Analyze and solve the problem of php page pictures not displaying

PHP is a common server-side scripting language that can be used for website development and database connection operations. However, when developing websites using PHP, we sometimes encounter the problem that images cannot be displayed. So what causes this problem? This article will analyze this problem and provide some solutions.

Problem Description

In a PHP page, we may use code similar to the following to display an image:

<img src="example.jpg" alt="Example Image">

However, when we access the page in the browser When viewing the page, the image cannot be displayed properly. This situation usually occurs when relative paths are used to reference images in PHP programs.

Cause of the problem

There are many reasons why pictures cannot be displayed normally. The following are some common reasons and their solutions:

1. Relative path error

When referencing images in PHP, the relative path should be relative to the path of the HTML file rather than the path of the PHP file. If the PHP file and image file are not in the same directory, we need to use some additional path information in the relative path. For example, if our website file structure is as follows:

/
├── css/
├── images/
│   └── example.jpg
├── php/
│   └── example.php
└── index.html

When referencing images in example.php, the correct relative path should be:

<img src="../images/example.jpg" alt="Example Image">

where ../ means returning to the upper-level directory where the PHP file is located, that is, the root directory of the website.

2. The image file does not exist

If we use the correct relative path in the code, but the image still cannot be displayed, it is probably because the image file does not exist or the path is wrong. We can check whether the image path is correct or try to copy the image to the correct path.

3. Insufficient permissions

If the permissions of the image file are not set correctly, we will not be able to display the image normally. We can check whether the permission settings of the image file are correct on the server side. If we need to modify the permissions, we can use the chmod command to modify it.

Solution

According to the causes of the above problems, we can take some of the following measures to solve the problem of images not being displayed properly:

1. Use absolute paths

Using absolute paths to reference images can avoid problems caused by relative paths. We can set the path of the image to an absolute path, for example:

<img src="/images/example.jpg" alt="Example Image">

where / represents the root directory of the website.

2. Check file permissions

We can use the chmod command to set the permissions of the image file to readable. The specific command is as follows:

chmod 644 example.jpg

where 644 represents the permissions of the file, where 6 represents the read and write permissions of the file owner, 4 represents the read permissions of the group user, 4 Indicates read permissions for other users.

3. Check the file path

We can check on the server side whether the image file exists and whether its path is correct. We can use PHP's file_exists() function to check whether the file exists. If the function returns true, the file exists.

The above are the reasons and solutions for the problem that PHP page images cannot be displayed. We can choose a method that suits us to solve this problem according to the specific situation.

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