Marcel, Thanks for the sample code. Unfortunately, it didn't work in my environment (Mac OS X and CentOS). Essentially the code you've shown and my code is the same, in that both don't re-open the file. It seems we cannot fetch the added data without re-opening, Considering the overhead of opening the file in each "change" event, just spawning "tail -f" would be better as Matt says. What's difficult is that we cannot know at which line the child process of "tail -f" starts to read when the file is growing.
2012/2/9 Marcel Laverdet <[email protected]> > Matt keeps screaming race condition because conditions stated to not be > handled are not handled. > > > On Wed, Feb 8, 2012 at 5:09 PM, Mark Hahn <[email protected]> wrote: > >> That's not really a race, just a condition not covered. >> >> >> On Wed, Feb 8, 2012 at 3:08 PM, Matt <[email protected]> wrote: >> >>> There's a race between when you get the results from stat and re-open >>> the file. You know it's changed, you assume it has grown, so you re-open at >>> "last-byte-read" position. But what if between that time, the file got >>> truncated to zero, meaning you need to read from the start of the file? >>> >>> On Wed, Feb 8, 2012 at 4:36 PM, Adam Pritchard <[email protected] >>> > wrote: >>> >>>> Can you elaborate? I'm pretty new to JS/Node, so maybe I'm not seeing >>>> it. >>>> >>>> I recognize that the file reading isn't one-to-one with the >>>> notifications (i.e., many rapid file modifications will probably be >>>> processed in a single file read, and then following notifications won't >>>> have an effect until the file grows again), but I don't see that that's a >>>> problem -- the data should still get processed in a timely fashion. >>>> >>>> On the other hand... my tests aren't running through successfully on >>>> two of three OSes, so there's certainly something not right... >>>> >>>> I'd appreciate any bugs or flaws you can point out. >>>> >>>> Adam >>>> >>>> >>>> On Wed, Feb 8, 2012 at 11:40 AM, Matt <[email protected]> wrote: >>>> >>>>> Still has a race condition in it. >>>>> >>>>> >>>>> On Tue, Feb 7, 2012 at 8:20 PM, Adam Pritchard < >>>>> [email protected]> wrote: >>>>> >>>>>> I've also been working on a little log-file-following (tail -f) node >>>>>> module. >>>>>> >>>>>> https://github.com/adam-p/text-file-follower/blob/master/lib/index.coffee >>>>>> >>>>>> I need it to work on Windows, so it's cross-platform. It works okay >>>>>> already, but I still have some stuff to do. >>>>>> >>>>>> The behaviour of fs.watch is a bit sketchy. For example... >>>>>> https://github.com/joyent/node/issues/search?q=fs.watch&state=open >>>>>> >>>>>> If I didn't need/want to support Windows I'd probably use >>>>>> fs.watchFile. >>>>>> >>>>>> -- >>>>>> Job Board: http://jobs.nodejs.org/ >>>>>> Posting guidelines: >>>>>> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "nodejs" group. >>>>>> To post to this group, send email to [email protected] >>>>>> To unsubscribe from this group, send email to >>>>>> [email protected] >>>>>> For more options, visit this group at >>>>>> http://groups.google.com/group/nodejs?hl=en?hl=en >>>>>> >>>>> >>>>> -- >>>>> Job Board: http://jobs.nodejs.org/ >>>>> Posting guidelines: >>>>> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines >>>>> You received this message because you are subscribed to the Google >>>>> Groups "nodejs" group. >>>>> To post to this group, send email to [email protected] >>>>> To unsubscribe from this group, send email to >>>>> [email protected] >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/nodejs?hl=en?hl=en >>>>> >>>> >>>> -- >>>> Job Board: http://jobs.nodejs.org/ >>>> Posting guidelines: >>>> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines >>>> You received this message because you are subscribed to the Google >>>> Groups "nodejs" group. >>>> To post to this group, send email to [email protected] >>>> To unsubscribe from this group, send email to >>>> [email protected] >>>> For more options, visit this group at >>>> http://groups.google.com/group/nodejs?hl=en?hl=en >>>> >>> >>> -- >>> Job Board: http://jobs.nodejs.org/ >>> Posting guidelines: >>> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines >>> You received this message because you are subscribed to the Google >>> Groups "nodejs" group. >>> To post to this group, send email to [email protected] >>> To unsubscribe from this group, send email to >>> [email protected] >>> For more options, visit this group at >>> http://groups.google.com/group/nodejs?hl=en?hl=en >>> >> >> -- >> Job Board: http://jobs.nodejs.org/ >> Posting guidelines: >> https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines >> You received this message because you are subscribed to the Google >> Groups "nodejs" group. >> To post to this group, send email to [email protected] >> To unsubscribe from this group, send email to >> [email protected] >> For more options, visit this group at >> http://groups.google.com/group/nodejs?hl=en?hl=en >> > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
