How to debug PHP CLI scripts

How to debug PHP CLI scripts? Use the var_dump() function to display variable contents and types. Set display_errors and log_errors to display errors and log them in the error log. Install and configure Xdebug for advanced debugging capabilities, including stack tracing and variable inspection.

How to debug PHP CLI scripts

PHP Command Line Interface (CLI) scripts can be used to perform a variety of tasks, from simple Automate scripts to complex background processing. Debugging is critical when developing or using CLI scripts to help you find and fix problems quickly.

Using var_dump()

var_dump() The function is a useful debugging tool that can display a variable content, type and structure. Insert var_dump() in the suspect area and run the script to see the output. For example:

<?php
$array = ['foo', 'bar', 'baz'];

var_dump($array);
?>

This will output:

array(3) {
  [0]=>
  string(3) "foo"
  [1]=>
  string(3) "bar"
  [2]=>
  string(3) "baz"
}

Settings display_errors and log_errors

in php .ini file, you can change the display_errors and log_errors settings to enable error display and logging:

display_errors = On
log_errors = On

This will ensure that errors are displayed directly in the output and logged in the error log file.

Using Xdebug

Xdebug is a popular PHP debugging extension that provides a wide range of debugging capabilities, including stack tracing, variable inspection, and performance analysis. To install Xdebug, follow the instructions in its official documentation.

Practical Case

Let us consider a script to import data from a CSV file into a database:

<?php
$csv = fopen('data.csv', 'r');
while (($data = fgetcsv($csv)) !== FALSE) {
  // 导入数据库
}
fclose($csv);
?>

Suppose you encounter an error, data Unable to import database.

1. Add var_dump(): Add var_dump($data) before importing the database to check the read data.
2. Check the error log: Open the php.ini file and make sure display_errors and log_errors are enabled. Check the error log to identify any error messages.
3. Using Xdebug: Install and configure Xdebug. Set a breakpoint and run the script before importing the data. You can check variable values ​​and step through the code line by line to find the problem.

By using these techniques, you can quickly and efficiently debug PHP CLI scripts to ensure they run correctly.

The above is the detailed content of How to debug PHP CLI scripts. For more information, please follow other related articles on the PHP Chinese website!