UDP Client-Server Communication for Translating “New Generation English” to Formal English

 

Experiment 

UDP Client-Server Communication for Translating “New Generation English” to Formal English

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Aim

To design and implement a UDP client-server program where the client sends a sentence with abbreviations, and the server translates it into formal English.

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Objective

• To understand UDP-based communication
• To implement string processing at the server side
• To perform real-time translation using predefined mappings

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Theory

🌐 UDP Communication

UDP is a connectionless protocol:

• No connection establishment
• Faster communication
• Uses sendto() and recvfrom()

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🧠 Concept Used

• Client sends a sentence with abbreviations
• Server replaces abbreviations using a predefined dictionary
• Translated sentence is sent back

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📘 Abbreviation Mapping

Abbreviation	Meaning
tbh	to be honest
ig	I guess
tbf	to be fair
atm	at the moment
irl	in real life
lol	laughing out loud
asap	as soon as possible
omg	oh my God
ttyl	talk to you later
idk	I don’t know
nvm	never mind

idc                    I don't care

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Algorithm

Client

1. Create UDP socket
2. Input sentence from user
3. Send sentence to server
4. Receive translated sentence
5. Display result

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Server

1. Create UDP socket
2. Bind to port
3. Receive sentence from client
4. Replace abbreviations with full forms
5. Send translated sentence back

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💻 Program

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🔹 Server Program (UDP in C)

#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT 12345

void translate(char *str) {
    struct { char *abbr, *full; } dict[] = {
        {"tbh", "to be honest"},
        {"ig", "I guess"},
        {"tbf", "to be fair"},
        {"atm", "at the moment"},
        {"irl", "in real life"},
        {"lol", "laughing out loud"},
        {"asap", "as soon as possible"},
        {"omg", "oh my God"},
        {"ttyl", "talk to you later"},
        {"idk", "I don't know"},
        {"nvm", "never mind"},
        {"idc", "I don't care"}
    };

    char result[1024] = "";
    char temp[100];
    int i = 0, j;

    while (sscanf(str + i, "%s", temp) == 1) {
        int found = 0;

        for (j = 0; j < 12; j++) {
            if (strcmp(temp, dict[j].abbr) == 0) {
                strcat(result, dict[j].full);
                found = 1;
                break;
            }
        }

        if (!found) {
            strcat(result, temp);
        }

        strcat(result, " ");
        i += strlen(temp) + 1;
    }

    strcpy(str, result);
}

int main() {
    int sockfd;
    char buffer[1024];
    struct sockaddr_in server_addr, client_addr;
    socklen_t len;

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);

    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);

    bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr));

    printf("UDP Server running...\n");

    len = sizeof(client_addr);

    recvfrom(sockfd, buffer, sizeof(buffer), 0,
             (struct sockaddr *)&client_addr, &len);

    printf("Received: %s\n", buffer);

    translate(buffer);

    sendto(sockfd, buffer, strlen(buffer)+1, 0,
           (struct sockaddr *)&client_addr, len);

    close(sockfd);
    return 0;
}

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🔹 Client Program (UDP in C)

#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT 12345

int main() {
    int sockfd;
    char buffer[1024];
    struct sockaddr_in server_addr;
    socklen_t len;

    sockfd = socket(AF_INET, SOCK_DGRAM, 0);

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    printf("Enter sentence:\n");
    fgets(buffer, sizeof(buffer), stdin);

    sendto(sockfd, buffer, strlen(buffer)+1, 0,
           (struct sockaddr *)&server_addr, sizeof(server_addr));

    len = sizeof(server_addr);

    recvfrom(sockfd, buffer, sizeof(buffer), 0,
             (struct sockaddr *)&server_addr, &len);

    printf("\nTranslated Sentence:\n%s\n", buffer);

    close(sockfd);
    return 0;
}

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▶️ Compilation and Execution

gcc server.c -o server
gcc client.c -o client

Run:

• Terminal 1 → ./server
• Terminal 2 → ./client

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📌 Sample Output

Client Input

Really idc about this server atm but ig it works lol

Client Output

Translated Sentence:
Really i dont care about this server at the moment but I guess it works laughing out loud

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⚠️ Limitations

• Only predefined abbreviations are translated
• Case-sensitive (e.g., “LOL” not handled)
• Punctuation handling is basic

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✅ Result

The UDP client-server program successfully translated informal English abbreviations into formal English and returned the result to the client

This experiment also demonstrates UDP-based communication and highlights how simple string processing can be integrated into network applications.