I am looking for a way to communicate with RS232 serial COM port on windows. I have found 2 solutions on the net, one which is not totally free (introduces deliberate delays on the function) and another with limited capability on Windows. The latter can only write to a COM port on Windows, not read.
I can't look at the code of the first solution since it is compiled into a .dll (makes sense, otherwise people can just edit the delay and not purchase it...) and the second one seems only to use fopen() to open the port and later fwrite() to it for writing, just like one would do to a stream. But apparently freading it returns nothing.
I know it's possible as the first solution did it, although it does require Apache to use php-cgi module instead of php5module.
Every solution above is either inefficient or too much work.
You can just use the PHP-DIO library (dio_fcntl, dio_open, dio_read, dio_write, dio_seek, ...). It's also in the PHP manual's entry for DIO:
This PECL package isn't available by default. To get it for Windows if you have PHP 5.2.x greater than 5.2.6, you can download it as part of a ZIP:
Thread-safe (for Apache)
Non-thread-safe (for IIS)
Both of these links were found in http://www.deveblog.com/index.php/download-pecl-extensions-for-windows/
Here is the build from Linux, just get it and do the phpize/configure/make/make install thing.
I don't know whether it should be used in an Apache session, but go for it.