SIGWINCH testing for Cygwin and WSL

winchtest.c

#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

void handler(int signo, siginfo_t *info, void *ctx) {
    struct winsize w;
    ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
    char buf[256];
    sprintf(buf, "%d: (%d,%d)\n", signo, w.ws_col, w.ws_row);
    write(STDOUT_FILENO, buf, strlen(buf));
}

int main() {
    struct sigaction act = { 0 };
    act.sa_sigaction = handler;
    act.sa_flags = SA_RESTART;
    sigaction(SIGWINCH, &act, NULL);
    printf("Commands (press 's' or 'w' then Enter)\n");
    handler(0, NULL, NULL);

    while (true) {
        write(STDOUT_FILENO, "reading: ", strlen("reading: "));
        char buf[256] = { 0 };
        read(STDIN_FILENO, buf, sizeof(buf));
        if (buf[0] == 's') {
            handler(0, NULL, NULL);
        } else if (buf[0] == 'w') {
            write(STDOUT_FILENO, "writing: ", strlen("writing: "));
            for (int i = 0; i < 20; ++i) {
                usleep(200 * 1000);
                write(STDOUT_FILENO, ".", 1);
            }
            write(STDOUT_FILENO, "\n", 1);
        }
    }
}