When a file is opened using the fopen() function, it can be read with a fread() function in PHP. This function requires 2 parameters. They must be file pointers and the length of the file in bytes. The length of the file can be determined using the filesize() function in PHP, which takes the filename as an argument and returns the size of the file in bytes. Follow these steps to read a file with PHP: Open the file using the fopen() function . Get the file length using the filesize() function. Read the contents of the file using the fread() function. Close the file using the fclose() function.