gmgauthier/socket-samples
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fixed ansi client

Browse Source
This commit is contained in:
Gregory Gauthier 2026-03-26 14:13:12 +00:00
parent 2799184ffb
commit d0f13d9078
2 changed files with 232 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

177
src/c90/metric_client_ansi.c Normal file
View File

@ -0,0 +1,177 @@
/* metric_client.c - STRICT C89/C90 clean live client with unsub */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/select.h>
#include <errno.h>
#define PORT 9999
#define BUF_SIZE 1024
#define MSG_PING 0x01
#define MSG_PONG 0x02
#define MSG_METRIC_REQ 0x03
#define MSG_METRIC_RESP 0x04
#define MSG_SUBSCRIBE 0x05
#define MSG_PUSH 0x06
#define MSG_UNSUB 0x07
#define MSG_ERROR 0xFF
#define HEADER_SIZE 3
static void send_message(int sock, unsigned char type,
const void *payload, unsigned short len)
{
unsigned char header[HEADER_SIZE];
header[0] = type;
header[1] = (len >> 8) & 0xFF;
header[2] = len & 0xFF;
write(sock, header, HEADER_SIZE);
if (len > 0)
write(sock, payload, len);
}
static int recv_exact(int sock, void *buf, int n)
{
int total = 0;
while (total < n) {
int r = read(sock, (char *)buf + total, n - total);
if (r <= 0) return -1;
total += r;
}
return total;
}
static void print_wire_comparison(void)
{
printf("\n--- Wire overhead comparison ---\n");
printf("Our protocol (METRIC_REQ 'cpu'): %d bytes\n", HEADER_SIZE + 3);
printf("Equivalent HTTP GET: 77 bytes\n");
printf("HTTP is ~13x larger\n\n");
}
int main(void)
{
int sock, maxfd;
struct sockaddr_in addr;
unsigned char header[HEADER_SIZE];
unsigned char payload[BUF_SIZE];
double val;
char line[256];
unsigned char type;
unsigned short len;
fd_set readfds;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) { perror("socket"); exit(1); }
addr.sin_family = AF_INET;
addr.sin_port = htons(PORT);
inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr);
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("connect"); close(sock); exit(1);
}
printf("Connected to 127.0.0.1:%d (clean C89 client)\n", PORT);
print_wire_comparison();
printf("Commands: ping | get <metric> | sub <metric> <ms> | unsub | quit\n");
printf("Metrics: cpu, memory, disk, loadavg, uptime\n\n");
printf("> "); fflush(stdout);
maxfd = sock + 1;
while (1) {
FD_ZERO(&readfds);
FD_SET(0, &readfds);
FD_SET(sock, &readfds);
if (select(maxfd, &readfds, NULL, NULL, NULL) < 0) {
if (errno == EINTR) continue;
perror("select");
break;
}
/* 1. Async message from server */
if (FD_ISSET(sock, &readfds)) {
if (recv_exact(sock, header, HEADER_SIZE) != HEADER_SIZE) break;
type = header[0];
len = (header[1] << 8) | header[2];
if (len > 0) {
if (recv_exact(sock, payload, len) != len) break;
}
/* Clear current input line */
printf("\r\x1b[2K");
if (type == MSG_PONG) {
printf(" [PONG] server alive\n");
} else if (type == MSG_METRIC_RESP) {
memcpy(&val, payload, sizeof(double));
printf(" [METRIC] %.2f\n", val);
} else if (type == MSG_PUSH) {
unsigned char name_len = payload[0];
payload[1 + name_len] = '\0';
memcpy(&val, payload + 1 + name_len, sizeof(double));
printf(" [PUSH] %s: %.2f\n", (char *)payload + 1, val);
} else if (type == MSG_ERROR) {
payload[len] = '\0';
printf(" [ERROR] %s\n", payload);
}
printf("> "); fflush(stdout);
}
/* 2. User input */
if (FD_ISSET(0, &readfds)) {
if (fgets(line, sizeof(line), stdin) == NULL) break;
line[strcspn(line, "\n")] = '\0';
if (strcmp(line, "quit") == 0) break;
else if (strcmp(line, "ping") == 0) {
send_message(sock, MSG_PING, NULL, 0);
}
else if (strncmp(line, "get ", 4) == 0) {
const char *metric = line + 4;
send_message(sock, MSG_METRIC_REQ, metric, strlen(metric));
}
else if (strncmp(line, "sub ", 4) == 0) {
char *metric = strtok(line + 4, " ");
if (metric) {
unsigned int ms = atoi(strtok(NULL, " "));
unsigned char name_len = strlen(metric);
unsigned char p[BUF_SIZE];
p[0] = name_len;
memcpy(p + 1, metric, name_len);
p[1 + name_len] = (ms >> 24) & 0xFF;
p[1 + name_len + 1] = (ms >> 16) & 0xFF;
p[1 + name_len + 2] = (ms >> 8) & 0xFF;
p[1 + name_len + 3] = ms & 0xFF;
send_message(sock, MSG_SUBSCRIBE, p, 1 + name_len + 4);
printf(" Subscribed to '%s' every %u ms\n", metric, ms);
}
}
else if (strcmp(line, "unsub") == 0) {
send_message(sock, MSG_UNSUB, NULL, 0);
printf(" Unsubscribed (push stopped)\n");
}
else if (line[0] != '\0') {
printf(" Unknown command.\n");
}
printf("> "); fflush(stdout);
}
}
close(sock);
printf("\nDisconnected.\n");
return 0;
}

84
src/c90/metric_server_fork_sub.c
View File

@ -1,4 +1,4 @@
/* metric_server_fork.c - STRICT C89/C90 multi-client metric server with SUBSCRIBE/PUSH */ /* metric_server_fork.c - STRICT C89/C90 multi-client metric server with SUBSCRIBE/PUSH (fixed) */
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
@ -9,6 +9,7 @@
#include <time.h> #include <time.h>
#include <signal.h> #include <signal.h>
#include <errno.h> #include <errno.h>
#include <sys/select.h>
#define PORT 9999 #define PORT 9999
#define BACKLOG 10 #define BACKLOG 10
@ -41,7 +42,7 @@ static void send_message(int sock, unsigned char type,
header[0] = type; header[0] = type;
header[1] = (len >> 8) & 0xFF; header[1] = (len >> 8) & 0xFF;
header[2] = len & 0xFF; header[2] = len & 0xFF;
write(sock, header, HEADER_SIZE); if (write(sock, header, HEADER_SIZE) != HEADER_SIZE) return;
if (len > 0) if (len > 0)
write(sock, payload, len); write(sock, payload, len);
} }
@ -65,14 +66,52 @@ static void handle_client(int client_sock, struct sockaddr_in *addr)
unsigned char type; unsigned char type;
unsigned short len; unsigned short len;
double val; double val;
char *metric_name; fd_set readfds;
unsigned int interval_ms; struct timeval tv;
unsigned char name_len; int retval;
/* Subscription state (one active subscription per client for this demo) */
char subscribed_metric[64] = {0};
unsigned int interval_ms = 0;
int have_subscription = 0;
inet_ntop(AF_INET, &addr->sin_addr, client_ip, sizeof(client_ip)); inet_ntop(AF_INET, &addr->sin_addr, client_ip, sizeof(client_ip));
printf("[+] Connected from %s:%d\n", client_ip, ntohs(addr->sin_port)); printf("[+] Connected from %s:%d\n", client_ip, ntohs(addr->sin_port));
while (1) { while (1) {
FD_ZERO(&readfds);
FD_SET(client_sock, &readfds);
/* If we have a subscription, set a timeout for the next PUSH */
if (have_subscription && interval_ms > 0) {
tv.tv_sec = interval_ms / 1000;
tv.tv_usec = (interval_ms % 1000) * 1000;
retval = select(client_sock + 1, &readfds, NULL, NULL, &tv);
} else {
retval = select(client_sock + 1, &readfds, NULL, NULL, NULL);
}
if (retval < 0) {
if (errno == EINTR) continue;
perror("select");
break;
}
/* Timeout fired → send PUSH */
if (retval == 0 && have_subscription) {
val = get_metric(subscribed_metric);
if (val >= 0.0) {
unsigned char name_len = strlen(subscribed_metric);
payload[0] = name_len;
memcpy(payload + 1, subscribed_metric, name_len);
memcpy(payload + 1 + name_len, &val, sizeof(double));
send_message(client_sock, MSG_PUSH, payload, 1 + name_len + sizeof(double));
printf(" -> PUSH '%s' to %s\n", subscribed_metric, client_ip);
}
continue;
}
/* Data from client */
if (recv_exact(client_sock, header, HEADER_SIZE) != HEADER_SIZE) if (recv_exact(client_sock, header, HEADER_SIZE) != HEADER_SIZE)
break; break;
@ -100,30 +139,17 @@ static void handle_client(int client_sock, struct sockaddr_in *addr)
} }
} }
else if (type == MSG_SUBSCRIBE) { else if (type == MSG_SUBSCRIBE) {
name_len = payload[0]; unsigned char name_len = payload[0];
payload[name_len + 1] = '\0'; if (name_len < sizeof(subscribed_metric)-1) {
metric_name = (char *)payload + 1; memcpy(subscribed_metric, payload + 1, name_len);
interval_ms = (payload[name_len + 1] << 24) | subscribed_metric[name_len] = '\0';
(payload[name_len + 2] << 16) |
(payload[name_len + 3] << 8) |
payload[name_len + 4];
printf(" -> SUBSCRIBE '%s' every %u ms from %s\n", metric_name, interval_ms, client_ip);
/* Simple push loop inside this child process */
while (1) {
val = get_metric(metric_name);
if (val < 0.0) break;
name_len = strlen(metric_name);
payload[0] = name_len;
memcpy(payload + 1, metric_name, name_len);
memcpy(payload + 1 + name_len, &val, sizeof(double));
send_message(client_sock, MSG_PUSH,
payload, 1 + name_len + sizeof(double));
usleep(interval_ms * 1000);
} }
interval_ms = (payload[1 + name_len] << 24) |
(payload[1 + name_len + 1] << 16) |
(payload[1 + name_len + 2] << 8) |
payload[1 + name_len + 3];
have_subscription = 1;
printf(" -> SUBSCRIBE '%s' every %u ms from %s\n", subscribed_metric, interval_ms, client_ip);
} }
else { else {
const char *err = "Unknown message type"; const char *err = "Unknown message type";
@ -159,7 +185,7 @@ int main(void)
perror("listen"); exit(1); perror("listen"); exit(1);
} }
printf("Metric server (fork() + SUBSCRIBE/PUSH) listening on port %d\n", PORT); printf("Metric server (fork() + SUBSCRIBE/PUSH with select()) listening on port %d\n", PORT);
printf("Available metrics: cpu, memory, disk, loadavg, uptime\n"); printf("Available metrics: cpu, memory, disk, loadavg, uptime\n");
printf("Commands: ping, get <metric>, sub <metric> <ms>\n\n"); printf("Commands: ping, get <metric>, sub <metric> <ms>\n\n");