Is it possible to add a removed/deprecated function to PHP5? Like session_is_registered, ereg, etc.
[update] solved for session_is_registered:
<?php
function session_is_registered($name) {
return isset($_SESSION[$name]);
}
thanks.
Of course you can do it by modifying and recompiling the PHP source code, however the first question you have to answer is Do I really need to this or I might be better to go for my IDE's find-and-replace function?
If there is a real need for this -- for whatever reason, maybe you can redefine those functions. I haven't test it yet, as I agree with others that functions and features get removed or deprecated for a good and mostly important reasons, so I'm not sure if it does work in a situation that the function is removed or depreciated, but you can try to redefine them either using runkit_function_redefine or
override_function.
In that case you have to simulate the functionality again -- probably with their good-to-go replacements, so again think twice before start doing that.
I have a php script. I want to check the php version compatibility that each function of this script has.
For example the script has the hash() function. If we look at php.net site it says that this function was added (PHP 5 >= 5.1.2, PECL hash >= 1.1).
So assuming that this script has only this function we say that it is compatible with php 5.1.2 and onwards. Is there any software tool that can scan the script and tell you the changelog of every function and possibly gives you the lowest possible score e.g. (php version 4.3 and on)? It is a bit tedious to check manually every function in the script.
Thank you in advance
As PHP supports dynamic function/method names, just searching through the source code would not give reliable results.
Example:
$function = 'strpos';
$result = $function(...);
You might use xdebug function traces together with a 100% test coverage. This could give you all function names which had been called during a test suite run with 100% coverage - meaning all code has run. But even this isn't reliable as you would have to make sure, that your test suite covered all possible dynamic function names what is impossible. (assuming the max length of a function name is unlimited)
My final answer is: this isn't reliably possible.
First off, this is an exact duplicate of these four questions:
Highlight the difference between two strings in PHP
JavaScript based diff utility
How to do text DIFF using PHP?
Calculate text diffs in PHP
It seems as though times have changed since these questions were first asked and I am wondering what is a good tool now-a-days for this sort of comparison? I have looked at (additionally to those questions):
https://github.com/nuxodin/diff_match_patch-php
http://pear.php.net/package/Text_Diff
https://github.com/paulgb/simplediff/blob/5bfe1d2a8f967c7901ace50f04ac2d9308ed3169/simplediff.php
http://www.raymondhill.net/finediff/viewdiff-ex.php
But all of the ones I get are either unmantained now or seem a little dodgy in that they are not used that much (and some even hint that they are not very performant) and the PEAR one worries me. I hate to install PEAR for one little module not only that but it seems like throwing a brick through my own window to install it for such a small module in comparison to PEAR in general not only that but the module has been superseded and placed on a different channel (dunno why?). I would use the PEAR version if it is my only choice but I want to use the upto date package.
Does anyone know of a well used and currently maintained or built in function (even if it is a PHP extension) text diff for PHP and/or JavaScript (JQuery as well)?
Ok so it has been a while.
I actually decided to look around at what other people use and stumbled upon what Yii ( http://www.yiiframework.com ) uses.
They actually use the PEAR module for their text_diff and they use it in its new form on the horde channel. It seems that text_diff is now a horde project but you can just as easily integrate a version of it into your application and that is what Yii does by default (it comes pre-bundled with a version of it).
So I searched around a bit to find out how they used it and how to get into it and I came across:
public function actionDiff()
{
Yii::import('gii.components.TextDiff');
$model=$this->prepare();
if(isset($_GET['id']) && isset($model->files[$_GET['id']]))
{
$file=$model->files[$_GET['id']];
if(!in_array($file->type,array('php', 'txt','js','css')))
$diff=false;
elseif($file->operation===CCodeFile::OP_OVERWRITE)
$diff=TextDiff::compare(file_get_contents($file->path), $file->content);
else
$diff='';
$this->renderPartial('/common/diff',array(
'file'=>$file,
'diff'=>$diff,
));
}
else
throw new CHttpException(404,'Unable to find the code you requested.');
}
In CCodeGenerator for their Gii module ( http://www.yiiframework.com/doc/api/1.1/CCodeGenerator/ ). The important part is where they actually hook into the PEAR module:
$diff=TextDiff::compare(file_get_contents($file->path), $file->content);
By reading in the contents of two files which produces a diffed output.
Originally I did not want to use PEAR because of the bloat but this module is quite slim for a fully featured text_diff so I have decided to go with this. Not only that but, at the moment, it is the only text_diff module that has truly worked for me so I am keeping with the best, even if the best is quite memory hungry.
Have you tried one of Philippe's two solutions on this thread?
Quoted here:
In PHP. array_diff compares the first against the second array and
returns the difference.
$a1 = str_split('abcdefghijklmnop');
$a2 = str_split('abcdefghi');
echo join('', array_diff($a1, $a2)); // jklmnop
This will work as well:
$s1 = 'abcdefghijklmnop';
$s2 = 'abcdefghi';
echo str_replace(str_split($s2), '', $s1); // jklmnop
This could handle $s2 = 'ghiabcdef'; as well because str_replace() is fed with an
array, not a string.
Is there a way to remove function alias in PHP?
I can rename my function but it would be nice to use name "fetch".
Problem:
I just tested the following code and it appears to work for me, but perhaps it is because I don't have the mysqli library installed. I would test it because it might be more contextual than your IDE will have you believe. It seems to be a method for mysqli, but it might not be a global function.
<?php
function fetch(){
echo 'Hello world!';
}
fetch();
No.
(Short of recompiling the PHP binary)
This is more of a function of the IDE than the actual language... Some IDEs may give you that ability... I don't even know if recompiling the PHP binary (as Alan Storm suggested) would help since sometimes the stuff is hardcoded into the IDE / use the PHP docs online
For completeness sake: Normally, no, this can not be done. However: this can be done using a PECL extension called "runkit".
Runkit is described as "For all those things you probably shouldn't have been doing anyway", and allows you to basically tear out the innards of PHP from within PHP itself. Replacing built-in functions, undefining constants, unloading classes - suddenly everything is possible. And you should really question what you are doing if you ever feel you need it - odds are what you are doing violates some principles that are there for very good reasons, you just don't know them yet. I've never found a situation where using Runkit was a genuinely Good Idea.
Oh, in order to remove built-in functions you'll specifically need to enable this capability in your php.ini
(have fun!)
I'm looking to improve my PHP coding and am wondering what PHP-specific techniques other programmers use to improve productivity or workaround PHP limitations.
Some examples:
Class naming convention to handle namespaces: Part1_Part2_ClassName maps to file Part1/Part2/ClassName.php
if ( count($arrayName) ) // handles $arrayName being unset or empty
Variable function names, e.g. $func = 'foo'; $func($bar); // calls foo($bar);
Ultimately, you'll get the most out of PHP first by learning generally good programming practices, before focusing on anything PHP-specific. Having said that...
Apply liberally for fun and profit:
Iterators in foreach loops. There's almost never a wrong time.
Design around class autoloading. Use spl_autoload_register(), not __autoload(). For bonus points, have it scan a directory tree recursively, then feel free to reorganize your classes into a more logical directory structure.
Typehint everywhere. Use assertions for scalars.
function f(SomeClass $x, array $y, $z) {
assert(is_bool($z))
}
Output something other than HTML.
header('Content-type: text/xml'); // or text/css, application/pdf, or...
Learn to use exceptions. Write an error handler that converts errors into exceptions.
Replace your define() global constants with class constants.
Replace your Unix timestamps with a proper Date class.
In long functions, unset() variables when you're done with them.
Use with guilty pleasure:
Loop over an object's data members like an array. Feel guilty that they aren't declared private. This isn't some heathen language like Python or Lisp.
Use output buffers for assembling long strings.
ob_start();
echo "whatever\n";
debug_print_backtrace();
$s = ob_get_clean();
Avoid unless absolutely necessary, and probably not even then, unless you really hate maintenance programmers, and yourself:
Magic methods (__get, __set, __call)
extract()
Structured arrays -- use an object
My experience with PHP has taught me a few things. To name a few:
Always output errors. These are the first two lines of my typical project (in development mode):
ini_set('display_errors', '1');
error_reporting(E_ALL);
Never use automagic. Stuff like autoLoad may bite you in the future.
Always require dependent classes using require_once. That way you can be sure you'll have your dependencies straight.
Use if(isset($array[$key])) instead of if($array[$key]). The second will raise a warning if the key isn't defined.
When defining variables (even with for cycles) give them verbose names ($listIndex instead of $j)
Comment, comment, comment. If a particular snippet of code doesn't seem obvious, leave a comment. Later on you might need to review it and might not remember what it's purpose is.
Other than that, class, function and variable naming conventions are up to you and your team. Lately I've been using Zend Framework's naming conventions because they feel right to me.
Also, and when in development mode, I set an error handler that will output an error page at the slightest error (even warnings), giving me the full backtrace.
Fortunately, namespaces are in 5.3 and 6. I would highly recommend against using the Path_To_ClassName idiom. It makes messy code, and you can never change your library structure... ever.
The SPL's autoload is great. If you're organized, it can save you the typical 20-line block of includes and requires at the top of every file. You can also change things around in your code library, and as long as PHP can include from those directories, nothing breaks.
Make liberal use of === over ==. For instance:
if (array_search('needle',$array) == false) {
// it's not there, i think...
}
will give a false negative if 'needle' is at key zero. Instead:
if (array_search('needle',$array) === false) {
// it's not there!
}
will always be accurate.
See this question: Hidden Features of PHP. It has a lot of really useful PHP tips, the best of which have bubbled up to the top of the list.
There are a few things I do in PHP that tend to be PHP-specific.
Assemble strings with an array.
A lot of string manipulation is expensive in PHP, so I tend to write algorithms that reduce the discrete number of string manipulations I do. The classic example is building a string with a loop. Start with an array(), instead, and do array concatenation in the loop. Then implode() it at the end. (This also neatly solves the trailing-comma problem.)
Array constants are nifty for implementing named parameters to functions.
Enable NOTICE, and if you realy want to STRICT error reporting. It prevents a lot of errors and code smell: ini_set('display_errors', 1); error_reporting(E_ALL && $_STRICT);
Stay away from global variables
Keep as many functions as possible short. It reads easier, and is easy to maintain. Some people say that you should be able to see the whole function on your screen, or, at least, that the beginning and end curly brackets of loops and structures in the function should both be on your screen
Don't trust user input!
I've been developing with PHP (and MySQL) for the last 5 years. Most recently I started using a framework (Zend) with a solid javascript library (Dojo) and it's changed the way I work forever (in a good way, I think).
The thing that made me think of this was your first bullet: Zend framework does exactly this as it's standard way of accessing 'controllers' and 'actions'.
In terms of encapsulating and abstracting issues with different databases, Zend_Db this very well. Dojo does an excellent job of ironing out javascript inconsistencies between different browsers.
Overall, it's worth getting into good OOP techniques and using (and READING ABOUT!) frameworks has been a very hands-on way of getting to understand OOP issues.
For some standalone tools worth using, see also:
Smarty (template engine)
ADODB (database access abstraction)
Declare variables before using them!
Get to know the different types and the === operator, it's essential for some functions like strpos() and you'll start to use return false yourself.