Question

Using network sockets, write a C program called client that receives three command-line arguments in the form: client host port file and sends a request to a web server. The command-line arguments are hostRepresents the web server to connect to port Represents the port number where a request is sent. Normally an HTTP request is sent over port 80, but this format allows for custom ports file Represents the file requested from the web server Your program should create a client socket that connects to the server indicated by host, and send the following: GET/index.html HTTp/1.1rn Host: www.google.comr\n Ir\n Then, your program should read the entire result and display it on the screen.

Answer 1

Some boring theory: :P

• The Hypertext Transfer Protocol (HTTP) is a stateless application layer protocol.
• In HTTP a client (program) try to establish a connection with other program (Server) to send an HTTP request.
• If connection is establish between the server and client then server sends an http response in order to http request.In HTTP mainly GET and POST method are used to send the request to the server.

More on GET method :

• HTTP get request is generally used to get data from the web-server.
• It has no side effect and it is not supposed to change anything on server. So GET method is idempotent.
• It can be executed more than once without any side effects.
• Get method issued when you click a hyperlink or when you type an URL in an address bar and hit the enter key.

HTTP GET Request in C :

• The basic parameters of GET request are the path of resource and the Host header.
• The host header can be the domain name or IP address of the target machine, where we are sending the request.

Suppose there is a service:

http://www.google.com/ || http://www.google.com/index.html

When we prepared a GET request for the above URL then it would be look like this.

GET /index.html HTTP/1.1 Host: www.google.com

If the server run only single website on a single IP address then you can use IP address as header like

GET /index.html HTTP/1.1 Host: IP Address/localhost

For conclusion the complete C program is as follow:

#include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { char requestToServer[100]={0}; char requestedResourcePath[]="index.html"; char hostAddress[]="www.google.com"; sprintf(requestToServer, "GET /%s HTTP/1.1\r\nHost: %s\r\nContent-Type: text/plain\r\n\r\n", requestedResourcePath, hostAddress); printf("Get Request:\n"); printf("%s", requestToServer); retrn 0; }

Tip: Pay some attention to theoretical concepts whenever you try any practical implementation.

The above program can be modified to get meta data as well. just ping me if you want it. i did not wants to complicate things that's why i'm giving you simple program.

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