[Libguestfs] [PATCH nbdkit] server: Add -D nbdkit.environ=1 to dump the environment

[Eric Blake]

On Sun, May 07, 2023 at 11:43:17AM +0100, Richard W.M. Jones wrote:
> This is not secure so should not be used routinely.  Also we do not
> attempt to filter environment variables, so even ones containing
> multiple lines or special characters are all sent to nbdkit_debug.
> 
> The reason for adding this is to allow for debugging the new
> nbd_set_socket_activation_name(3) API added in libnbd 1.16.
> ---

> +static void
> +dump_environment (void)
> +{
> +  size_t i;
> +
> +  for (i = 0; environ[i]; ++i)
> +    nbdkit_debug ("%s", environ[i]);

We have shell_quote in common/utils/quote.c; shouldn't we use it here
to avoid ambiguities when an env-var contains newline?

> +}
> +
> +#endif /* !WIN32 */
> +
>  int
>  main (int argc, char *argv[])
>  {
> @@ -662,6 +682,14 @@ main (int argc, char *argv[])
>    /* Check all debug flags were used, and free them. */
>    free_debug_flags ();
>  
> +#ifndef WIN32
> +  /* Dump the environment if asked.  This is the earliest we can do it
> +   * because it uses a debug flag.
> +   */
> +  if (nbdkit_debug_environ && verbose)
> +    dump_environment ();

Why does this not work on WIN32?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org