note 112243 added to function.fopen

Writing and reading on a serial port. If you are unable or unwilling to install the serial device library for PHP, its still possible to communicate through a serial port or USB device. There are two issues to note: - you must use a system call to set the port control options - you must use NON blocking stream mode for reading (not for writing unless you use flow control) <?php // Set timeout to 500 ms $timeout=microtime(true)+0.5; // Set device controle options (See man page for stty) exec("/bin/stty -F /dev/ttyS0 19200 sane raw cs8 hupcl cread clocal -echo -onlcr "); // Open serial port $fp=fopen("/dev/ttyS0","c+"); if(!$fp) die("Can't open device"); // Set blocking mode for writing stream_set_blocking($fp,1); fwrite($fp,"foo\n"); // Set non blocking mode for reading stream_set_blocking($fp,0); do{ // Try to read one character from the device $c=fgetc($fp); // Wait for data to arive if($c === false){ usleep(50000); continue; } $line.=$c; }while($c!="\n" && microtime(true)<$timeout); echo "Responce: $line"; ?> ---- Server IP: 195.184.96.15 Probable Submitter: 109.198.131.34 ---- Manual Page -- http://php.net/manual/en/function.fopen.php Edit -- https://master.php.net/note/edit/112243 Del: integrated -- https://master.php.net/note/delete/112243/integrated Del: useless -- https://master.php.net/note/delete/112243/useless Del: bad code -- https://master.php.net/note/delete/112243/bad+code Del: spam -- https://master.php.net/note/delete/112243/spam Del: non-english -- https://master.php.net/note/delete/112243/non-english Del: in docs -- https://master.php.net/note/delete/112243/in+docs Del: other reasons-- https://master.php.net/note/delete/112243 Reject -- https://master.php.net/note/reject/112243 Search -- https://master.php.net/manage/user-notes.php