[augeas-devel] [Matahari] Augeas-based configuration agent

[Radek Novacek]

On Thursday 12 of May 2011 01:01:10 David Lutterkort wrote:
> On Wed, 2011-05-11 at 09:24 +0200, Radek Novacek wrote:
> > (resended as I wasn't member of augeas-devel mailing list)
> > 
> > > I was hoping somebody would just cook up a patch based on augtool ;) It
> > > shouldn't be much more work than doing it (yet again) for standalone
> > > use.
> > 
> > I can try to do it. To be clear, the task is to add method to augeas
> > library called e.g. batch, which takes string argument. In this argument
> > will be command (or semicolon separated list of commands) same as for
> > augtool. What will the method return? True only if all commands
> > succeeds, false otherwise?
> 
> All good questions; I initially thought we could just take parts of
> augtool.c (roughly run_command and everything it depends on) and put it
> behind the API. One of my goals here is that augtool can use this new
> API, without any changes in its behavior.
> 
> Besides how to indicate errors, the other question is how to deal with
> all the printing to stdout and stderr that the various cmd_* handlers in
> augtool.c do right now. One option would be to let the caller pass in
> file pointers for that.
> 
> I am thinking we should add two functions to the API:
> 
>         int aug_srun(augeas *aug,
>                      const char *text, size_t text_len,
>                      FILE *out, unsigned int flags)
> 
> and
> 
>         int aug_frun(augeas *aug,
>                      FILE *in, FILE *out,
>                      unsigned int flags)
> 
> The functions return 0 on success and -1 on error; further details about
> the error can be found with aug_error; if that returns AUG_ECOMMAND,
> something went wrong with parsing a command. We can use
> aug_error_minor_message and aug_error_details to provide more error
> information.
> 
> The commands are either read from TEXT (aug_srun) or from IN (aug_frun,
> reads till EOF); commands must be separated by newlines. I don't think
> there's any point in getting fancy with semicolons.
> 
> If OUT is non-NULL, commands that produce output (e.g.
> 'get /augeas/version' or 'print /files/etc/hosts') will print that on
> OUT. That way, augtool can just pass stdout and the user should see
> output identical to the current output.
> 
> By default, executing commands is aborted when an error is encountered;
> by setting FLAGS to AUG_RUN_CONTINUE, errors are ignored as much as
> possible (e.g., a syntax error will be ignored, but an OOM would still
> lead to returning with an error)
> 
> How does all that sound ? Since this now seems a little more involved
> than I first thought, I might have a crack at it tomorrow. Please let me
> know if the suggested API's would work for you.
> 
> David

Hi, David,

do you have any progress with this feature? I can try to implement it if you 
are busy.

Radek Novacek