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programming:php
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Table of Contents
PHP Programming
PHP is a web-native language that essentially embeds itself within HTML.
While the wiki is still being built, refer to: https://www.devdungeon.com/topics/php and https://github.com/DevDungeon/Cookbook/tree/master/php
Installing
In Debian and most Linux distributions, it's as simple as using the package manager:
apt install php php-pdo-sqlite php --version # For Apache2 httpd apt install apache2 libapache2-mod-php
See the web servers page for more info on configuring
Built-in webserver
PHP has a built-in web server that is useful for local developing and testing.
# Serves current directory, no directory listing php -S localhost:9999 # Specify path to serve php -S localhost:9999 -t /path/to/serve
Phar files
Phar files are essentially tarballs of PHP content. In addition to the convenience of having a single .phar containing many files, the phar can be marked executable and treated like an executable Java JAR. See the official phar documentation.
It can be treated as a special protocol for referencing files like this: phar:myphar.phar/file.php. You can read or include files in this manner.
===== Composer =====
Refer to: https://www.devdungeon.com/content/php-composer-basics
===== Code examples =====
Here are some snippets for reference.
==== Hello world ====
Here is a simple “Hello world” application.
<code php hello.php>
<?php
echo “Hello, world!”;
</code>
==== Show all errors ====
<code php show_errors.php>
<?php
Add this to turn on all errors (disable in production!)
The ini_set options could also go in php.ini
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
</code>
==== Functions ====
<code php functions.php>
<?php
function greet($name, $greeting=“Hi”) {
print(“$greeting, $name!”);
}
greet(“NanoDano”); Hi, NanoDano!
</code>
==== Include a PHP file ====
<code php load_lib.php>
<?php
Pick one method for loading another PHP file
include('my_lib.php'); Include if available
require('my_lib.php'); Fail if not available
require_once('my_lib.php'); Ensure not loaded twice
</code>
==== Forms ====
<code php form.php>
<html>
<body>
<?php
if ($_POST['something']) {
print(“Received: ” . $_POST['something'];
}
<form method=“post”>
<input type=“text” name=“something” id=“something” />
<br />
<button type=“submit”>Submit</button>
</form>
</body>
</html>
</code>
==== Redirect ====
Use the PHP function header() to send a new Location header.
<code php redirect.php>
<?php
Set HTTP header to redirect
Must go before any content is output
header('Location: /'); Defaults to 302
Or specify status code
header('Location: /', TRUE, 301);
exit; If you want to ensure nothing else gets output
</code>
==== SQLite database ====
This example is for SQLite3 using the PHP PDO_SQLITE, but essentially the same for other databases too.
apt install php-pdo-sqlite
<code php sqlite_example.php>
<?php
Connect (Use `sqlite::memory:` for memory-only)
$db = new PDO('sqlite:'.DIR.'/bookmarks.sqlite3');
Create table
$db→exec(
“CREATE TABLE IF NOT EXISTS urls (
url TEXT,
notes TEXT
)”
);
Prepared statement for changes
$query = $db→prepare('INSERT INTO urls (url) VALUES (?)');
$query→execute(['https://www.devdungeon.com/']);
Query
$result = $db→query('SELECT * FROM urls');
foreach ($result as $result) {
print($result['url'].'<br />');
}
$db = null; Close it
</code>
programming/php.1618364076.txt.gz · Last modified: 2021/04/14 01:34 by nanodano
