Save buffers of a detached or otherwise inaccessible emacs process.

sti.c

#include <err.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <termios.h>

const char* const kJesusSaves = "\025\033xsave-buffers-kill-emacs\n";

int main(int argc, char* argv[]) {
  int fd = open(argv[1], O_WRONLY);
  if (fd < 0) {
    err(1, "open");
  }
  for (const char* c = kJesusSaves; *c; ++c) {
    if (ioctl(fd, TIOCSTI, c) < 0) {
      err(1, "TIOCSTI");
    }
  }
}