How to hook PHP mail() function

There are times when you may need to hook some PHP function for one reason or another. PHP makes it an easy task to accomplish using override_function which overrides built-in functions. This is useful only in the context of your own code or the code you can easily change in order to work with the aforementioned function. So, this solution might not be always at your disposal.

Specifically, let’s take a deeper look into the PHP mail function which is frequently used and misused in various scripts.

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PHP – How to escape only single quotes?

Escaping special characters is a usual business in programming and PHP is not an exception either. There are plenty of escaping functions in PHP and we already mentioned some of them that deal with encoding HTML entities. MySQL is also picky when it comes to special characters and it has its own sets and rules which are usually covered with escaping functions such as addslashes. However, when it comes to storing JSON in the MySQL the approach is a bit different.

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Difference between htmlspecialchars_decode and html_entity_decode

There are quite a few similar functions in PHP. Some of them are almost identical like echo and print and some have subtle differences which are not obvious at the first glance. We can put htmlspecialchars_decode and html_entity_decode in this category. There is a lot of confusion between notions of HTML special characters and HTML entities so let’s look into the difference.

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PHP – Convert special character &quot to real quote

In certain situations, you could be messing with HTML special characters in a text. At first glance, you might not even notice these are existing in the text. For example, if you’re looking text in a browser these characters will look just like normal characters. But when you peak into the page source you’ll see very different representations, (&amp; for &, &quot; for “, &lt; for <, &gt for > and so on). So how do you convert it to the normal characters?

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How to copy file with SCP from one server to other without password

Sometimes we will need to automate file copying between our servers. For example, our shell script might need to copy the backup from time to time and we don’t want to provide the password in the clean text format. So what we can do about this?

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Multiple MySQL instances on one server

When you enter the field of multiple MySQL instances on one physical server you might run into the trouble. Lack of documentation, cryptic bugs, and insane settings is something you need to get used to. I almost quit a few times in the process and only my habit of trying unusual things when everything logical failed kept me up to the solution.

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Invalid characters in JSON

Recently I run into problems trying to save JSON into MySQL database. Even though MySQL supports JSON type for some time now, there are still plenty of gotchas while you work with it. The situation is pretty critical with special characters. This time we are going to be short and on the topic of invalid JSON characters.

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PHP – What is the difference between echo and print?

PHP can sometimes be confusing where it shouldn’t be. One area of confusion is the issue with duplicate built-in functions. I’m always inclined to think that developers probably had good reason to make duplicates and the most of the times its good assumption.

But is it always true? Let’s see on the example of echo end print functions.

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PHP – What is the difference between single and double quotes?

Difference between single and double quotes in PHP can be confusing. Moreover, it can lead to unexpected results, so it’s better to get familiar with it so you can avoid bugs.

Let’s dive into the details…

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