Kenneth: /* MySQL */

2018-01-04T05:43:05Z

MySQL

New page

==PHP==

== Code ==

=== variables ===

Variable:
$str = "string";
$int = 1;
$flt = 3.141;
$obj = new Object();
$arry = array(1, 2, 3);
$empty_array = array();
$null = NULL;

global variable: (to access inside function)
$var = 1
function a() {
global $var;
}

Check if variable is empty:
empty($var)

Check if variable is set:
isset($var)

=== [http://us3.php.net/manual/en/language.control-structures.php Control Structures] ===

<pre>
if
else
elseif/else if
while
do-while
for
foreach
break
continue
switch
declare
return
require
include
require_once
include_once
goto
</pre>

=== [http://us3.php.net/manual/en/control-structures.if.php if] ===

Comparison Operators: [http://us3.php.net/manual/en/language.operators.comparison.php]
> (bigger than)
>= (bigger than or equal to)
== (equal)
!= (not equal)
<> (not equal)
< (smaller than)
<= (smaller than or equal to)

Strict equivalence operators:
=== (equal to and same type)
!== (not equal to or not same type)

Logical Operators: [http://us3.php.net/manual/en/language.operators.logical.php]
<pre>
Example Name Result
$a and $b And TRUE if both $a and $b are TRUE.
$a or $b Or TRUE if either $a or $b is TRUE.
$a xor $b Xor TRUE if either $a or $b is TRUE, but not both.
! $a Not TRUE if $a is not TRUE.
$a && $b And TRUE if both $a and $b are TRUE.
$a || $b Or TRUE if either $a or $b is TRUE.
</pre>

Ternary Operator - http://php.net/manual/en/language.operators.comparison.php:
(expr1) ? (expr2_on_true) : (expr3_on_false);
$var = (expr1) ? (expr2_on_true) : (expr3_on_false) ;
$action = (empty($_POST['action'])) ? 'default' : $_POST['action'];

=== for ===

<pre>
for (setup_expr1; cond_expr2; loop_expr3)
statement
</pre>

for ($i = 1; $i <= 10; $i++) {
echo $i;
}

=== foreach ===

Note: foreach works only on arrays and '[http://us3.php.net/manual/en/language.oop5.iterations.php iterate objects]'

<pre>
foreach (array_expression as $value)
statement
foreach (array_expression as $key => $value)
statement
</pre>

foreach( $myarray as $value) { ... }
foreach( $myarray as $key => $value) { ... }

=== while ===

while( [statement] ) { ... }

=== break and continue ===

break - ends execution of the current for, foreach, while, do-while or switch structure.

for(...) {
...
break; # exit for loop
}

continue - is used within looping structures to skip the rest of the current loop iteration and continue execution at the condition evaluation and then the beginning of the next iteration.

for(...) {
...
continue; # continue to next iteration
}

=== switch ===

Series of IF statements (similar to 'case statment' in other languages)

<pre>
switch ($i) {
case 0:
echo "i equals 0";
break;
default:
echo "i is not equal to 0";
}
</pre>

=== [http://www.php.net/manual/en/ref.strings.php Strings] ===

Lower case: [http://php.net/manual/en/function.strtolower.php]
strtolower( string $str );

Upper case: [http://www.php.net/manual/en/function.strtoupper.php]
strtoupper( string $str );

Heredoc: [http://php.net/manual/en/language.types.string.php]
<pre>
$str = <<<EOD
Example of string
spanning multiple lines
using heredoc syntax.
This variable is evaluated: $var
EOD;
</pre>

=== phpinfo ===

phpinfo - http://php.net/manual/en/function.phpinfo.php

phpinfo();

To see if mysql is supported:
echo "<?php phpinfo(); ?>" | php | grep -i "mysql support"

=== file io ===

fopen — Opens file or URL: [http://us3.php.net/manual/en/function.fopen.php]
# resource fopen ( string $filename , string $mode [, bool $use_include_path = false [, resource $context ]] )
$handle = fopen("/home/rasmus/file.txt", "r");

<pr>
mode Description
'r' Open for reading only; place the file pointer at the beginning of the file.
'r+' Open for reading and writing; place the file pointer at the beginning of the file.
'w' Open for writing only; place the file pointer at the beginning of the file and truncate
the file to zero length. If the file does not exist, attempt to create it.
'w+' Open for reading and writing; place the file pointer at the beginning of the file and
truncate the file to zero length. If the file does not exist, attempt to create it.
'a' Open for writing only; place the file pointer at the end of the file. If the file
does not exist, attempt to create it.
'a+' Open for reading and writing; place the file pointer at the end of the file. If the file
does not exist, attempt to create it.
</pre>

==== read ====

Make array of lines of file:
$lines = file( $file );

Read line from file: (1024 byte buffer)
$line = fgets( $file, 1024 );

readfile - Reads a file and writes it to the output buffer: [http://us3.php.net/manual/en/function.readfile.php]
# int readfile ( string $filename [, bool $use_include_path = false [, resource $context ]] )
readfile( $file );

file — Reads entire file into an array: [http://us3.php.net/manual/en/function.file.php]
# array file ( string $filename [, int $flags = 0 [, resource $context ]] )
$lines = file('http://www.example.com/');

fread — Binary-safe file read: [http://us3.php.net/manual/en/function.fread.php]
# string fread ( resource $handle , int $length )

<pre>
// get contents of a file into a string
$filename = "/usr/local/something.txt";
$handle = fopen($filename, "r");
$contents = fread($handle, filesize($filename));
fclose($handle);
</pre>

Reading a file line by line:
<pre>
$handle = @fopen("/tmp/inputfile.txt", "r");
if ($handle) {
while (($buffer = fgets($handle, 4096)) !== false) {
echo $buffer;
}
if (!feof($handle)) {
echo "Error: unexpected fgets() fail\n";
}
fclose($handle);
}
</pre>

==== write ====

fwrite — Binary-safe file write: [http://us3.php.net/manual/en/function.fwrite.php]
# int fwrite ( resource $handle , string $string [, int $length ] )

$fp = fopen('data.txt', 'w') or die('unable to open for writing');
fwrite($fp, '1');
fclose($fp);

=== Include other PHP Code ===

include - statement includes and evaluates the specified file
include_once - statement includes and evaluates the specified file only if not already loaded
require - is identical to include() except upon failure it will also produce a fatal E_COMPILE_ERROR level error.
require_once - statement is identical to require() except PHP will check if the file has already been included

include 'vars.php';

=== Date and Time ===

date - Format a local time/date [http://us3.php.net/manual/en/function.date.php]
# string date ( string $format [, int $timestamp = time() ] )
$strdate = date('Y-m-d');
# 2010-06-01

<pre>
format Example

Day
d 01 to 31
D Mon, Sun
j 1 to 31
w 0 (sun) to 6 (sat)
z 0 to 365

Month
n 1 to 12
m 01 to 12
M Jan to Dec

Year
Y 1999
y 99

Time
g 1 - 12
a am / pm
G 0 - 23
h 01 - 12
H (hr) 01 - 23
i (min) 00 - 59
s (sec) 00 - 59
U Seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)
</pre>

=== HTTP POST and GET and REQUEST ===

$var = $_POST["param"];
$var = $_GET["param"];
$var = $_REQUEST["param"]; # includes GET, POST, and COOKIE
# order is based on PHP variables_order configuration directive

$user = empty($_REQUEST["user"]) ? '' : trim($_REQUEST["user"]);

=== $_SERVER ===

<pre>
$_SERVER["HTTP_HOST"] # default.t0e.org
$_SERVER["SERVER_NAME"] # default.t0e.org
$_SERVER["SERVER_ADDR"] # 24.2.94.68
$_SERVER["REMOTE_ADDR"] # 10.10.10.5
$_SERVER["DOCUMENT_ROOT"] # /www/default
$_SERVER["SCRIPT_FILENAME"] # /www/default/index.php
$_SERVER["REQUEST_METHOD"] # GET
$_SERVER["SCRIPT_NAME"] # /index.php
$_SERVER["PHP_SELF"] # /index.php
</pre>

Default error page: (don't forget space at end)
<pre>
<h1><font color="red">Unauthorized!</font></h1>

</pre>

=== [http://www.php.net/manual/en/ref.pcre.php Regular Expression] ===

Match: [http://php.net/manual/en/function.preg-match.php]
# int preg_match ( string $pattern , string $subject [, array &$matches [, int $flags = 0 [, int $offset = 0 ]]] )
findcount = preg_match('/^([a-zA-Z0-9_]*)$/', $user )
findcount = preg_match('/^([a-zA-Z0-9_]*)$/', $user, $matches )
echo $matches[1]; # first paren match

$matches will be an array filled with captured parenthesized subpattern (0 will have full pattern, 1 will have first match)

=== [http://www.php.net/manual/en/ref.exec.php External Command Execution] ===

exec — Execute an external program: (output to return string)
# string exec ( string $command [, array &$output [, int &$return_var ]] )
$lastline = exec( $command, $output, $return_var );
exec( $command, $output = array() );

passthru — Execute an external program and display raw output: (output to buffer)
# void passthru ( string $command [, int &$return_var ] )
passthru( $command, $return_var );

system — Execute an external program and display the output: (output to buffer)
string system ( string $command [, int &$return_var ] )
$lastline = system( $command, $return_var );

Source: [http://us.php.net/manual/en/function.passthru.php PHP: passthru - Manual]

=== File System ===

PHP: file_exists - Manual - http://php.net/manual/en/function.file-exists.php
bool file_exists ( string $filename )

PHP: rename - Manual - http://php.net/manual/en/function.rename.php
bool rename ( string $oldname , string $newname [, resource $context ] )

=== [http://us3.php.net/manual/en/book.mail.php email] ===

ini_set("SMTP","smtp.example.com" );
ini_set('sendmail_from', 'user@example.com');

mail - Send mail [http://us3.php.net/manual/en/function.mail.php]
# bool mail ( string $to , string $subject , string $message [, string $additional_headers [, string $additional_parameters ]] )

To Addresses in this format:
user@example.com
user@example.com, anotheruser@example.com
User <user@example.com>
User <user@example.com>, Another User <anotheruser@example.com>

NOTE NOTE: I had to use "\n" instead of "\r\n" to work on an older debian system!

<pre>
$to = 'nobody@example.com';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: webmaster@example.com' . "\r\n" .
'Reply-To: webmaster@example.com' . "\r\n" .
'X-Mailer: PHP/' . phpversion();

mail($to, $subject, $message, $headers);
</pre>

HTML email:
<pre>
// To send HTML mail, the Content-type header must be set
$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";

// Additional headers
$headers .= 'To: Mary <mary@example.com>, Kelly <kelly@example.com>' . "\r\n";
$headers .= 'From: Birthday Reminder <birthday@example.com>' . "\r\n";
$headers .= 'Cc: birthdayarchive@example.com' . "\r\n";
$headers .= 'Bcc: birthdaycheck@example.com' . "\r\n";

// Mail it
mail($to, $subject, $message, $headers);
</pre>

=== MySQL ===

--- mysqli ---

<pre>
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT id, firstname, lastname FROM MyGuests";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
}
} else {
echo "0 results";
}
$conn->close();
?>
</pre>

Select - https://www.w3schools.com/php/php_mysql_select.asp

Insert - https://www.w3schools.com/php/php_mysql_insert.asp

--- old style ---

<pre>
<?php
// Connecting, selecting database
$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')
or die('Could not connect: ' . mysql_error());
echo 'Connected successfully';
mysql_select_db('my_database') or die('Could not select database');

// Performing SQL query
$query = 'SELECT * FROM my_table';
$result = mysql_query($query) or die('Query failed: ' . mysql_error());

// Printing results in HTML
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "\t<tr>\n";
foreach ($line as $col_value) {
echo "\t\t<td>$col_value</td>\n";
}
echo "\t</tr>\n";
}
echo "</table>\n";

// Free resultset
mysql_free_result($result);

// Closing connection
mysql_close($link);
?>
</pre>

PHP: MySQL extension overview example - Manual - http://php.net/manual/en/mysql.examples-basic.php

---

=== [http://us3.php.net/manual/en/book.sockets.php Sockets] ===

==== [http://us3.php.net/manual/en/function.stream-socket-client.php stream_socket_client] ====

<pre>
@ $fp = stream_socket_client("tcp://localhost:60002", $errno, $errstr, 30);
if (!$fp) {
echo "FAILURE: Unable to connect to server: $errstr $errno";
die();
}
fwrite($fp, $send_data);
$recv_data = fgets($fp, 1024);
fclose($fp);
</pre>

<pre>
$fp = stream_socket_client("tcp://www.example.com:80", $errno, $errstr, 30);
if (!$fp) {
echo "$errstr ($errno)<br />\n";
} else {
fwrite($fp, "GET / HTTP/1.0\r\nHost: www.example.com\r\nAccept: */*\r\n\r\n");
while (!feof($fp)) {
echo fgets($fp, 1024);
}
fclose($fp);
}
</pre>

== Advanced Code ==

=== Upload Single File ===

<pre>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Build ESX ISO</title>
<meta charset="utf-8"/>
</head>
<body>

<?php

$upload_file = $_FILES['fileselect'];
// $upload_file is array of:
// [name] => screenshot.png
// [type] => image/png
// [tmp_name] => /tmp/phpPiUA5v
// [error] => 0
// [size] => 14537

if($upload_file) {
if ($upload_file['error'] == UPLOAD_ERR_OK) {
$fn = $upload_file['name'];
if (move_uploaded_file(
$upload_file['tmp_name'],
'uploads/' . $fn)) {
echo "<p>UPLOAD SUCCESS: $fn</p>";
} else {
echo "<p>UPLOAD FAILURE: $fn</p>";
}
}
}

?>

<form id="upload" action="single.php" method="POST" enctype="multipart/form-data">
<fieldset>
<legend>HTML File Upload</legend>
<input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="300000" />
<div>
<label for="fileselect">File to upload:</label>
<input type="file" id="fileselect" name="fileselect" />
</div>
<div id="submitbutton">
<button type="submit">Upload File</button>
</div>
</fieldset>
</form>

</body>
</html>
</pre>

References:
* PHP: move_uploaded_file - Manual - http://php.net/manual/en/function.move-uploaded-file.php
* How to Asynchronously Upload Files Using HTML5 and Ajax - SitePoint - http://www.sitepoint.com/html5-ajax-file-upload/

=== Upload Multiple Files ===

<pre>
<!DOCTYPE html>
<html lang="en">
<head>
<title>untitled</title>
<meta charset="utf-8"/>
</head>
<body>

<?php

// Note: Make sure to create an 'uploads/' folder next to this script
// and give apache permissions to write to it.

// form submit
$files = $_FILES['fileselect'];
foreach ($files['error'] as $id => $err) {
if ($err == UPLOAD_ERR_OK) {
$fn = $files['name'][$id];
if (move_uploaded_file(
$files['tmp_name'][$id],
'uploads/' . $fn)) {
echo "<p>File $fn uploaded.</p>";
} else {
echo "<p>Error: failure to upload $fn!</p>";
}
}
}
?>

<form id="upload" action="upload.php" method="POST" enctype="multipart/form-data">
<fieldset>
<legend>HTML File Upload</legend>
<input type="hidden" id="MAX_FILE_SIZE" name="MAX_FILE_SIZE" value="300000" />
<div>
<label for="fileselect">Files to upload:</label>
<input type="file" id="fileselect" name="fileselect[]" multiple="multiple" />
</div>
<div id="submitbutton">
<button type="submit">Upload Files</button>
</div>
</fieldset>
</form>

</body>
</html>
</pre>

References:
* PHP: move_uploaded_file - Manual - http://php.net/manual/en/function.move-uploaded-file.php
* How to Asynchronously Upload Files Using HTML5 and Ajax - SitePoint - http://www.sitepoint.com/html5-ajax-file-upload/

== Editors ==

Requirements:
* Syntax Highlighting
* Function reference
* Function completion

Wants:
* Jump to function
* HTML page view

Lists:
*[http://www.php-editors.com/ PHP Editor Review]
*[http://en.wikipedia.org/wiki/List_of_PHP_editors List of PHP editors - Wikipedia]
*[http://www.ibm.com/developerworks/opensource/library/os-php-ide/index.html Seven great PHP IDEs compared]

NetBeans:
*[http://php.netbeans.org/ PHP NetBeans]
**[http://blogs.vinuthomas.com/2008/09/27/netbeans-php-ide/ NetBeans PHP IDE | VT's Tech Blog]
**[http://php.netbeans.org/docs/configure-php-environment-windows.html php: Installing and configuring PHP, Apache, and MySQL for PHP development in Windows]
**[http://www.netbeans.org/kb/trails/php.html PHP Learning Trail - NetBeans IDE Tutorials, Guides and Articles]
**[http://www.netbeans.org/kb/docs/php/debugging.html Debugging PHP Source Code in the NetBeans IDE for PHP Editor]
**[http://php.netbeans.org/docs/configure-php-environment-windows.html php: Installing and configuring PHP, Apache, and MySQL for PHP development in Windows]
**FTP only (no SFTP)

Eclipse:
* [http://eclipse.org Eclipse]
** [http://www.eclipse.org/proposals/php-ide/ Eclipse PHP Integrated Development Environment] (proposal only)
** [http://www.eclipse.org/ Eclipse] (good solution)
*** Download Classic version, then install PHPEclipse plugin
** [http://www.phpeclipse.de/ PHPEclipse]
*** [http://sourceforge.net/projects/phpeclipse/ SourceForge.net: PHPeclipse - PHP Eclipse-Plugin]
*** [http://www.phpeclipse.de/wiki/Installation Installation - PHPEclipse]
** [http://www.zend.com/en/products/studio/ Zend Studio for Eclipse] ($400)
** [http://www.jcraft.com/eclipse-sftp/ SFTP Plug-in for Eclipse]
** [http://www.chris-alex-thomas.com/projects/esftp/ Eclipse SFTP Plugin (ESftp) - Homepage]
*** [http://esftp.sf.net/ Eclipse SFTP Plugin (ESftp) - Homepage] (redirected)
*** [http://sf.net/projects/esftp Eclipse SFTP Plugin (ESftp) - Sourceforge site]

==Increasing Available Memory==
The default memory limit is about 8MB:
PHP Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate ... bytes) in ...

*[http://drupal.org/node/29268 Increase memory in your php.ini]
*[http://www.mydigitallife.info/2006/04/23/php-allowed-memory-size-exchausted-fatal-error/ PHP Allowed Memory Size Exchausted Fatal Error]

==Executing External Applications==

*[http://us.php.net/manual/en/language.operators.execution.php Execution Operators]
**Description: PHP supports one execution operator: backticks (``). Note that these are not single-quotes! PHP will attempt to execute the contents of the backticks as a shell command; the output will be returned (i.e., it won't simply be dumped to output; it can be assigned to a variable). Use of the backtick operator is identical to shell_exec().
**Example: $output = `ls -al`;
*[http://us.php.net/manual/en/function.exec.php exec]
**Description: exec — Execute an external program
**Syntax: string exec ( string $command [, array &$output [, int &$return_var]] )
**Return Values: The last line from the result of the command. If you need to execute a command and have all the data from the command passed directly back without any interference, use the passthru() function.
**Example: echo exec('whoami');
*[http://us.php.net/manual/en/function.system.php system]
**Description: system — Execute an external program and display the output
**Syntax: string system ( string $command [, int &$return_var] )
**Return Values: Returns the last line of the command output on success, and FALSE on failure.
**Example: $last_line = system('ls', $retval);
*[http://us.php.net/manual/en/function.passthru.php passthru]
**Description: passthru — Execute an external program and display raw output
**Syntax: void passthru ( string $command [, int &$return_var] )
**Return Values: No value is returned.
*[http://us.php.net/manual/en/function.shell-exec.php shell_exec]
**Description: shell_exec — Execute command via shell and return the complete output as a string
**Return Values: The output from the executed command.
**Example: $output = shell_exec('ls -lart');

==Crypt and MD5==

===Crypt===
[http://us.php.net/manual/en/function.crypt.php crypt()]
$secret = "password";
$crypt_secret = crypt($secret);
$salt = substr($crypt_secret, 0, 2);
...
$user_input = $_POST["password"]
if( crypt( $user_input, $salt ) == $crypt_secret )
echo "correct password";
# or
if( crypt( $user_input, $crypt_secret ) == $crypt_secret )
echo "correct password";

===MD5===
[http://us.php.net/manual/en/function.md5.php md5()]
$secret = "password";
$hash = md5($secret);
...
if( md5($user_input) == $hash )
echo "correct password";

==Command Line PHP==
[http://www.php.net/features.commandline PHP.net: Using PHP from the command line]

Arguments:
*As of PHP 4.3.0, the PHP variables $argc and $argv are registered and filled in with the appropriate values when using the CLI SAPI.
$argc - count of arguments
$argv[] - arguments array

STDIN:
$stdin = fopen('php://stdin', 'r');
STDOUT:
$stdout = fopen('php://stdout', 'w');
STDERR:
$stderr = fopen('php://stderr', 'w');
*You do not need to explicitly close these streams, as they are closed automatically by PHP when your script ends.

File Header:
#!/usr/bin/php

==Optimizing PHP==
*[http://phplens.com/lens/php-book/optimizing-debugging-php.php A HOWTO on Optimizing PHP]
*[http://www.sitepoint.com/blogs/2004/02/06/lazy-php-part-1/ Lazy PHP: Part 1]

*[http://dealnews.com/developers/memcached.html Fastest languages for memcached]

==PHP vs Python vs Perl==
*[http://www.sitepoint.com/blogs/2007/03/18/the-real-difference-between-php-and-python/ The real difference between PHP and Python]
*[http://wiki.w4py.org/python-vs-php.html Python vs. PHP]
*[http://lists.danga.com/pipermail/memcached/2006-June/002380.html PHP vs. Python vs. Perl]
*[http://dealnews.com/developers/memcached.html Fastest languages for memcached]
*[http://www.userscape.com/blog/index.php/site/comments/python_vs_php/ Python vs PHP]
*[http://blog.taragana.com/index.php/archive/java-versus-php-versus-python-versus-ruby-job-comparison/ Java versus PHP versus Python versus Ruby - Job Comparison]
*[http://mail.python.org/pipermail/python-list/2001-January/066996.html Python vs Ruby]
*[http://mail.python.org/pipermail/python-list/2004-December/298238.html PHP vs. Python]

==PHP Frameworks==
See [[PHP Frameworks]]

== HTTP Authentication ==

[http://us3.php.net/features.http-auth PHP: HTTP authentication with PHP - Manual]

Example #1 Basic HTTP Authentication example:
<pre>
<?php
if (!isset($_SERVER['PHP_AUTH_USER'])) {
header('WWW-Authenticate: Basic realm="My Realm"');
header('HTTP/1.0 401 Unauthorized');
echo 'Text to send if user hits Cancel button';
exit;
} else {
echo "<p>Hello {$_SERVER['PHP_AUTH_USER']}.</p>";
echo "<p>You entered {$_SERVER['PHP_AUTH_PW']} as your password.</p>";
}
?>
</pre>

Example #2 Digest HTTP Authentication example
* See http://us3.php.net/features.http-auth

== HTTP Redirect ==

<pre>
<?php
header('Location: http://www.google.com/');
?>
</pre>

Over the top:
<pre>
<?php
header('HTTP/1.1 301 Moved Permanently');
header('Location: http://www.google.com/');
?>
<html>
<head>
<meta http-equiv="REFRESH" content="0; url=http://www.google.com/" />
<body>
<p>Please follow <a href="http://www.google.com/">this link</a>.</p>
</body>
</html>
</pre>

== Logging to Apache ==

[http://us2.php.net/manual/en/function.error-log.php PHP: error_log - Manual]
error_log("Oracle database not available!");

== Backtrace ==

Similar to Java's Stack Trace:

[http://us2.php.net/manual/en/function.debug-backtrace.php PHP: debug_backtrace - Manual]
var_dump(debug_backtrace());

== Here Document ==

[http://www.php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc PHP heredoc]:
<pre>
$xmlstr = <<<XML
<?xml version='1.0' standalone='yes'?>
<movies>
<movie name="joe">
<title>PHP: Behind the Parser</title>
</movie>
</movies>
XML;
</pre>

== xml ==

[http://www.php.net/manual/en/book.simplexml.php PHP: SimpleXML - Manual]

[http://www.php.net/manual/en/class.simplexmlelement.php PHP: SimpleXMLElement - Manual]

Example:
<pre>
<?php

$xmlstr = <<<XML
<?xml version='1.0' standalone='yes'?>
<movies>
<movie name="joe">
<title>PHP: Behind the Parser</title>
<characters>
<character>
<name>Ms. Coder</name>
<actor>Onlivia Actora</actor>
</character>
<character>
<name>Mr. Coder</name>
<actor>El ActÓr</actor>
</character>
</characters>
<plot>
So, this language. It's like, a programming language. Or is it a
scripting language? All is revealed in this thrilling horror spoof
of a documentary.
</plot>
<great-lines>
<line>PHP solves all my web problems</line>
</great-lines>
<rating type="thumbs">7</rating>
<rating type="stars">5</rating>
</movie>
</movies>
XML;

$xml = new SimpleXMLElement($xmlstr);

// or
//if(!$xml=simplexml_load_file('users.xml')){
// trigger_error('Error reading XML file',E_USER_ERROR);
//}

function dospecial($xml) {
// Example of printing entity value
if ($xml->getName() == "line") {
// method #1
echo "::Value: " . $xml . "\n\n";
}
if ($xml->getName() == "character") {
// method #2
echo "::Value:(name) " . $xml->name . "\n\n";
}
// Example of printing entity attribute
if ($xml->getName() == "rating") {
// method #1
echo "::Attribute:(type) " . $xml["type"] . "\n\n";
// method #2
foreach($xml->attributes() as $name => $value) {
echo "::Attribute:(" . $name . ") " . $value . "\n\n";
}
}
}

// Walk the XML tree
function nav($xml, $space) {
$space .= " - ";
echo $space . $xml->getName() . "\n\n";
dospecial($xml);
foreach ($xml->children() as $node) {
nav($node, $space);
}
}

$space="";
echo "<pre>";
nav($xml, $space);
echo "</pre>";
</pre>

== Flush Buffer to Browser ==

httpd.conf:
<pre>
DocumentRoot /www/admin
<Directory />
AllowOverride All
</Directory>
</pre>

.htaccess:
<pre>
php_value output_buffering "0"
</pre>

code.php:
<pre>
ob_start();

echo str_pad('Loading... ',4096)."<br />\n";

for($i=0;$i<70;$i++)
{
echo 'printing...<br />';
ob_flush();
flush();

usleep(3000000);
}
?>
</pre>

References: [http://php.net/manual/en/function.ob-flush.php PHP: ob_flush - Manual]

== Windows IIS Installation ==

# Install IIS
# Install FastCGI for IIS:
** http://www.iis.net/download/fastcgi
# Install PHP (Select IIS FastCGI)

== PHP Lint ==

Syntax check only (lint):
php -l script.php

== Minimal HTTP Header Signature ==

/etc/php.ini
expose_php = Off

References:
* Hide Apache ServerSignature/ServerTokens/PHP X-Powered-By - http://www.if-not-true-then-false.com/2009/howto-hide-and-modify-apache-server-information-serversignature-and-servertokens-and-hide-php-version-x-powered-by/

== GD ==

Install:
yum install php-gd gd

Test:
php -r 'print_r(gd_info());'

== Issues ==

Error:
PHP Warning: POST Content-Length of [N] bytes exceeds the limit of [N] bytes in Unknown on line 0

Solution: (php.ini)
memory_limit = 128M
post_max_size = 3M
upload_max_filesize = 500K

References:
* PHP Warning: POST Content-Length of n bytes exceeds the limit of 3145728 bytes in Unknown on line 0 - Stack Overflow - http://stackoverflow.com/questions/11738949/php-warning-post-content-length-of-n-bytes-exceeds-the-limit-of-3145728-bytes-i

== keywords ==

[[Category:PHP]]
[[Category:Programming]]
[[Category:Web Development ]]

← Older revision		Revision as of 08:25, 5 January 2026
Line 799:		Line 799:
	[http://us2.php.net/manual/en/function.error-log.php PHP: error_log - Manual]		[http://us2.php.net/manual/en/function.error-log.php PHP: error_log - Manual]
	error_log("Oracle database not available!");		error_log("Oracle database not available!");

			== Dump Variable ==

			Display Contents of variable or Array:
			var_dump($my_var_or_array);

	== Backtrace ==		== Backtrace ==

PHP - Revision history

Kenneth: /* Backtrace */

Kenneth: /* MySQL */