Add client.c

Author: 0x326

CMakeLists.txt

@@ -64,6 +64,9 @@ add_executable(CSE_381_IPC_PIPES
 add_executable(CSE_381_IPC_SHARED_MEMORY
         "CSE 381 (Systems II - OS, Currency, Virtualization, and Security)/IPC (Interprocess Communication)/shared-memory.c")
 
+add_executable(CSE_381_NETWORKING_CLIENT
+        "CSE 381 (Systems II - OS, Currency, Virtualization, and Security)/Networking/client.c")
+
 add_executable(CSE_381_NETWORKING_SERVER
         "CSE 381 (Systems II - OS, Currency, Virtualization, and Security)/Networking/server.c")
 

CSE 381 (Systems II - OS, Currency, Virtualization, and Security)/Networking/client.c

@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <strings.h>
+#include <zconf.h>
+#include <string.h>
+
+#define BUFFER_SIZE 256
+
+int main(int argc, char *argv[]) {
+    // Parse commandline parameters
+    if (argc < 3) {
+        fprintf(stdout, "Usage: %s HOST PORT\n", argv[0]);
+        if (argc < 2) {
+            fputs("HOST is required", stderr);
+        }
+        fputs("PORT is required", stderr);
+        return EXIT_FAILURE;
+    } else if (argc > 2) {
+        fprintf(stdout, "Usage: %s HOST PORT\n", argv[0]);
+        fputs("Too many arguments provided", stderr);
+        return EXIT_FAILURE;
+    }
+
+    struct hostent *host = gethostbyname(argv[1]);
+    int port_number = atoi(argv[2]);
+    
+    if (host == NULL) {
+        fputs("Cannot find specified host", stderr);
+        return EXIT_FAILURE;
+    }
+
+    int socket_file_descriptor = socket(AF_INET, SOCK_STREAM, 0);
+    if (socket_file_descriptor < 0) {
+        fputs("Cannot create IPv4 socket\n", stderr);
+        return EXIT_FAILURE;
+    }
+
+    // Build socket configuration
+    struct sockaddr_in server_address;
+    bzero((char *) &server_address, sizeof(server_address));
+    server_address.sin_family = AF_INET;
+    server_address.sin_port = htons(port_number);
+    bcopy(host->h_addr,
+          (char *) &server_address.sin_addr.s_addr,
+          (size_t) host->h_length);
+
+    // Apply socket configuration and connect to server
+    if (connect(socket_file_descriptor, (struct sockaddr *) &server_address, sizeof(server_address)) < 0) {
+        fputs("Cannot make TCP connection to server\n", stderr);
+        return EXIT_FAILURE;
+    }
+
+    // Write
+    char buffer[BUFFER_SIZE];
+    bzero(buffer, BUFFER_SIZE);
+
+    printf("Enter a message to send to the server: ");
+    fgets(buffer, BUFFER_SIZE - 1, stdin);
+
+    ssize_t bytes_transferred = write(socket_file_descriptor, buffer, strlen(buffer));
+    if (bytes_transferred < 0) {
+        fputs("Cannot write to socket\n", stderr);
+        return EXIT_FAILURE;
+    }
+
+    // Read
+    bzero(buffer, BUFFER_SIZE);
+    bytes_transferred = read(socket_file_descriptor, buffer, BUFFER_SIZE - 1);
+    if (bytes_transferred < 0) {
+        fputs("Cannot read from socket\n", stderr);
+        return EXIT_FAILURE;
+    }
+    printf("Got message in reply: %s\n", buffer);
+
+    return EXIT_SUCCESS;
+}