CGI-based applications for distributed embedded systems for monitoring temperature and humidity

Embedded Web Server and Database Based on Wap

“…The right code shows how to call driver application. The program read led.html file into buffer and send to client,then the led number-cgivars [1] will be read ,led state-cgivars [3] will be compared to set the led on/off, finally the driver will be called through system(comd) , the system call can submit specific command with argument to linux shell. The command with argument is stored in string "comd".…”

“…From the viewpoint of the embedded world, webpage based methods can be classified into two categories: ACTIVEX based method and CGI based method [3]. However, the ACTIVE based method can only be used on windows IE platform.…”

Embedded Web Server Architecture for Mobile Phone

“…To support this function, the cgi will call the driver, the next application show how driver be called. int main(int argc, char **argv) { int led_no,on; unsigned char led=0xff; if (argc != 3 || sscanf(argv [1], "%d", &led_no) != 1 || sscanf(argv [2],"%d", &on) != 1 ||on < 0 || on > 1 || led_no < 0 || led_no > 7) { fprintf(stderr, "Usage: leds led_no 0|1\n"); exit(1); } if(on) led&=~(0x1<<led_no);else led|=(0x1<<led_no); fd = open(LED_DEV, O_RDWR); if(fd < 0) {printf("####XSB_EDR_8LED test device open fail####%d \n",fd); return (-1);} write(fd,&led,1); } close(fd); return(0); } The above example shows that error checking and driver interface are mixed in same file. After business workflow added, the code will be very complicated.…”

“…The limitation of desktop based application is that it impossible running on various mobile phones, so webpage based application is more widely adopted. On pc environment ,webpage based methods can be classified into two categories: ACTIVEX based method and CGI based method [2]. In activex based method, user interaction modules are implemented in ACTIVEX and it will be installed when user login the webpage first time.…”

A CGI+AJAX+SVG based monitoring method for distributed and embedded system

“…CGI (Common Gateway Interface) [1] is a way of creating dynamical web pages, through which, the client can monitor the states of the controlled embedded devices distributed somewhere. As a standard interface between an external application (gateway) and information server (HTTP), there is no need to build a special client but a common web browser and transform C/S architecture to B/S architecture to implement two ways of communication, which means that in a distributed and embedded system, the server nodes can show and change their internal state on a client's request.…”