I'm developing a web page that should read and change the contents of specific files on the server.
These files will only have two values: 1 or 0. Reading/changing the contents will be made via combo boxes with OnChange. Basically the idea is to control appliances via General Purpose Input/Outputs (GPIO's). The electronics part is all done, I just need to finish the web programing part and got stuck on it.
I'm not experienced in programing at all, but with some snippets found here and there, I was able to implement part of it with AJAX/PHP.
So far, I'm able to read the values, but unable to change it even though I'm building the correct command with "escapeshellarg".
Also, I was expecting to have two interactive areas in the page but only the original is working.
Could anyone point me into the right direction? Any help/suggestion/comment will be welcomed.
pqp6.php
<html>
<head>
<script>
function showUser(str)
{
if (str=="")
{
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","getinfo.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>
<?php
$file1="/var/www/file1";
$file2="/var/www/file2";
$output = shell_exec('cat '.escapeshellarg($file1));
if($output == 0)
{
echo "zero ; ";
$file1status = "off";
$file1oposite = "on";
$file1exec= "file1on";
}
else
{
echo "one ; ";
$file1status= "on";
$file1oposite= "off";
$file1exec= "file1off";
}
echo "output:$output ; file1status:$file1status ; file1oposite:$file1oposite ; file1exec:$file1exec <br><br>";
$output = shell_exec('cat '.escapeshellarg($file2));
if($output == 0)
{
echo "zero ; ";
$file2status = "off";
$file2oposite = "on";
$file2exec= "file2on";
}
else
{
echo "one ; ";
$file2status= "on";
$file2oposite= "off";
$file2exec= "file2off";
}
echo "output:$output ; file2status:$file2status ; file2oposite:$file2oposite ; file2exec:$file2exec <br><br>";
?>
<br>
<br>
FILE 1:
<form>
<select name="file1" onchange="showUser(this.value)">
<option value="1,<?=$file1status?>"><?=$file1status?></option>
<option value="1,<?=$file1oposite?>"><?=$file1oposite?></option>
</select>
</form>
<br>
<div id="txtHint"><b>File 1 information will be listed here.</b> </div>
<br>
<br>
FILE 2:
<form>
<select name="file2" onchange="showUser(this.value)">
<option value="2,<?=$file2status?>"><?=$file2status?></option>
<option value="2,<?=$file2oposite?>"><?=$file2oposite?></option>
</select>
</form>
<br>
<div id="txtHint"><b>File 2 information will be listed here.</b></div>
</body>
</html>
getinfo.php:
<?php
$q=$_GET["q"];
$q_stripped = explode(",", $q);
$file_n = $q_stripped[0];
$file_command = $q_stripped[1];
$path="/var/www/file";
if($file_command == "on")
{
$file_command = "1 > ";
}
else
{
$file_command = "0 > ";
}
$command= "/bin/echo $file_command$path$file_n";
$escaped_command = escapeshellarg($command);
echo "COMMAND: $escaped_command";
shell_exec($escaped_command);
echo "file_n=$file_n ; file_command=$file_command ; ";
?><?php
