Rewind pointer locating problems

Rewind pointer to locate the problem! It seems that the rewind pointer has an error. what is the problem? The code is as follows: & nbsp; $ fpstr = fopen (& quot; php: // input & quot;, & quot; rb & quot ;);... slightly $ bin = fread ($ fpstr, 2); // read-only 2 bytes... locate the problem with the rewind pointer!
It seems that the rewind pointer has an error. what is the problem?
The code is as follows:
$ Fpstr = fopen ("php: // input", "rb ");
...
$ Bin = fread ($ fpstr, 2); // read-only 2 bytes
...
Fseek ($ fpstr, 0); // error reported here

// Use $ fpstr Resource again
$ RealSize = stream_copy_to_stream ($ fpstr, $ tmp); // at this time, the newly created file is missing two bytes.

How to locate the pointer to the beginning of $ fpstr to complete the file.

------ Solution --------------------
$ Fpstr = fopen ("php: // input", "rb ");

Php: // input is the input stream
You cannot locate the stream.