PHP

PC/SC Wait for Smart Card Status Change (Inserted, Removed from Reader, etc.)

See more SCard Examples

Demonstrates how to synchronously wait for a status change, such as for a smart card to be inserted into a reader, or removed from a reader.

Note: This functionality was introduced in Chilkat v9.5.0.87.

Chilkat2 PHP

<?php

use Chilkat2\JsonObject;
use Chilkat2\SCard;
use Chilkat2\StringBuilder;
use Chilkat2\StringTable;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$scard = new SCard();

// First establish a context to the PC/SC Resource Manager
try {
    $scard->EstablishContext('user');

    // First we'll examine the state of all connected readers to see which have smartcards already inserted..
    // Get JSON containing information about the smartcards currently inserted into readers.
    // This also includes information about USB security tokens.
    $json = new JsonObject();
    $scard->FindSmartcards($json);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// When writing this example, I have 3 smart card readers plugged into my system.
// One of them has a smart card inserted.
// Here's the JSON returned by FindSmartcards...

// {
//   "reader": [
//     {
//       "name": "Alcor Micro USB Smart Card Reader 0",
//       "state": "empty"
//     },
//     {
//       "name": "Generic Smart Card Reader Interface 0",
//       "state": "present",
//       "vendorName": "Generic",
//       "serialNumber": "3230303730383138303030303030303030",
//       "systemName": "Generic Smart Card Reader Interface 0",
//       "card": {
//         "atr": "3BFC180000813180459067464A00641606F2727E00E0",
//         "windows": {
//           "miniDriver": "tagliov70px.dll",
//           "cryptoProvider": "Microsoft Base Smart Card Crypto Provider",
//           "keyStorageProvider": "Microsoft Smart Card Key Storage Provider"
//         }
//       }
//     },
//     {
//       "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
//       "state": "empty"
//     }
//   ]
// }

$json->EmitCompact = false;
echo $json->Emit(), "\n";
echo " \n";

// We can iterate over the JSON to find the readers with a smart card already inserted..
$name = '';
$sbState = new StringBuilder();

$i = 0;
$count_i = $json->SizeOfArray('reader');
while ($i < $count_i) {
    $json->I = $i;
    $name = $json->StringOf('reader[i].name');

    $sbState->Clear();
    $json->StringOfSb('reader[i].state', $sbState);

    if ($sbState->Contains('present', true)) {
        echo $name, " has a smart card inserted.\n";
    } else {
        echo $name, " does not have a smart card inserted.\n";
    }

    $i = $i + 1;
}

echo " \n";

// Now let's begin the code to wait for a change (where a smart card gets inserted or removed)

// Get the list of all readers.
$stReaders = new StringTable();
try {
    $scard->ListReaders($stReaders);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// Show the reader names..
$numReaders = $stReaders->Count;
$i = 0;
while ($i < $numReaders) {
    echo $i, ': ', $stReaders->StringAt($i), "\n";
    $i = $i + 1;
}

// Sample output from the above loop.
// 0: Alcor Micro USB Smart Card Reader 0
// 1: Generic Smart Card Reader Interface 0
// 2: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
//

// Synchronously wait 30 seconds for a card to be inserted or removed from any of the above readers.
$json2 = new JsonObject();
try {
    $scard->GetStatusChange(30000, $stReaders, $json2);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo " \n";

// Let's see what happened...
$json2->EmitCompact = false;
echo $json2->Emit(), "\n";
echo " \n";

// This is what json2 contains.
// A card was inserted into the reader named "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
// The "numChanged" indicates that one reader's status changed.
// The "changed":true indicates the reader that changed.   The state is now "present".

// {
//   "numChanged": 1,
//   "reader": [
//     {
//       "name": "Alcor Micro USB Smart Card Reader 0",
//       "changed": false,
//       "state": "empty"
//     },
//     {
//       "name": "Generic Smart Card Reader Interface 0",
//       "changed": false,
//       "state": "present",
//       "atr": "3BFC180000813180459067464A00641606F2727E00E0"
//     },
//     {
//       "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
//       "changed": true,
//       "state": "present",
//       "atr": "3BDF96FF8131FE455A018048494443313158587300011B09"
//     }
//   ]
// }

// Find the reader that changed...
$changed = false;
$state = '';
$atr = '';

$numChanged = $json2->IntOf('numChanged');
echo 'number of readers with a changed state: ', $numChanged, "\n";

$i = 0;
$count_i = $json2->SizeOfArray('reader');
while ($i < $count_i) {
    $json2->I = $i;
    $changed = $json2->BoolOf('reader[i].changed');
    if ($changed) {
        $name = $json2->StringOf('reader[i].name');
        $state = $json2->StringOf('reader[i].state');

        echo "Changed: \n";
        echo '    reader name: ', $name, "\n";
        echo '    new state: ', $state, "\n";

        // If a card is now in this reader, we should have the ATR of the card..
        if ($json2->HasMember('reader[i].atr')) {
            $atr = $json2->StringOf('reader[i].atr');
            echo '    ATR of card inserted into this reader: ', $atr, "\n";
        }
    }

    $i = $i + 1;
}

// The output from the above loop:

// number of readers with a changed state: 1
// Changed:
//     reader name: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
//     new state: present
//     ATR of card inserted into this reader: 3BDF96FF8131FE455A018048494443313158587300011B09

// Applications should always release the context when finished.
try {
    $scard->ReleaseContext();
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
}