dio_read

(PHP 4 >= 4.2.0, PHP 5 <= 5.0.5, PHP 7)

dio_read — Reads bytes from a file descriptor

说明

string dio_read ( resource $fd [, int $len = 1024 ] )

The function dio_read() reads and returns len bytes from file with descriptor fd.

参数

fd: The file descriptor returned by dio_open().
len: The number of bytes to read. If not specified, dio_read() reads 1K sized block.

返回值

The bytes read from fd.

参见

dio_write() - Writes data to fd with optional truncation at length

User Contributed Notes

alban 29-Jun-2009 02:58


I am using dio functions on windows to read RS232 port.

I can read/write but it seems that the write function cannot be binary.



In particular: 

dio_write($com1,chr(10),1); will result in writing 2 bytes 0D 0A be cause \n is translated to \r\n. I have not found any way to overcome this limitation so far

matt at vhub dot com 19-May-2006 04:48


Note that dio_read on Windows (other platforms unknown) will not timeout if there is no data to read. There is no way to specify a timeout or do a non-blocking read on Windows.