Let’s talk in depth about php environment error logs

PHP is a widely used scripting language for developing dynamic websites, which means that the running environment of PHP on the web server is very important, but even the most perfect environment may have errors. At this time we The PHP error log is required to find and resolve errors.

What is PHP error log?

The PHP error log is a file that records errors that occur during PHP operation. When an error occurs during PHP operation, the error information will be written to the error log. Detailed information about errors including error type, time and date, which file made the error, error message and line of code, etc. are saved in the PHP error log.

How to enable PHP error log?

Enabling PHP error logging is very simple. In the php.ini file, find the following options:

; log_errors = Off

Set log_errors to On to enable the PHP error logging function.

Next, configure the saving path and name of the error log:

error_log = "/var/log/php_error.log"

Set error_log to the saving path and name of the error log file. The example here is to save the error log to /var/ log/php_error.log file. Make sure PHP has permission to write to the specified log file.

When an error occurs in PHP, a new error log record will be automatically added to the log file.

How to read PHP error log?

When an error occurs in PHP, the error log file will record error information. Typically, error log files can be viewed on the web server. The specific viewing method is as follows:

1. Open the console of the web server;
2. Enter the directory where the PHP error log file on the web server is located;
3. Use a text editor to open the error log file ;
4. Check the error message and resolve the error.

It is worth noting that the PHP error log may contain a lot of error information, which needs to be viewed and analyzed one by one.

Common Error Types in PHP Error Logs

There are many error types that may cause PHP error logs. The following are some of the more common error types:

1. Syntax errors

Syntax errors are the most common type of PHP errors. This type of error is triggered when the PHP code contains content that does not comply with the syntax rules. For example, a semicolon is missing, the brackets do not match, or there is an extra blank after the statement, etc.

2. Undefined constant

This error will be triggered when an undefined constant is accessed. This error usually causes the program to not run properly.

3. Undefined variables

This error will occur if undefined variables are used in PHP code.

4. Calling an undefined function

This error will be triggered when a function that does not exist is called. This error usually occurs because the function name is misspelled or the function does not exist.

How to avoid PHP errors?

1. Conduct rigorous testing on the code. Use automated testing to ensure the code runs properly in different environments.

2. Explicitly specify the type of the variable. PHP is a weakly typed language, and developers need to use correct types to ensure code readability and maintainability. Declaring variable types also helps prevent variables from being misused in statements.

3. Use the latest version of PHP for best performance and ease of use.

4. Conduct code audit and security testing. Make sure the code cannot be hacked.

Summary

PHP error log is one of the necessary tools for PHP developers. Use error logs to quickly locate and solve problems and errors in PHP code. When an error occurs in PHP, developers can find exception information through the error log file, locate the problem, and handle it promptly and effectively without affecting the performance of the website.

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