simple server in C

server.c

// Pure C REST API Server - no external dependencies
// Compile with: gcc -o server server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>

#define PORT 8080
#define BUFFER_SIZE 4096

// Parse HTTP request and extract method and path
void parse_request(char *request, char *method, char *path) {
    sscanf(request, "%s %s", method, path);
}

// Extract body from HTTP request
char* get_body(char *request) {
    char *body = strstr(request, "\r\n\r\n");
    if (body) {
        return body + 4;
    }
    return NULL;
}

// Handle requests
void handle_request(int client_socket, char *request) {
    char method[10], path[100];
    char response[BUFFER_SIZE];
    
    parse_request(request, method, path);
    
    // GET /ping
    if (strcmp(method, "GET") == 0 && strcmp(path, "/ping") == 0) {
        sprintf(response, 
            "HTTP/1.1 200 OK\r\n"
            "Content-Type: text/plain\r\n"
            "Content-Length: 4\r\n"
            "\r\n"
            "pong");
        send(client_socket, response, strlen(response), 0);
    }
    // POST /create
    else if (strcmp(method, "POST") == 0 && strcmp(path, "/create") == 0) {
        char *body = get_body(request);
        
        // Simple response - just acknowledge we got the JSON
        sprintf(response, 
            "HTTP/1.1 200 OK\r\n"
            "Content-Type: application/json\r\n"
            "Content-Length: 23\r\n"
            "\r\n"
            "{\"status\": \"received\"}");
        send(client_socket, response, strlen(response), 0);
    }
}

int main() {
    int server_socket, client_socket;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_len = sizeof(client_addr);
    char buffer[BUFFER_SIZE];
    
    // Create socket
    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket < 0) {
        perror("Socket creation failed");
        exit(1);
    }
    
    // Allow socket reuse
    int opt = 1;
    setsockopt(server_socket, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
    
    // Setup address
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = INADDR_ANY;
    server_addr.sin_port = htons(PORT);
    
    // Bind
    if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("Bind failed");
        exit(1);
    }
    
    // Listen
    if (listen(server_socket, 5) < 0) {
        perror("Listen failed");
        exit(1);
    }
    
    printf("Server running on port %d\n", PORT);
    printf("GET  /ping   - Returns 'pong'\n");
    printf("POST /create - Accepts JSON with username and fruit\n\n");
    
    // Accept connections
    while (1) {
        client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &client_len);
        if (client_socket < 0) {
            perror("Accept failed");
            continue;
        }
        
        // Read request
        memset(buffer, 0, BUFFER_SIZE);
        read(client_socket, buffer, BUFFER_SIZE - 1);
        
        // Handle request
        handle_request(client_socket, buffer);
        
        // Close connection
        close(client_socket);
    }
    
    close(server_socket);
    return 0;
}