PHP - Tips & snippets for configuration and development

What is New Relic ?

PHP APM : Enable the agent :

PHP APM : Configuring the application name (source) :

The upgrade from Debian 8.10 to 9.3 involved upgrading to PHP7.0. After that, I got an error from a web application saying :

"Can not connect to database. Make sure the 'mysqli' extension is enabled"

SOLUTION :
	apt install php7.0-cgi php-mysql
	systemctl restart lighttpd

SOURCE :
	https://stackoverflow.com/questions/35424982/how-to-enable-mysqli-extension-in-php-7


VALUES RETURNED BY phpinfo() :
Configuration File (php.ini) Path	/etc/php/7.0/cgi
Loaded Configuration File		/etc/php/7.0/cgi/php.ini

=====================================================================================================

2017-12-13 11:31:10: (mod_fastcgi.c.2543) FastCGI-stderr: PHP Fatal error:  Uncaught Error: Call to undefined function utf8_encode() in /var/www/xxxxxxxx/index.php:552

SOLUTION :
	apt install php7.0-xml && systemctl restart lighttpd

SOURCE :
	https://stackoverflow.com/questions/35701730/utf8-endecode-removed-from-php7#answer-36902105

• Where should I download package from ?
• How can I upgrade PHP without installing Apache ?

For PHP7.0 on Debian Jessie (8.x)

php_flag	log_errors	on
php_value	error_log	/path/to/php_errors.log

How to perform an HTTP redirect :

<?php
$newDomainName = 'new.example.tld';

header(
	"Location: http://$newDomainName".$_SERVER['REQUEST_URI'],
	True,
	301
	);

How to send an email :

<?php

$from		= 'test@domain.tld';		you can put anything here
$to		= 'john.smith@gmail.com';
$subject	= 'This is the subject';
$message	= 'Hello World !';
$headers	= "From: $from\r\n" .
			"Reply-To: $from\r\n" .
			'X-Mailer: PHP/' . phpversion();

if(mail($to, $subject, $message, $headers)) {
	print "Mail sent\n";
	}
else {
	print "Ooops\n";
	}

How to test a DB connection (source) :

<?php

$dbHost		= 'myServer';
$dbName		= 'myDatabase';
$dbUser		= 'user';
$dbPassword	= 'password';
$dbTable	= 'myTable';

$dsn		= sprintf("mysql:dbname=$dbName;host=$dbHost");
$driverOptions	= array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8');
$dbConnection	= new PDO($dsn, $dbUser, $dbPassword, $driverOptions);

$sql		= "select count(1) from $dbTable;";
$resultSet	= $dbConnection->query($sql);
foreach($resultSet as $result) {
	print("$result[0]\n");
	}

List all known .ini files :

php --ini

Absolute path to currently loaded .ini file :

• php --ini | grep -i loaded
• phpinfo()

Directives :

Several php.ini files :

For complete details on PHP configuration, you can create a short PHP file containing :

<?php phpinfo(); ?>

Alternate methods (source) :

• php -i : (-i/--info : PHP information and configuration)
• echo '<?php phpinfo(); ?>' | php , then grep / > / ...
• php -r "phpinfo();" : (-r/--run : run specified code)
• php -r 'echo(ini_get("memory_limit"))."\n";'

Details on SSL/TLS support :

php -m

Xdebug should appear twice : once under PHP Modules and once under Zend Modules (source).

Trigger errors

trigger_error('ARGL !', E_USER_NOTICE)

Show errors :

ini_set('log_errors', 'off');
ini_set('display_errors', 'on');

Show errors (alternate) :

ini_set('log_errors', 'on');
ini_set('error_log', '/path/to/logFile.log');

/path/to/logFile.log must be writable by the web server's user.

$_SERVER['SERVER_NAME'] (explicit) is supposed to handle the "server name", but this name can have several values. It is possible to tune Apache to control which value is affected to this variable.

This is done by editing /etc/httpd/conf/httpd.conf and change the value of the parameter UseCanonicalName :

$_SERVER['SERVER_NAME'].':'.$_SERVER['SERVER_PORT'] is equivalent to $_SERVER['HTTP_HOST']

1. Enable the corresponding PHP extensions (they are bundled with the PHP installation files) :
   • php_oracle.dll : obsolete
   • php_oci8.dll : this is the Oracle Call Interface. This allows connecting to Oracle 8.1.7, 9.x, or 10.x databases.
     • Details from the PHP site
     • Details from the Oracle site
2. php_oci8.dll allows the use of PHP functions such as oci_connect(), but these functions are defined in the Oracle client libraries. Follow this procedure to install these libraries. Basically, you have to :
   1. Download the Instant Client Basic package
   2. On the server running PHP, create a directory to store the Oracle client libraries. Let's say : C:\Oracle
   3. Extract these 3 DLLs into C:\Oracle :
      • oraociei10.dll
      • orannzsbb10.dll
      • oci.dll
   4. Edit system environment variables :
      • Add C:\Oracle to the PATH variable. Place it before any other Oracle-related stuff.
      • Create and set TNS_ADMIN to value C:\Oracle
      • Create and set NLS_LANG to value .AL32UTF8 (UTF-8)
3. Restart the web service.

• being moved to a different server
• a PHP upgrade

On recent PHP versions :

PHP Parse error: syntax error, unexpected end of file in /path/to/file.php on line 294

On older ones :

Parse error: syntax error, unexpected $end in /path/to/file.php on line 84

After that, make sure you have only short open tags (<?, but no <?php) in your code, otherwise the error may still occur.