GET and PUT commands with C++ Server-Client - c++

Question

I'm trying to create a server, client put and get method but I don't really know where to start, how do I make the server run the commands I process. Any help would be much appreciated.
Client file
void Copy(char *filename1,char *filename2);
int main(int argc, char **argv)
{
if(argc == 3)
{
int Sockfd;
sockaddr_in ServAddr;
hostent *HostPtr;
int Port = atoi(argv[2]);
int BuffSize = 0;
// get the address of the host
HostPtr = Gethostbyname(argv[1]);
if(HostPtr->h_addrtype != AF_INET)
{
perror("Unknown address type!");
exit(1);
}
memset((char *) &ServAddr, 0, sizeof(ServAddr));
ServAddr.sin_family = AF_INET;
ServAddr.sin_addr.s_addr = ((in_addr*)HostPtr->h_addr_list[0])->s_addr;
ServAddr.sin_port = htons(Port);
// open a TCP socket
Sockfd = Socket(AF_INET, SOCK_STREAM, 0);
// connect to the server
Connect(Sockfd, (sockaddr*)&ServAddr, sizeof(ServAddr));
char userI[256];
// write a message to the server
int dupSockfd = dup(Sockfd);
FILE* writeFile = fdopen(Sockfd, "w");
FILE* readFile = fdopen(dupSockfd, "r");
setlinebuf(writeFile);
char writerBuff[256];
for(;;)
{
cout << "ftp> ";
if(fgets(userI, sizeof(userI), stdin))
{
if(userI == "exit")
{
return 1;
}
else
{
string cmd, f1, f2;
istringstream iss(userI, istringstream::in);
iss >> cmd >> f1 >> f2;
cout << cmd << "." << f1 << "." << f2 << endl;
if(cmd == "get")
{
write(Sockfd, "get", sizeof("get"));
Copy(f1, f2);
}
}
}
}
close(Sockfd);
}
else
{
cout << "Incorrect commands for running... try './client (hostname) (port)'" << endl;
return 1;//
}
return 0;//
}
void Copy(char *filename1,char *filename2) {
const int BUFSIZE=2048;
char buffer[BUFSIZE];
ifstream fin;
ofstream fout;
long filelen, bytesRemaining, bytes;
// Open the file to be transferred, check it exists.
fin.open( filename1);
if (!fin.good())
{
cerr << "Problems opening \"" << filename1 << "\" (" << errno << "): " << strerror(errno) << endl;
exit(1);
}
fout.open(filename2);
if (!fout.good())
{
cerr << "Problems opening \"" << filename2 << "\" (" << errno << "): " << strerror(errno) << endl;
exit(1);
}
// Determine the file's length.
fin.seekg(0,ios::end);
if(fin.fail()) cerr<<"seekg() fail!\n";
filelen = fin.tellg();
if(fin.fail()) cerr<<"tellg() fail!\n";
fin.seekg(0, ios::beg);
if(fin.fail()) cerr<<"seekg() fail!\n";
// Copy the file data.
bytesRemaining = filelen;
while (bytesRemaining > 0)
{
bytes = bytesRemaining > BUFSIZE ? BUFSIZE : bytesRemaining;
fin.read(buffer,bytes);
if(fin.fail()){
cerr<<"read() error\n";
exit(1);
}
fout.write(buffer,bytes);
if(fout.fail()){
cerr<<"write() error\n";
exit(1);
}
bytesRemaining -= bytes;
}
fin.close();
fout.close();
}
Server file
int main(int argc, char **argv)
{
if(argc == 2)
{
int Sockfd, NewSockfd, ClntLen;
sockaddr_in ClntAddr, ServAddr;
int Port = atoi(argv[1]);
char String[MAX_SIZE];
int Len;
// open a TCP socket (an Internet stream socket)
Sockfd = Socket(AF_INET, SOCK_STREAM, 0); // socket() wrapper fn
// bind the local address, so that the client can send to server
memset((char*)&ServAddr, 0, sizeof(ServAddr));
ServAddr.sin_family = AF_INET;
ServAddr.sin_addr.s_addr = htonl(INADDR_ANY);
ServAddr.sin_port = htons(Port);
int opt = 1;
setsockopt(Sockfd,SOL_SOCKET,SO_REUSEADDR, (void*)opt, sizeof(opt));
Bind(Sockfd, (sockaddr*) &ServAddr, sizeof(ServAddr));
// listen to the socket
Listen(Sockfd, 5);
int RecvMsgSize;
for(;;)
{
// wait for a connection from a client; this is an iterative server
ClntLen = sizeof(ClntAddr);
NewSockfd = Accept(Sockfd, (sockaddr*)&ClntAddr, &ClntLen);
if((RecvMsgSize = recv(ClntSocket, EchoBuffer, RCVBUFSIZE, 0)) < 0)
{
perror("recv() failed");
exit(1);
}
// read a message from the client
Len = read(NewSockfd, String, MAX_SIZE);
String[Len] = 0;// make sure it's a proper string
cout<< String << endl;
close(NewSockfd);
}
}
else
{
cout << "Incorrect commands for running... try './server (port)'" << endl;
return 1;//
}
return 0;//
}

Answer 1

You want to create a Web server that will process GET and PUT requests? You first need to read how the http works. Let me explain in simple terms.
Try to develop your server first and connect it to a browser :
1.Make your server listen on port 80 - this is a must
2.Create a buffer that will read the request from the browser(client), as you do in this part of your code:
if((RecvMsgSize = recv(ClntSocket, EchoBuffer, RCVBUFSIZE, 0)) < 0)
{
perror("recv() failed");
exit(1);
}
// read a message from the client
Len = read(NewSockfd, String, MAX_SIZE);
String[Len] = 0;// make sure it's a proper string
cout<< String << endl;
close(NewSockfd);
so this String object is your buffer, it will contain the http request.
3.You need to parse the request. Parse the request to see whether the method is GET PUT POST or etc.
This is a sample GET request :
https://marketing.adobe.com/developer/documentation/data-insertion/r-sample-http-get
4.Then you need to send the proper response back to the client in this case the browser:
http://pastebin.com/BPnVHym5
5.Connect your browser to the server by typing your ip adress in the addressbar

Answer 2

I would honestly use a C++ REST API library to do the work. You can find one called "Casablanca."
Here's an example on how to use it for making a client: https://casablanca.codeplex.com/wikipage?title=Http%20Client%20Tutorial
Here is an example on how to create a server: https://casablanca.codeplex.com/wikipage?title=HTTP%20Listener&referringTitle=Documentation
Maybe this will get you started.