TCP client added

computer_networks/lab/lab1/TCP_client.c

@@ -0,0 +1,55 @@
+/**
+ * /mnt/z/my_git/sixth-semester/computer_networks/lab/lab1/TCP_client.c
+ * @author Avinal Kumar
+ * @since January 27, 2021
+ * Roll Number - 185067
+ *
+ * LAB 1
+*/
+
+// Client side C/C++ program to demonstrate Socket programming
+#include <stdio.h>
+#include <sys/socket.h>
+#include <stdlib.h>
+#include <netinet/in.h>
+#include <string.h>
+#define PORT 2047 // Q1: previously 8080
+
+int main(int argc, char const *argv[])
+{
+    struct sockaddr_in address;
+    int sock = 0, valread;
+    struct sockaddr_in serv_addr;
+    char *hello = "TCP Client: Hello this message has been changed. Did you get it?";
+    char buffer[4096] = {0}; // Q4: changed to 4096
+    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+    {
+        printf("\n Socket creation error \n");
+        return -1;
+    }
+
+    memset(&serv_addr, '0', sizeof(serv_addr));
+
+    serv_addr.sin_family = AF_INET;
+    serv_addr.sin_port = htons(PORT);
+    serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1"); // Q3: changed to localhost
+
+    // Convert IPv4 and IPv6 addresses from text to binary form
+    // This binds the client to localhost
+    /*if(inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr)<=0) 
+	{ 
+		printf("\nInvalid address/ Address not supported \n"); 
+		return -1; 
+	} */
+
+    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
+    {
+        printf("\nConnection Failed \n");
+        return -1;
+    }
+    send(sock, hello, strlen(hello), 0);
+    printf("New message sent\n");
+    valread = read(sock, buffer, 4096); // Q4: changed to 4096
+    printf("%s\n", buffer);
+    return 0;
+}