On Tue, Aug 06, 2019 at 02:50:08PM -0400, J. Bruce Fields wrote: > On Tue, Aug 06, 2019 at 03:19:31PM +0300, Andy Shevchenko wrote: > > On Thu, Jun 20, 2019 at 10:51:07AM -0400, J. Bruce Fields wrote: > > > From: "J. Bruce Fields" <bfields@xxxxxxxxxx> > > > > > > I'm exposing some information about NFS clients in pseudofiles. I > > > expect to eventually have simple tools to help read those pseudofiles. > > > > > > But it's also helpful if the raw files are human-readable to the extent > > > possible. It aids debugging and makes them usable on systems that don't > > > have the latest nfs-utils. > > > > > > A minor challenge there is opaque client-generated protocol objects like > > > state owners and client identifiers. Some clients generate those to > > > include handy information in plain ascii. But they may also include > > > arbitrary byte sequences. > > > > > > I think the simplest approach is to limit to isprint(c) && isascii(c) > > > and escape everything else. > > > > > > That means you can just cat the file and get something that looks OK. > > > Also, I'm trying to keep these files legal YAML, which requires them to > > > UTF-8, and this is a simple way to guarantee that. > > > > Two questions: > > - why can't be original function extended to cover this case > > (using additional flags, maybe)? > > I found the ESCAPE_NP/"only" logic made it a little difficult to extend > string_escape_mem(). Maybe it requires more thinking about? I think it is still possible to extend existing, rather to take workarounds like this one. > So, I wrote a patch series that removes the string_escape_mem flags that > aren't used Have you considered the potential users that can be converted to use string_escape_mem()? I know about at least one (needs to be reworked a bit, but it is in slow progress). There are potentially others that would be converted using "unused" flags. >, simplifies it a bit, then separates the flags into two > different types: those that select which characters to escape > (non-printable, non-ascii, whitespace, etc.) and those that choose a > style of escaping to use (octal, hex, or \\). That seems to make the > code a little easier to extend while still covering the cases people > actually use. I'll try to get those out this week and you can tell me > what you think. Will be glad to help! In any case regarding to this one, I would like rather to see it's never appeared, or now will be gone in favour of string_escape_mem() extension. -- With Best Regards, Andy Shevchenko
