What is the function of the php readfile function?

The readfile function in PHP is used to read a file and output it to the output buffer. Its purpose is to quickly and easily output the contents of a file to the browser or command line, typically used for displaying images, text files, etc. Its syntax is as follows:

readfile(filename)

The ‘filename’ parameter specifies the path of the file to be read. By calling this function, the file content will be directly outputted without any additional read or output steps required.