Use docker as dev environment

regression/apps/network/tcp_server.c

@@ -0,0 +1,75 @@
+// From: https://www.geeksforgeeks.org/socket-programming-cc/.
+// Some minor modifications are made to the original code base.
+// Lisenced under CCBY-SA.
+
+// Server side C/C++ program to demonstrate socket programming
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#define PORT 8080
+int main(int argc, char const* argv[])
+{
+    int server_fd, new_socket, valread;
+    struct sockaddr_in address;
+    int opt = 1;
+    int addrlen = sizeof(address);
+    char buffer[1024] = { 0 };
+    char* hello = "Hello from server";
+  
+    // Creating socket file descriptor
+    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+        perror("socket failed");
+        exit(EXIT_FAILURE);
+    }
+  
+    // Forcefully attaching socket to the port 8080
+    if (setsockopt(server_fd, SOL_SOCKET,
+                   SO_REUSEADDR | SO_REUSEPORT, &opt,
+                   sizeof(opt))) {
+        perror("setsockopt");
+        exit(EXIT_FAILURE);
+    }
+    address.sin_family = AF_INET;
+    address.sin_port = htons(PORT);
+    // Convert IPv4 and IPv6 addresses from text to binary
+    // form
+    if (inet_pton(AF_INET, "127.0.0.1", &address.sin_addr)
+        <= 0) {
+        printf(
+            "\nInvalid address/ Address not supported \n");
+        return -1;
+    }
+  
+    // Forcefully attaching socket to the port 8080
+    if (bind(server_fd, (struct sockaddr*)&address,
+             sizeof(address))
+        < 0) {
+        perror("bind failed");
+        exit(EXIT_FAILURE);
+    }
+    if (listen(server_fd, 3) < 0) {
+        perror("listen");
+        exit(EXIT_FAILURE);
+    }
+    if ((new_socket
+         = accept(server_fd, (struct sockaddr*)&address,
+                  (socklen_t*)&addrlen))
+        < 0) {
+        perror("accept");
+        exit(EXIT_FAILURE);
+    }
+    valread = read(new_socket, buffer, 1024);
+    printf("%s\n", buffer);
+    send(new_socket, hello, strlen(hello), 0);
+    printf("Hello message sent\n");
+  
+    // closing the connected socket
+    close(new_socket);
+    // closing the listening socket
+    shutdown(server_fd, SHUT_RDWR);
+    return 0;
+}