Re: [Denemo-devel] Help with File modification time???

[Richard Shann]

On Wed, 2012-09-26 at 14:56 -0600, Josue Abarca wrote:
> On Wed, Sep 26, 2012 at 06:46:16PM +0100, Richard Shann wrote:
> > There is a problem with the print view update which comes down to the
> > question: How do you tell if a file has changed.
> > Currently I am using stat() and looking at mtime, but only the seconds
> > are being stored it seems, no sub-second precision.
> > What is the right way to test if a file has changed?
> > Richard
> 
> According to [0] and [1] you can use stat and look at mtim (note: no
> trailing e).
> 
> st_mtim.tv_nsec <- to see the nano seconds.
> 
> (of course the file system must support nanoseconds time stamps)
Thanks - it seems I have been on the right track - I was looking at
tv_nsec in the debugger and it is always 0. IIRC Debian stable uses ext2
filesystem - could it be that it doesn't record nano-second timestamps?
Even if it didn't have the precision to give accurate information it
could always increment tv_nsec by 1 every time it modified a file with
the same value of tv_sec. 
If this is really the situation I guess I should find another way - I
need to do something for the Windows system anyway as that doesn't do
file locking the same way as unix. So I will maybe need to keep changing
the filename that LilyPond stores to, though it is nice to keep the old
one for viewing...

Richard



> 
> [0] 
> http://stackoverflow.com/questions/5086471/how-to-display-file-last-modification-time-on-linux#tab-top
> [1] http://linux.die.net/man/2/stat
>