Re: [PATCH] tools/xc: restore logging in xc_save

[Olaf Hering <olaf@aepfle.de>]

On Mon, Feb 04, Ian Campbell wrote:

> On Fri, 2013-02-01 at 18:58 +0000, Olaf Hering wrote:
> > +    lvl = si.flags & XCFLAGS_DEBUG ? XTL_DEBUG: XTL_DETAIL;
> > +    lflags = XTL_STDIOSTREAM_HIDE_PROGRESS;
> 
> Would it be useful (as an extension) to implement an XTL_STDIOSTREAM
> flag which makes it output something more suitable for logging,
> e.g. ...10%...20%...30%... 
> (or perhaps automatic based on isatty(outputfd)?)

I was thinking about that, to extend the called progress functions. In
the case of xend.log it would produce many lines of progress.
Since the default xend logging is limited to 1MB, the xend.log file
would be rotated quickly and maybe useful logging output will be lost?

But for other callers of the progress functions it might be useful to
have a parsable output so that they dont have to jump through the hoops.
No idea if any caller makes use of the progress, given that it did not
work at all without the other patch I sent last Friday.

> > +    l = (xentoollog_logger *)xtl_createlogger_stdiostream(stderr, lvl, lflags);
> 
> Might this fail and therefore require error handling?

If it fails then no logging will happen.

> The lvl and lflags variables seem a bit useless to me.

They are there to keep the lines short.

Olaf