fread() reads up to length bytes from the file pointer referenced by handle. Reading stops when length bytes have been read, EOF (end of file) is reached, or (for network streams) when a packet becomes available, whichever comes first.
On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen() mode parameter.
When reading from network streams or pipes, such as those returned when reading remote files or from popen() and proc_open(), reading will stop after a packet is available. This means that you should collect the data together in chunks as shown in the example below.
Note: The example above has better performance than the traditional approach using while(!feof()), as we are saving the overhead of a function call per iteration.
Note: If you just want to get the contents of a file into a string, use file_get_contents() as it has much better performance than the code above.