HCRON
Last modified by Admin on 2020/11/07 16:42
What is hcron?
hcron is a periodic command scheduler along the lines of the ubiquitous cron–but with unique features.
hcron scales easily from a handful of events to many thousands:
What Sets hcron Apart?
Many features are unique to hcron:
- events are named and organized hierarchically
- events are defined individually (by file)
- key=value based event definition
- events are composable (include directive)
- template events (template_event field)
- event chaining of one or more events (next_event and failover_event fields)
- powerful and concise variable manipulation
- events do not get clobbered during system reinstalls
- network-oriented rather than host-oriented
- event tree document generation tool (see Generating Event Tree Documentation)
- on-demand activation of existing events
Comparing cron/crontab to hcron
crontab entry:
# hello_dolly
0 11,21 * 2-12/2 * ssh exechost.abc.xyz 'echo "hello dolly" > /tmp/hello_dolly'; mail -s done Mister.Big@mailhost.abc.xyz
0 11,21 * 2-12/2 * ssh exechost.abc.xyz 'echo "hello dolly" > /tmp/hello_dolly'; mail -s done Mister.Big@mailhost.abc.xyz
hcron event file (called hello_dolly):
as_user=
host=exechost.abc.xyz
command=echo "hello dolly" > /tmp/hello_dolly
notify_email=Mister.Big@mailhost.abc.xyz
notify_message=done
when_month=2-12/2
when_day=*
when_hour=11,21
when_minute=0
when_dow=2
host=exechost.abc.xyz
command=echo "hello dolly" > /tmp/hello_dolly
notify_email=Mister.Big@mailhost.abc.xyz
notify_message=done
when_month=2-12/2
when_day=*
when_hour=11,21
when_minute=0
when_dow=2
Using hcron means never needing to check the crontab man page to remember the field order. But there is more to hcron than a key=value approach.
See the Documentation for more.