What are the reasons for php escaping?

When developing web applications, security has always been an issue that developers have to pay attention to. Because if there are vulnerabilities in the application, attackers can easily exploit these vulnerabilities to invade the application and obtain sensitive information. PHP escaping is an important way to protect applications from injection attacks.

Injection attack means that the attacker enters illegal statements or codes to operate the database, control the server, and even obtain system administrator privileges. One of the most common injection attacks is SQL injection attack. SQL injection attacks usually use user input data to construct SQL statements and change the results of database execution. For example, an attacker can easily make all results true by typing "or 1=1".

To prevent this attack, PHP provides two functions: mysqli_real_escape_string() and addslashes(), which can be used to escape special characters that will cause ambiguity in SQL queries.

mysqli_real_escape_string() function
This function can escape special characters into safe characters. For example, when making a query, if the query string entered by the user contains characters such as quotation marks, backslashes, etc., this function needs to be used to escape it.

addslashes() function
This function can escape special characters into character encoding, but only escapes some common special characters, such as single quotes, double quotes, backslashes, etc.

No matter which function is used, PHP will process special characters and escape them into safe characters or character encoding to prevent injection attacks. Therefore, when writing PHP code, you must consider security issues and try to avoid putting user-entered data directly into SQL statements. Instead, use escape functions to filter and process user-entered data.

In addition to the above measures, we can also use other security protection measures to protect web applications. For example, use regular expressions to limit the set of characters entered by users, or use ORM tools to help developers process SQL statements.

In short, although it is impossible to guarantee 100% security, by taking a series of security precautions, we can avoid the occurrence of injection attacks to the greatest extent. Therefore, PHP developers must always remain vigilant and continue to pay attention to the security of their applications to ensure that their applications always run in a safe state.

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