Here is my main.go

package main

/*
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

// Global variable to store old action
struct sigaction old_action;

// Signal handler function
void handler(int signum, siginfo_t *info, void *context) {
    printf("Received signal: %dn", signum);
    printf("Sent by PID: %dn", info->si_pid);
    printf("Signal code: %dn", info->si_code);
    printf("User ID: %dn", info->si_uid);
    if (info->si_pid != 0) {
        char proc_status_path[256];
        snprintf(proc_status_path, sizeof(proc_status_path), "/proc/%d/status", info->si_pid);
        FILE *fp = fopen(proc_status_path, "r");
        if (fp == NULL) {
            perror("fopen");
            return;
        }
        char buffer[256];
        while (fgets(buffer, sizeof(buffer), fp)) {
            printf("%s", buffer);
        }
        fclose(fp);
    }
}


// Function to set up signal handling
void setup_signal_handler() {
    struct sigaction action;
    // Initialize the action structure
    memset(&action, 0, sizeof(action));
    sigfillset(&action.sa_mask); // Block all signals while the handler is executing
    action.sa_sigaction = handler; // Set the signal handler function
    action.sa_flags = SA_SIGINFO | SA_ONSTACK; // Set flags

    // Set up the signal handler for SIGTERM
    if (sigaction(SIGTERM, &action, &old_action) < 0) {
        perror("sigaction");
        exit(EXIT_FAILURE);
    }
}
*/
import "C"
import "fmt"

func main() {
    C.setup_signal_handler()
    for {
        fmt.Println("Sleeping..., waiting for signal")
        C.sleep(10)
    }
}

I am trying to use C language to help me to handler signal and print out the pid of signal sender. The original Go packages(syscall, os,… etc) does not provide such information. However, when I run my code above, there are two process starts up. One is go run . and the other one is signal, which is the name of my go package. When I send signal to go run ., nothing happens while to signal, informations pop up.

What I understand is that the implicity C package fork another process to run those C code. I cannot apply the signal handler in C to my go process.

My goal is to print out informations of any kind of signal sent to my go process. Related informations should include at least pid, ppid. Maybe there is another better solution for my situation.