Re: [Bug-wget] [PATCH] wget: Add --ssh-askpass support

[Eli Zaretskii]

> From: "Liam R. Howlett" <address@hidden>
> Date: Fri, 22 Jul 2016 20:24:05 -0400
> Cc: address@hidden
> 
> This adds the --ssh-askpass option which is disabled by default.

Thanks.

> +
> +/* Execute external application SSH_ASKPASS which is stored in 
> opt.ssh_askpass
> + */
> +void
> +run_ssh_askpass(const char *question, char **answer)
> +{
> +  char tmp[1024];
> +  pid_t pid;
> +  int com[2];
> +
> +  if (pipe(com) == -1)
> +  {
> +    fprintf(stderr, _("Cannot create pipe"));
> +    exit (WGET_EXIT_GENERIC_ERROR);
> +  }
> +
> +  pid = fork();
> +  if (pid == -1)
> +  {
> +    fprintf(stderr, "Error forking SSH_ASKPASS");
> +    exit (WGET_EXIT_GENERIC_ERROR);
> +  }
> +  else if (pid == 0)
> +  {
> +    /* Child */
> +    dup2(com[1], STDOUT_FILENO);
> +    close(com[0]);
> +    close(com[1]);
> +    fprintf(stdout, "test");
> +    execlp("/usr/bin/strace", "-s256", "-otest.out", opt.ssh_askpass, 
> question, (char*)NULL);
> +    assert("Execlp failed!");
> +  }
> +  else
> +  {
> +    close(com[1]);
> +    unsigned int bytes = read(com[0], tmp, sizeof(tmp));
> +    if (!bytes)
> +    {
> +      fprintf(stderr,
> +        _("Error reading response from SSH_ASKPASS %s %s\n"),
> +        opt.ssh_askpass, question);
> +      exit (WGET_EXIT_GENERIC_ERROR);
> +    }
> +    else if (bytes > 1)
> +      *answer = strndup(tmp, bytes-1);
> +  }
> +}

This implementation is unnecessarily non-portable ('fork' doesn't
exist on some supported platforms).  I suggest to use a much more
portable 'popen' instead.