C99: modern C for systems that have to work.

#include <stdio.h>

struct server_config {
    const char *host;
    int port;
    int max_clients;
};

int main(void) {
    struct server_config cfg = {
        .host = "127.0.0.1",
        .port = 8080,
        .max_clients = 128
    };

    printf("%s:%d (%d max)\\n", cfg.host, cfg.port, cfg.max_clients);
    return 0;
}

Why this matters: naming fields during initialization guards against ordering mistakes and keeps intent obvious.

#include <stdlib.h>
#include <string.h>

struct point { double x, y, z; };

double *store_point(const struct point *p) {
    double *buf = malloc(3 * sizeof(double));
    if (!buf) return NULL;
    memcpy(buf, p, 3 * sizeof(double));
    return buf;
}

int main(void) {
    double *packed = store_point(&(struct point){ .x = 1.0, .y = 0.5, .z = -0.25 });
    free(packed);
    return 0;
}

Why this matters: compound literals keep temporaries localized and reduce boilerplate in allocation-heavy paths.

#include <stddef.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdio.h>

uint32_t checksum(const uint8_t *data, size_t len) {
    uint32_t sum = 0;
    for (size_t i = 0; i < len; i++) {
        sum += data[i];
    }
    return sum;
}

int main(void) {
    uint8_t payload[] = { 0x01, 0x02, 0x03, 0xFF };
    printf("sum: %" PRIu32 "\\n", checksum(payload, sizeof payload));
    return 0;
}

Why this matters: fixed-width types and format macros make portable IO straightforward across compilers and targets.