Make examples more robust and link to higher level abstractions

Author: clue

examples/04-signals.php

@@ -2,11 +2,18 @@
 
 require __DIR__ . '/../vendor/autoload.php';
 
+if (!defined('SIGINT')) {
+    fwrite(STDERR, 'Not supported on your platform (ext-pcntl missing or Windows?)' . PHP_EOL);
+    exit(1);
+}
+
 $loop = React\EventLoop\Factory::create();
 
 $loop->addSignal(SIGINT, $func = function ($signal) use ($loop, &$func) {
     echo 'Signal: ', (string)$signal, PHP_EOL;
     $loop->removeSignal(SIGINT, $func);
 });
 
+echo 'Listening for SIGINT. Use "kill -SIGINT ' . getmypid() . '" or CTRL+C' . PHP_EOL;
+
 $loop->run();

examples/11-consume-stdin.php

@@ -4,19 +4,23 @@
 
 require __DIR__ . '/../vendor/autoload.php';
 
-if (stream_set_blocking(STDIN, false) !== true) {
-    fwrite(STDERR, 'ERROR: Unable to set STDIN non-blocking' . PHP_EOL);
+if (!defined('STDIN') || stream_set_blocking(STDIN, false) !== true) {
+    fwrite(STDERR, 'ERROR: Unable to set STDIN non-blocking (not CLI or Windows?)' . PHP_EOL);
     exit(1);
 }
 
 $loop = Factory::create();
 
+// read everything from STDIN and report number of bytes
+// for illustration purposes only, should use react/stream instead
 $loop->addReadStream(STDIN, function ($stream) use ($loop) {
     $chunk = fread($stream, 64 * 1024);
 
     // reading nothing means we reached EOF
     if ($chunk === '') {
         $loop->removeReadStream($stream);
+        stream_set_blocking($stream, true);
+        fclose($stream);
         return;
     }
 

examples/12-generate-yes.php

@@ -10,20 +10,22 @@
 
 $loop = React\EventLoop\Factory::create();
 
-$stdout = STDOUT;
-if (stream_set_blocking($stdout, false) !== true) {
-    fwrite(STDERR, 'ERROR: Unable to set STDOUT non-blocking' . PHP_EOL);
+if (!defined('STDOUT') || stream_set_blocking(STDOUT, false) !== true) {
+    fwrite(STDERR, 'ERROR: Unable to set STDOUT non-blocking (not CLI or Windows?)' . PHP_EOL);
     exit(1);
 }
 
-$loop->addWriteStream($stdout, function () use ($loop, $stdout, &$data) {
+// write data to STDOUT whenever its write buffer accepts data
+// for illustrations purpose only, should use react/stream instead
+$loop->addWriteStream(STDOUT, function ($stdout) use ($loop, &$data) {
     // try to write data
     $r = fwrite($stdout, $data);
 
     // nothing could be written despite being writable => closed
     if ($r === 0) {
         $loop->removeWriteStream($stdout);
         fclose($stdout);
+        stream_set_blocking($stdout, true);
         fwrite(STDERR, 'Stopped because STDOUT closed' . PHP_EOL);
 
         return;

examples/21-http-server.php

@@ -4,9 +4,15 @@
 
 $loop = React\EventLoop\Factory::create();
 
+// start TCP/IP server on localhost:8080
+// for illustration purposes only, should use react/socket instead
 $server = stream_socket_server('tcp://127.0.0.1:8080');
-stream_set_blocking($server, 0);
+if (!$server) {
+    exit(1);
+}
+stream_set_blocking($server, false);
 
+// wait for incoming connections on server socket
 $loop->addReadStream($server, function ($server) use ($loop) {
     $conn = stream_socket_accept($server);
     $data = "HTTP/1.1 200 OK\r\nContent-Length: 3\r\n\r\nHi\n";