Configure php.ini to implement the php file upload function

Explanation of configuration options for the file upload function in php.ini

Use a text tool (EditPlus recommended) to open the php.ini configuration file and look for File Uploads. There are the following 3 options in this area:

file_uploads = On

Whether to allow HTTP File Upload. The default value is On to allow HTTP file uploads, this option cannot be set to Off.

upload_tmp_dir =

The temporary storage directory for file upload. If not specified, PHP will use the system's default temporary directory. This option is empty by default. This option is easy to forget when manually configuring the PHP running environment. If this option is not configured, the file upload function cannot be implemented. You must assign a value to this option, such as upload_tmp_dir = "d:/fileuploadtmp". It means that there is a fileuploadtmp directory in the D drive directory, and read and write permissions are given to this directory.

upload_max_filesize = 2M

Maximum size of uploaded files. The default value of this option is 2M, that is, the file upload size is 2M. If you want to upload a 50M file, you must set upload_max_filesize = 50M.
But just setting upload_max_filesize = 50M still cannot realize the upload function of large files. We must also modify the post_max_size option in the php.ini file.

Continue to search for Data Handling in php.ini. There is an option in this area:

post_max_size = 8M

refers to the maximum value that PHP can receive through form POST, including all values ​​in the form. The default is 8M. If the POST data exceeds the limit, $_POST and $_FILES will be empty.
To upload large files, you must set the value of this option to be greater than the value of the upload_max_filesize option. For example, if you set upload_max_filesize = 50M, you can set post_max_size = 100M.
In addition, if memory limit is enabled, the value should be smaller than the value of the memory_limit option.

Continue to look for Resource Limits in php.ini. There are 3 options in this area:

max_execution_time = 30

The maximum time value (in seconds) for each PHP page to run, the default is 30 seconds. When we upload a larger file, such as a 50M file, it is likely to take several minutes to complete. However, the default PHP page execution time is 30 seconds. If it exceeds 30 seconds, the script will stop executing, which results in an inability to When opening a web page. Therefore we can set the value larger, such as max_execution_time = 600. If set to 0, it means no time limit.

max_input_time = 60

The time (in seconds) used by each PHP script to parse the request data, the default is 60 seconds. When we upload large files, we can set this value larger. If set to 0, it means no time limit.

memory_limit = 128M

This option is used to set the maximum memory space that a single PHP script can apply for. This helps prevent poorly written scripts from eating up the available memory on the server. Set this to -1 if no memory constraints are required.
The default version of php5.2.0 is 8M; the default version of php.5.2.0 is 16M. Versions after php 5.2.0 default to 128M;

php.ini Example of configuring the upload file function

Suppose you want to upload a large file of 50M. Configure php.ini as follows:
file_uploads = On
upload_tmp_dir = "d:/fileuploadtmp"
upload_max_filesize = 50M
post_max_size = 100M
max_execution_time = 600
max_input_time = 600
memory_limit = 128M

Tips: Need to keep memory_limit > post_max_size > ; upload_max_filesize

This example is for reference only, you can adjust it according to the actual situation.