added the CGI get example

derekmolloy · Mar 25, 2015 · 20bea25 · 20bea25
1 parent 34f6e51
commit 20bea25
Show file tree

Hide file tree

Showing 7 changed files with 148 additions and 1 deletion.
diff --git a/chp10/cgicc/LED.cpp b/chp10/cgicc/LED.cpp
@@ -0,0 +1,51 @@
+#include "LED.h"
+
+LED::LED(int number){
+   this->number = number;
+   // much easier with C++11 using to_string(number)
+   ostringstream s;    // using a stream to contruct the path
+   s << LED_PATH << number;   //append LED number to LED_PATH
+   path = string(s.str());    //convert back from stream to string
+}
+
+void LED::writeLED(string filename, string value){
+   ofstream fs;
+   fs.open((path + filename).c_str());
+   fs << value;
+   fs.close();
+}
+
+void LED::removeTrigger(){
+   writeLED("/trigger", "none");
+}
+
+void LED::turnOn(){
+   cout << "Turning LED" << number << " on." << endl;
+   removeTrigger();
+   writeLED("/brightness", "1");
+}
+
+void LED::turnOff(){
+   cout << "Turning LED" << number << " off." << endl;
+   removeTrigger();
+   writeLED("/brightness", "0");
+}
+
+void LED::flash(string delayms = "50"){
+   cout << "Making LED" << number << " flash." << endl;
+   writeLED("/trigger", "timer");
+   writeLED("/delay_on", delayms);
+   writeLED("/delay_off", delayms);
+}
+
+void LED::outputState(){
+   ifstream fs;
+   fs.open( (path + "/trigger").c_str());
+   string line;
+   while(getline(fs,line)) cout << line << endl;
+   fs.close();
+}
+
+LED::~LED(){
+   cout << "destroying the LED with path: " << path << endl;
+}
diff --git a/chp10/cgicc/LED.h b/chp10/cgicc/LED.h
@@ -0,0 +1,36 @@
+/** Simple On-board LED flashing program - written by Derek Molloy
+*    simple OOP  struture for the Exploring BeagleBone book
+*
+*    This program uses all four LEDS and can be executed in three ways:
+*         makeLEDs on
+*         makeLEDs off
+*         makeLEDs flash  (flash at time delay intervals)
+*         makeLEDs status (get the trigger status)
+*
+* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and
+* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
+* ISBN 9781118935125. Please see the file README.md in the repository root
+* directory for copyright and GNU GPLv3 license information.            */
+
+#include<iostream>
+#include<fstream>
+#include<string>
+#include<sstream>
+using namespace std;
+
+#define LED_PATH "/sys/class/leds/beaglebone:green:usr"
+
+class LED{
+   private:
+      string path;
+      int number;
+      virtual void writeLED(string filename, string value);
+      virtual void removeTrigger();
+   public:
+      LED(int number);
+      virtual void turnOn();
+      virtual void turnOff();
+      virtual void flash(string delayms);
+      virtual void outputState();
+      virtual ~LED();
+};
diff --git a/chp10/cgicc/build b/chp10/cgicc/build
@@ -1,3 +1,6 @@
 #!/bin/bash
 echo "Building the hello.cgi C++ CGI Program"
 g++ hello.cpp -o hello.cgi
+
+echo "Building the getLED.cgi C++ CGI Program"
+g++ getLED.cpp LED.cpp -o getLED.cgi -lcgicc
diff --git a/chp10/cgicc/deploy b/chp10/cgicc/deploy
@@ -0,0 +1,4 @@
+#!/bin/bash
+echo "Copying the cgi files to the /usr/lib/cgi-bin/"
+sudo cp *.cgi /usr/lib/cgi-bin/
+sudo chmod +s /usr/lib/cgi-bin/getLED.cgi
diff --git a/chp10/cgicc/getLED.cgi b/chp10/cgicc/getLED.cgi
diff --git a/chp10/cgicc/getLED.cpp b/chp10/cgicc/getLED.cpp
@@ -0,0 +1,53 @@
+/* C++ CGI BeagleBone GET example -- Written by Derek Molloy (www.derekmolloy.ie) 
+	You must set the sticky bit for this script in order that it can
+	access the on-board LED sysfs file system.
+*/
+
+#include <iostream>         // for the input/output
+#include <stdlib.h>         // for the getenv call
+#include <sys/sysinfo.h>    // for the system uptime call
+
+#include <cgicc/Cgicc.h>    // the cgicc headers
+#include <cgicc/CgiDefs.h>
+#include <cgicc/HTTPHTMLHeader.h>
+#include <cgicc/HTMLClasses.h>
+
+#include "LED.h"            // the LED class from Chapter 5 of the book
+
+using namespace std;
+using namespace cgicc;
+
+int main(){
+	Cgicc form;
+	LED *led3 = new LED(3);
+
+	char *value = getenv("REMOTE_ADDR");           // The remote address CGI environment variable
+	cout << "Content-type:text/html\r\n\r\n";      // Generate the HTML output
+	cout << "<html><head>\n";
+	cout << "<title>EBB C++ GET Example</title>\n";
+	cout << "</head><body>\n";
+	cout << "<h1>BeagleBone GET Example</h1>\n";
+
+	form_iterator it = form.getElement("command");
+	string cmd(**it);
+	if (!it->isEmpty() && it!=(*form).end()) {
+		cout << "<div> The LED command is " << cmd << ".</div>";
+
+		/** This code sets the USR3 LED state using the LED class **/
+		if(cmd=="on") led3->turnOn();
+		else if(cmd=="off") led3->turnOff();
+		else if(cmd=="flash") led3->flash("100");
+		else if(cmd=="status"){
+			cout << "<div>";
+			led3->outputState();
+			cout << "</div>";
+		}
+		else cout << "<div> Invalid command! </div>";
+	}
+	else{
+		cout << "<div> The LED command is missing or invalid.</div>";
+	}
+	cout << "<div> The CGI REMOTE_ADDR environment variable is " << value << "</div>";
+	cout << "</body></html>\n";
+	return 0;
+}
diff --git a/chp10/cgicc/hello.cpp b/chp10/cgicc/hello.cpp
@@ -15,7 +15,7 @@ int main(){
 	cout << "</head><body>\n";
 	cout << "<h1>BeagleBone System Uptime</h1>\n";
 	int mins = info.uptime / 60;                   // the uptime comes from the sysinfo struct
-        int ram = info.freeram / 1024 / 1024;          // the available memory in Mb
+	int ram = info.freeram / 1024 / 1024;          // the available memory in Mb
 	cout << "<div> The BBB system uptime is " << mins << " minutes.\n";
 	cout << "There is " << ram << " Mb of memory available.</div>\n";
 	cout << "<div> The CGI REMOTE_ADDR environment variable is " << value << "</div>";