> The new idea is to read the required command instructions, work out which command needs to be executed next, and then sleep until the inferred time has arrived. On waking the commands are run, and the time of the next command is computed.
> Each user looks after his own files in his own directory. He can use more than one to break up complicated cron specifications. Each user can run his own daemon. This removes the need for suid programs to manipulate the crontabs, and eliminates many security concerns that surround all existing cron programs.
> Vixie cron is implemented in 4500 lines of C code; mcron is 1500 lines of scheme, despite the fact that it offers many more features and much more flexibility, and complete compatibility with Vixie cron.
This is a nice misrepresentation. Your Vixie cron example offloads the day of week check to `date`. I'm sure there are examples where mcron syntax is superior to anacron as well.
I didn't know about mcron until this post either, but I find it super frustrating when people dismiss tools, ideas, or people simply because they don't conform to familiar patterns.
This is awesome! I have really been impressed with gnu's use of guile, and I really like how much more quickly iteration is than many other gnu projects. For those heavy cron users, mcron (guile based cron replacement) has been my favorite so far.
With a good deamon manager, we're one step closer to HURD!
I don't really understand. What could I do with this that I couldn't do with cron? Or is it that somebody who can't use cron could use this? Or that this is more reliable than cron?
Sure but there are tons of simple cron alternatives with better syntax that don't need systemd (such as fcron). In fact, Mcron from the OP can be configured using Scheme.
The cron syntax is used by a bunch of other things as well, e.g k8s cronjobs so sites like this are still useful even if you aren't using a traditional cron
> It is hugely more convenient and usable than cron. Once you have it, you immediately spot lots of opportunities to factor systems into scheduled jobs that you might have avoided doing if it meant you had to deal with cron.
That's actually pretty interesting. Can you give a few examples that fall out of having a more fine grained (millisecond) resolution?
I think you should check out mcron, which is basically cron redone but in GNU guile (scheme) with more features. I think it fails some of your requirements (the syntax can be a bit more to wrap ones head around than standard cron), but it is powerful and seems promising.
Their website[1] shows something that looks nearly identical to the MacOS default calendar app (edit: which is a good design to take inspiration from) but no list of features or much else of substance.
I think you are just more used to creating a VM and running crons from there. The other alternatives aren't necessarily time consuming, you just aren't used to them
Not sure what the OP intended as the context around this submission, but here's some more info:
Latest version 1.1.1 released 2018-04-08 [1][2]. Previous version was 1.1 on 2018-03-19, and the one before that dates to 2010-06-13 [2].
This is a job scheduler compatible with vixie-cron [3], but written in Guile Scheme. Entries in a crontab file can be the traditional format, or snippets of Guile. There's a whitepaper from 2003 [4] and up-to-date documentation [5] that explain the rationale and usage.
reply