Re: [Libguestfs] [PATCH nbdkit 9/9] eval, sh: Define $nbdkit_safe_stdio = 0|1 in scripts.

>> Side thought: Both the eval and sh plugins already pass on all >> unrecognized key=value pairs through to the .config callback, and >> error out if the config callback returns missing.  But right now, if >> a script wants to set up an environment variable that will still be >> present to affect later calls, it has to track things itself >> (perhaps by having the .config callback append to $tmpdir/vars, then >> all other callbacks start by 'source $tmpdir/vars').  Would it make >> sense to reserve a special exit value from the .config callback for >> the case where the script wants the current key=value passed to >> config to be preserved to all future callbacks?  Or even state that >> the config callback exiting with status 2 (for missing) is NOT an >> error, but does the key=value preservation automatically? > > Would it be secure, given that plausibly the command line could be > supplied from a different place than the script.  eg. if an untrusted > user sets $PATH ... Interesting thought. That makes me lean more towards a new exit value (for intentional opt-in) rather than reusing status 2 (missing) as the reason to drive the new behavior.