Increment of variable won't work

realWasabi · May 2, 2013

Hi.

I have a script, where I want it to refresh a page if it meets certain requirements. It have a 'increment'-function so it stops after 10 refreshes or when it meets a certain requirement whichever comes first.

I can get it to refresh just fine, but the increment won't work. It just stays on '1' tries.

And yes, I use globals - and there's probably other very bad things in there, but I'm a beginner, please don't flame me for that. I'll make something that works, and then can I start to learn to beautify it

Besides that - what am I doing wrong?

This is the part of my code that refreshes (boiled down to only relevant code):

$maxtries = "10";
$timeout    = "2";
$ip = $_GET["ip"];
$pageurl = pageurl();



function pageurl( ) {
$pageurl = "HTTP";
if ( $_SERVER[ "HTTPS" ] == "on" ) {
$pageurl .= "S";
}
$pageurl .= "://";
if ( $_SERVER[ "SERVER_PORT" ] != "80" ) {
$pageurl .= $_SERVER[ "SERVER_NAME" ] . ":" . $_SERVER[ "SERVER_PORT" ] . $_SERVER[ "REQUEST_URI" ];
} else {
 $pageurl .= $_SERVER[ "SERVER_NAME" ] . $_SERVER[ "REQUEST_URI" ];
}
$urlarts = explode( "?", $pageurl );
$pageurl = $urlarts[ "0" ];
return $pageurl;
}


function htmlheader( ) {
global $tries, $maxtries, $pageurl, $timeout;
if ($tries < $maxtries - 1 ) {
$tries = $tries + 1;
}
$content = "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?ip=10.0.0.14?&tries=$tries\">\n";
return $content;
}

...
else if ($stdout == 0) {
echo '<p style="color:red;">link down</p>';
echo htmlheader();

And this is the whole script:

<?php
$descriptorspec = array(
0 => array("pipe", "r"),    // stdin is a pipe that the child will read from
1 => array("pipe", "w"),    // stdout is a pipe that the child will write to
2 => array("pipe", "w")     // stderr is a pipe that the child will write to
);
$maxtries = "10";
$timeout    = "2";
$ip = $_GET["ip"];
$pageurl = pageurl();


function pageurl( ) {
$pageurl = "HTTP";
if ( $_SERVER[ "HTTPS" ] == "on" ) {
$pageurl .= "S";
}
$pageurl .= "://";
if ( $_SERVER[ "SERVER_PORT" ] != "80" ) {
$pageurl .= $_SERVER[ "SERVER_NAME" ] . ":" . $_SERVER[ "SERVER_PORT" ] . $_SERVER[ "REQUEST_URI" ];
} else {
 $pageurl .= $_SERVER[ "SERVER_NAME" ] . $_SERVER[ "REQUEST_URI" ];
}
$urlarts = explode( "?", $pageurl );
$pageurl = $urlarts[ "0" ];
return $pageurl;
}


function htmlheader( ) {
global $tries, $maxtries, $pageurl, $timeout;
if ($tries < $maxtries - 1 ) {
$tries = $tries + 1;
}
$content = "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?ip=10.0.0.14?&tries=$tries\">\n";
return $content;
}


if ($ip == NULL) { 
echo "error";
}
else {
$cmd = "/share/MD0_DATA/scripts/./webping $ip";
$process = proc_open($cmd, $descriptorspec, $pipes);
if (is_resource($process)) {
    $stdin = stream_get_contents($pipes[0]);
    $stdout = stream_get_contents($pipes[1]);
    $stderr = stream_get_contents($pipes[2]);
    fclose($pipes[0]);  fclose($pipes[1]);  fclose($pipes[2]);
    // It is important that you close any pipes before calling proc_close in order to avoid a deadlock
    $return_value = proc_close($process);   
}
if ($stdout == 2) {
echo '<p style="color:green;">link up</p>';
}
else if ($stdout == 1) {
echo '<p style="color:yellow;">link up (warning)</p>';
}
else if ($stdout == 0) {
echo '<p style="color:red;">link down</p>';
echo htmlheader();
}
else {
echo 'error (no IP specified?)';
}
}
?>

Jessica · May 2, 2013

Try making your max tries a number instead of a string, and defining $tries.

realWasabi · May 2, 2013

I tried adding $tries = "1" and changed if ($tries < 10 - 1) but that didn't work.

Any other suggestions?

PaulRyan · May 2, 2013

Jessica said "number instead of a string".

This mean $tries = 1; NOT $tries = "1";

Any variable that is a number, you do not need any quotes around.

realWasabi · May 2, 2013

Jessica said "number instead of a string".

This mean $tries = 1; NOT $tries = "1";

Any variable that is a number, you do not need any quotes around.

Neither works.

PaulRyan · May 2, 2013

Post the current code you have

realWasabi · May 2, 2013

<?php
$descriptorspec = array(
0 => array("pipe", "r"),    // stdin is a pipe that the child will read from
1 => array("pipe", "w"),    // stdout is a pipe that the child will write to
2 => array("pipe", "w")     // stderr is a pipe that the child will write to
);
$maxtries = 10;
$timeout = 2;
$ip = $_GET["ip"];
$pageurl = pageurl();
$tries = 1;


function pageurl( ) {
$pageurl = "HTTP";
if ( $_SERVER[ "HTTPS" ] == "on" ) {
$pageurl .= "S";
}
$pageurl .= "://";
if ( $_SERVER[ "SERVER_PORT" ] != "80" ) {
$pageurl .= $_SERVER[ "SERVER_NAME" ] . ":" . $_SERVER[ "SERVER_PORT" ] . $_SERVER[ "REQUEST_URI" ];
} else {
 $pageurl .= $_SERVER[ "SERVER_NAME" ] . $_SERVER[ "REQUEST_URI" ];
}
$urlarts = explode( "?", $pageurl );
$pageurl = $urlarts[ "0" ];
return $pageurl;
}


function htmlheader( ) {
global $tries, $maxtries, $pageurl, $timeout;
if ($tries < $maxtries - 1 ) {
$tries = $tries + 1;
}
$content = "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?ip=10.0.0.14?&tries=$tries\">\n";
return $content;
}


if ($ip == NULL) { 
echo "error";
}
else {
$cmd = "/share/MD0_DATA/scripts/./webping $ip";
$process = proc_open($cmd, $descriptorspec, $pipes);
if (is_resource($process)) {
    $stdin = stream_get_contents($pipes[0]);
    $stdout = stream_get_contents($pipes[1]);
    $stderr = stream_get_contents($pipes[2]);
    fclose($pipes[0]);  fclose($pipes[1]);  fclose($pipes[2]);
    // It is important that you close any pipes before calling proc_close in order to avoid a deadlock
    $return_value = proc_close($process);   
}
if ($stdout == 2) {
echo '<p style="color:green;">link up</p>';
}
else if ($stdout == 1) {
echo '<p style="color:yellow;">link up (warning)</p>';
}
else if ($stdout == 0) {
echo '<p style="color:red;">link down</p>';
echo htmlheader();
}
else {
echo 'error (no IP specified?)';
}
}
?>

I tried "if ($tries < 10 - 1 ) {" but that didn't work. I also tried to change the other "numbers" to "real" numbers like with the $tries variable.

kicken · May 2, 2013

Incrementing the tries variable does no good, because every time the script is run (each page load) all variables are re-initialized. Values are not carried over from page to page (so $tries always starts at 1).

In order for a variable to be maintained from page to page, you need to store it in either a session or a cookie.

realWasabi · May 2, 2013

Incrementing the tries variable does no good, because every time the script is run (each page load) all variables are re-initialized. Values are not carried over from page to page (so $tries always starts at 1).

In order for a variable to be maintained from page to page, you need to store it in either a session or a cookie.

They don't have to be carried over as the URL changes on every update and it just adds 1 to the current 'tries'. This is another, similar script which makes it work without the use of session/cookie:

<?php
$device     = "roadrunner";
// IP address of device, example "x.x.x.x".
$deviceip   = "10.0.0.14";
// TCP Port on device to check, example "3389" = RDP, "80" = WebServer.
$deviceport = "3389";
// MAC address of NIC1 on device, example "00:00:00:00:00:00" or "00-00-00-00-00-00".
$devicemac1 = "00-11-22-33-44-55";
// MAC address of NIC2 on device, example "00:00:00:00:00:00" or "00-00-00-00-00-00". - Optional set to "" if NIC2 not required.
$devicemac2 = "";
// Number of times to attempt to connect to port on device after magic packet sent, example "10"
$maxtries   = "10";
// Broadcast address of network, example ""x.x.x.x". ("255.255.255.255" works in most cases.)
$broadcast  = "255.255.255.255";
// ICMP port number, default "7".
$udport     = "7";
// Timeout value for re-tries (in seconds), default "10".
$timeout    = "2";
//
// $frame - used to determine which content to display when executed.
$frame      = "1";
// $tries - used to determine number of attempts at checking port beetween reloads, compared with maxtries.
$tries      = $_GET[ "tries" ];
// $pageurl - obtain URL used to access file, used when creating frameset & setting reloads.
$pageurl    = pageurl();
// Process variables used in frame2, increments tries & sets status to Success(1) or Failed(2)
if ( $frame == 1 ) {
               processurl();
}
// ###### Functions ######
//
// function pageurl( ) - Returns URL of page via PHP variables.
function pageurl( )
{
               $pageurl = "HTTP";
               if ( $_SERVER[ "HTTPS" ] == "on" ) {
                               $pageurl .= "S";
               }
               $pageurl .= "://";
               if ( $_SERVER[ "SERVER_PORT" ] != "80" ) {
                               $pageurl .= $_SERVER[ "SERVER_NAME" ] . ":" . $_SERVER[ "SERVER_PORT" ] . $_SERVER[ "REQUEST_URI" ];
               } else {
                               $pageurl .= $_SERVER[ "SERVER_NAME" ] . $_SERVER[ "REQUEST_URI" ];
               }
               $urlarts = explode( "?", $pageurl );
               $pageurl = $urlarts[ "0" ];
               return $pageurl;
}


//  function processurl( ) - Processes variables used in frame2, increments tries & sets status to Success(1) or Failed(2)
function processurl( )
{
               global $status, $tries, $maxtries;
               if ( $status == 0 && $tries < $maxtries - 1 ) {
                               $tries = $tries + 1;
               } else {
                               $status = 2;
               }
               if ( portcheck() == 0 ) {
                               $status = 1; 
               }
}
//  function wakeonlan() - Attempts to send WoL packet and returns outcome.
function wakeonlan( $device, $mac )
{
               global $broadcast, $udport;
               $mac            = preg_replace( "/[^A-Za-z0-9]/", ":", $mac );
               $broadcast_byte = explode( ':', $mac );
               $hw_addr        = '';
               for ( $a = 0; $a < 6; $a++ )
                               $hw_addr .= chr( hexdec( $broadcast_byte[ $a ] ) );
               $msg = chr( 255 ) . chr( 255 ) . chr( 255 ) . chr( 255 ) . chr( 255 ) . chr( 255 );
               for ( $a = 1; $a <= 16; $a++ )
                               $msg .= $hw_addr;
               $s = socket_create( AF_INET, SOCK_DGRAM, SOL_UDP );
               if ( $s == false ) {
                               $content = "Error creating socket!\n";
               } else {
                               // setting a broadcast option to socket:
                               $opt_ret = socket_set_option( $s, 1, 6, true );
                               if ( $opt_ret < 0 ) {
                                               $content = "setsockopt() failed, error: " . strerror( $opt_ret ) . "\n";
                               }
                               if ( socket_sendto( $s, $msg, strlen( $msg ), 0, $broadcast, $udport ) ) {
                                               $content = "WoL packet sent to mac address " . $mac . "...\n";
                                               socket_close( $s );
                               } else {
                                               $content = "Failed to send WoL packet!";
                               }
               }
               return $content;
}
//  function portcheck( ) - Attempts to connect to TCP port on the device via a Socket, returns $errno.
function portcheck( )
{
               global $deviceip, $deviceport;
               $file = fsockopen( $deviceip, $deviceport, $errno, $errstr, 50 );
               if ( $errno == 0 ) {
                               fclose( $file );
               }
               return $errno;
}
// function htmlheader( ) - Returns HTML Header for TITLE and if Frame2 REFRESH set.
function htmlheader( )
{
               global $device, $frame, $tries, $maxtries, $status, $pageurl, $timeout;
               // global "custom" header settings
               $content = "<TITLE>PHP WoL ($device) - by PRThomasUK </TITLE>\n";
               //generate refresh header for frame2.
               if ( $status == 0 ) {
                                $content .= "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?&tries=$tries\">\n";
               }
               return $content;
}
// function htmlheader( ) - Returns HTML content for mainpage, frame1 & frame2 based on value of $frame.
function htmlcontent( )
{
               global $pageurl, $device, $deviceip, $deviceport, $devicemac1, $devicemac2, $frame, $tries, $maxtries, $status;
               if ( $frame == 1 ) {
                               if ( $status == 0 ) {
                                $content = "<script type=\"text/javascript\">function stopFrameload() { window.stop(); document.execCommand(\"Stop\");}</script>\n";
                                               $content .= "<p>Checking connectivity... ($tries/$maxtries)   &nbsp<a href=\"\" onclick=\"stopFrameLoad(); return false;\">Stop</a></p>\n";
                               } elseif ( $status == 1 ) {
                                               $content .= "<p>SUCCESS</p>\n";
                               } else {
                                               $content .= "<p>FAILED</p>\n"; }
              } else {
                               $content = "<FRAMESET rows=\"10,*\" frameborder=0 border=0>\n";
                               $content .= "<FRAME SRC=\"$pageurl?frame=2\">\n";
                               $content .= "<NOFRAMES>\n";
                               if ( $devicemac2 ) {
                                               $content .= "<BR>\n";
                                               $content .= wakeonlan( $device, $devicemac2 );
                               }
                               $content .= "<BR>\n";
                               $content .= "<BR>\n";
                               $content .= "<FONT COLOR=\"red\">\n";
                               $content .= "<H2>Your browser does not support frames...</H2>\n";
                               $content .= "</FONT>\n";
                               $content .= "<H3>Status of $device will not be monitored!</H3>\n";
                               $content .= "</NOFRAMES>\n";
                               $content .= "</FRAMESET>\n";
              } return $content; 
}
?>


<?php
echo htmlheader(); 
echo htmlcontent(); 
?>

PaulRyan · May 2, 2013

Well $tries is carried, along with $pageurl, in the META refresh tag.

$tries needs to be something like:

$tries = isset($_GET['tries']) ? (int)$_GET['tries'] : 1 ;

realWasabi · May 2, 2013

Well $tries is carried, along with $pageurl, in the META refresh tag.

$tries needs to be something like:
$tries = isset($_GET['tries']) ? (int)$_GET['tries'] : 1 ;

Instead of the "$tries = 1;"? Or where do you mean? Because I'm a little unsure about what that string does?

PaulRyan · May 2, 2013

The above string is whats called a ternary operator (I believe)

It is short hand for an if else statement, it is equivalent to the following:

<?PHP
  if(isset($_GET['tries'])) {
    $tries = (int)$_GET['tries'];
  } else {
    $tries = 1;
  }
?>

And yes, it replaces $tries = 1;

realWasabi · May 2, 2013

Woho, it works!

Thanks to all of you, but especially PoulRyan for solving the puzzle.

I added "else { break; }" after the header if-statement so it stops refreshing after the maxtries have been reached. Also I lowered the tries-number to 0 so it actually does retry 10 times.

Just one thing - instead of specifying the IP directly in the meta line, I added the $ip variable. It works, but adds a "?" for every update. So after 10 updates, the url looks like this: http://domain.com/ping.php?ip=10.0.0.14?????????&tries=9

I can't figure out why. Any easy way around this?

Current script:

<?php
$descriptorspec = array(
0 => array("pipe", "r"),    // stdin is a pipe that the child will read from
1 => array("pipe", "w"),    // stdout is a pipe that the child will write to
2 => array("pipe", "w")     // stderr is a pipe that the child will write to
);
$maxtries = 10;
$timeout = 2;
$ip = $_GET["ip"];
$pageurl = pageurl();
$tries = isset($_GET['tries']) ? (int)$_GET['tries'] : 0 ;


function pageurl( ) {
$pageurl = "HTTP";
if ( $_SERVER[ "HTTPS" ] == "on" ) {
$pageurl .= "S";
}
$pageurl .= "://";
if ( $_SERVER[ "SERVER_PORT" ] != "80" ) {
$pageurl .= $_SERVER[ "SERVER_NAME" ] . ":" . $_SERVER[ "SERVER_PORT" ] . $_SERVER[ "REQUEST_URI" ];
} else {
 $pageurl .= $_SERVER[ "SERVER_NAME" ] . $_SERVER[ "REQUEST_URI" ];
}
$urlarts = explode( "?", $pageurl );
$pageurl = $urlarts[ "0" ];
return $pageurl;
}


function htmlheader( ) {
global $ip, $tries, $maxtries, $pageurl, $timeout;
if ($stdout == 0 && $tries < $maxtries - 1 ) {
$tries = $tries + 1;
}
else {
exit;
}
$content = "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?ip=$ip?&tries=$tries\">\n";
return $content;
}


if ($ip == NULL) { 
echo "error";
}
else {
$cmd = "/share/MD0_DATA/scripts/./webping $ip";
$process = proc_open($cmd, $descriptorspec, $pipes);
if (is_resource($process)) {
    $stdin = stream_get_contents($pipes[0]);
    $stdout = stream_get_contents($pipes[1]);
    $stderr = stream_get_contents($pipes[2]);
    fclose($pipes[0]);  fclose($pipes[1]);  fclose($pipes[2]);
    // It is important that you close any pipes before calling proc_close in order to avoid a deadlock
    $return_value = proc_close($process);   
}
if ($stdout == 2) {
echo '<p style="color:green;">link up</p>';
}
else if ($stdout == 1) {
echo '<p style="color:yellow;">link up (warning)</p>';
}
else if ($stdout == 0) {
echo '<p style="color:red;">link down</p>';
echo htmlheader();
}
else {
echo 'error (no IP specified?)';
}
}
?>

PaulRyan · May 2, 2013

You added an extra question mark after the $ip variable.

$content = "<META HTTP-EQUIV=\"refresh\" CONTENT=\"$timeout;url=$pageurl?ip=$ip&tries=$tries\">\n";

realWasabi · May 2, 2013

*facepalm*. I read through the entire code 3 times without noticing that. Thanks again

PaulRyan · May 2, 2013

No problem, if all is done, please mark as solved

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Increment of variable won't work

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