Binary I/O
fread( buf, size, numItems, fp )
fwrite( buf, size, numItems, fp )
Examples:
fread( readBuf, sizeof( char ), 80, stdin );
fwrite( writeBuf, sizeof(struct utmpx), 1, fp );
Returns number of successful items read or written
rewind(fp); fseek(fp, offset, kind); ftell(fp);