: Matches a character with the given Unicode code point (e.g. \u{0009} matches a tab character).
Lookarounds
- (?=hello): Positive lookahead. Matches any string that is followed by “hello”.
- (?!hello): Negative lookahead. Matches any string that is not followed by “hello”.
- (?<=hello): Positive lookbehind. Matches any string that is preceded by “hello”.
- (?<!hello): Negative lookbehind. Matches any string that is not preceded by “hello”.
Unicode Categories
- \p{L}: Matches any letter character.
- \p{M}: Matches any combining mark character.
- \p{Z}: Matches any separator character.
- \p{S}: Matches any symbol character.
- \p{N}: Matches any number character.
- \p{P}: Matches any punctuation character.
- \p{C}: Matches any control character.
- \p{Ll}: Matches any lowercase letter.
- \p{Lu}: Matches any uppercase letter.
- \p{Lt}: Matches any titlecase letter.
- \p{L&}: Matches any letter character.
- \p{Lm}: Matches any modifier letter.
- \p{Lo}: Matches any other letter character.
- \p{Mn}: Matches any non-spacing mark character.
- \p{Mc}: Matches any spacing combining mark character.
- \p{Me}: Matches any enclosing mark character.
- \p{Zs}: Matches any space separator character.
- \p{Zl}: Matches any line separator character.
- \p{Zp}: Matches any paragraph separator character.
- \p{Sm}: Matches any mathematical symbol character.
- \p{Sc}: Matches any currency symbol character.
- \p{Sk}: Matches any modifier symbol character.
- \p{So}: Matches any other symbol character.
- \p{Nd}: Matches any decimal digit character.
- \p{Nl}: Matches any letter number character.
- \p{No}: Matches any other number character.
- \p{Pc}: Matches any connector punctuation character.
- \p{Pd}: Matches any dash punctuation character.
- \p{Ps}: Matches any open punctuation character.
- \p{Pe}: Matches any close punctuation character.
- \p{Pi}: Matches any initial punctuation character.
- \p{Pf}: Matches any final punctuation character.
- \p{Po}: Matches any other punctuation character.
- \p{Cc}: Matches any control character.
- \p{Cf}: Matches any format character.
- \p{Cs}: Matches any surrogate character.
- \p{Co}: Matches any private-use character.
- \p{Cn}: Matches any unassigned code point.
POSIX Classes
- [:alnum:]: Matches any alphanumeric character.
- [:alpha:]: Matches any alphabetic character.
- [:ascii:]: Matches any ASCII character.
- [:blank:]: Matches any whitespace character.
- [:cntrl:]: Matches any control character.
- [:digit:]: Matches any digit character.
- [:graph:]: Matches any visible character.
- [:lower:]: Matches any lowercase character.
- [:print:]: Matches any printable character.
- [:punct:]: Matches any punctuation character.
- [:space:]: Matches any whitespace character.
- [:upper:]: Matches any uppercase character.
- [:word:]: Matches any word character.
- [:xdigit:]: Matches any hexadecimal digit character.
November 6, 2023
Trex with feathers

I asked GPT-4 to generate an image of a tyrannosaurus rex with feathers like a chicken… it did not disappoint on the first image it created. Subsequent photos weren’t as impressive.

November 5, 2023
LAMP Stack Setup
Setup for Ubuntu 20.04 LTS or 22.04 LTS. Lifted from this resource on AWS.

Linux

WSL, Ubuntu Multipass, or equivalant.

Apache

Version: distribution
```
sudo apt update -y
sudo apt install apache2 -y
```
PHP FPM

Version: 8.2

Run the following commands to install PHP:
```
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt-get update -y
sudo apt install php8.2 php8.2-{fpm,mysql,curl,gd,mbstring,mysql,xml,mcrypt,zip,ldap} libapache2-mod-php8.2 -y
```
Install PHP-FPM
```
sudo a2enmod proxy_fcgi setenvif
sudo a2enconf php8.2-fpm
sudo a2dismod php8.2
sudo systemctl enable php8.2-fpm
sudo service apache2 restart;sudo service php8.2-fpm restart
```
MariaDB

Version: 11.1.2

Run the following command to add the MariaDB yum repository (For all Linux distributions):
```
curl -LsS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash -s -- --mariadb-server-version="mariadb-11.1.2"
```
Install MariaDB Package
```
sudo apt install mariadb-server -y
```
MariaDB Secure Installation
```
sudo mysql_secure_installation
```
When prompted, set a password for the root account:
- Enter the current root password. By default, the root account doesn’t have a password set.
- Press Enter.
- Press N to switch to unix_socket authentication.
- Press Y to set a password, and then enter a secure password twice. Make sure to store this password in a safe place.
- Press Y to remove the anonymous user accounts.
- Press Y to disable the remote root login.
- Press Y to remove the test database.
- Press Y to reload the privilege tables and save your changes.
Permissions

The following command will add the ubuntu user to the www-data group:
```
sudo usermod -a -G www-data ubuntu
```
The following commands will set the correct permissions for the /var/www directory:
```
sudo chown -R ubuntu:www-data /var/www
sudo chmod 2775 /var/www
find /var/www -type d -exec sudo chmod 2775 {} \;
find /var/www -type f -exec sudo chmod 0664 {} \;
```
Your site is ready!

Visit your website by entering your instance’s public IP address in your browser. You should see the default Apache page.
October 21, 2023
Savage

October 18, 2023
Common Git Commands

I have a variation of this posted on this site. Leaving this updated version here.

October 17, 2023
Microblog testing

Don’t mind this post. It’s just a test.

October 17, 2023
The difference between .splice() and .slice()

While perusing some forums, I ran into someone expressing not knowing the difference between .splice() and .slice() unless they googled it.

October 16, 2023
JavaScript String Cheat Sheet v2

I was looking through the site for the old post, which was… less than helpful. Here’s the updated cheat sheet for quick reference.

October 16, 2023
ActivityPub, Friends, and WP Code plugins

I’m trying out the ActivityPub and Friends WordPress plugins on this website. Also, using the WP Code plugin to add the following snippet of code, site wide.

October 16, 2023