fread() reads up to
length bytes from the file pointer
handle. Reading stops when up to
length bytes have been read, EOF
(end of file) is reached, (for network streams) when a packet becomes
available, or (after opening userspace stream) when 8192 bytes have been read
whichever comes first.
Returns the read string or FALSE in case of error.
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 anything that is not a regular local file, such as streams returned when reading remote files or from popen() and fsockopen(), reading will stop after a packet is available. This means that you should collect the data together in chunks as shown in the examples below.
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.