initial implementation

main.cpp

@@ -0,0 +1,104 @@
+#include <arpa/inet.h>
+#include <array>
+#include <codecvt>
+#include <csignal>
+#include <cstdio>
+#include <fcntl.h>
+#include <fstream>
+#include <iostream>
+#include <memory>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdexcept>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#define PORT 54321
+
+std::string exec(std::string cmd) {
+  std::array<char, 128> buffer;
+  std::string result;
+  std::unique_ptr<FILE, void (*)(FILE *)> pipe(popen(cmd.c_str(), "r"),
+                                               [](FILE *f) -> void {
+                                                 // wrapper to ignore the return
+                                                 // value from pclose() is
+                                                 // needed with newer versions
+                                                 // of gnu g++
+                                                 std::ignore = pclose(f);
+                                               });
+  if (!pipe) {
+    throw std::runtime_error("popen() failed!");
+  }
+  while (fgets(buffer.data(), static_cast<int>(buffer.size()), pipe.get()) !=
+         nullptr) {
+    result += buffer.data();
+  }
+  return result;
+}
+
+int serverSocket;
+
+void safe_exit(int code) {
+
+  std::clog << "Exiting\n";
+  close(serverSocket);
+  exit(code);
+}
+
+int main(int argc, char *argv[]) {
+
+  // signal handlers
+  signal(SIGTERM, safe_exit);
+  signal(SIGINT, safe_exit);
+  signal(SIGQUIT, safe_exit);
+  signal(SIGHUP, safe_exit);
+
+  // error signal handlers
+  signal(SIGSEGV, safe_exit);
+
+  // creating socket
+  serverSocket = socket(AF_INET, SOCK_STREAM, 0);
+
+  // specifying the address
+  sockaddr_in serverAddress;
+  serverAddress.sin_family = AF_INET;
+  serverAddress.sin_port = htons(PORT);
+  serverAddress.sin_addr.s_addr = INADDR_ANY;
+
+  // binding socket.
+  while (bind(serverSocket, (struct sockaddr *)&serverAddress,
+              sizeof(serverAddress)) != 0) {
+    std::cerr << "error binding socket retring\n";
+    sleep(2);
+  }
+
+  // listening to the assigned socket
+  listen(serverSocket, 5);
+
+  // accepting connection request
+  int clientSocket = accept(serverSocket, nullptr, nullptr);
+
+  // recieving data
+  char buffer[1024] = {0};
+  {
+    int RecvRetVal = recv(clientSocket, buffer, sizeof(buffer), 0);
+    if (RecvRetVal > sizeof(buffer) || RecvRetVal < 0) {
+      std::cerr << "recv() returned an error code\n";
+      return RecvRetVal;
+    }
+  }
+  std::cout << "Message from client: " << buffer << std::endl;
+
+  // closing the socket.
+  close(serverSocket);
+
+  return 0;
+}