NAME

snooze —

run a command at a particular time

SYNOPSIS

snooze [-nv] [-t timefile] [-T timewait] [-R randdelay] [-J jitter] [-s slack] [-d day] [-m mon] [-w wday] [-D yday] [-W yweek] [-H hour] [-M min] [-S sec] command ...

DESCRIPTION

snooze waits until a particular time and then runs a command. Together with a service supervision system such as runsv(8), this can be used to replace cron(8).

The options are as follows:

-n: Dry run: print the next 5 times the command would run and exit.
-v: Verbose: print scheduled (and rescheduled) times.
-t, -T: See below, TIMEFILES.
-R: Delay determination of scheduled time randomly up to randdelay seconds later.
-J: Delay execution randomly up to jitter seconds later than scheduled time.
-s: Commands are executed even if they are slack (default: 60) seconds late.

The durations randdelay and slack and timewait are parsed as seconds, unless a postfix of m for minutes, h for hours, or d for days is used.

The remaining arguments are patterns for the time fields:

-d: day of month
-m: month
-w: weekday (0-7, sunday is 0 and 7)
-D: day of year (1..366)
-W: ISO week of year (1..53)
-H: hour
-M: minute
-S: second

The following syntax is used for these options:

-d 3: exact match: run on the 3rd
-d 3,10,27: alternation: run on 3rd, 10th, 27th
-d 1-5: range: run on 1st, 2nd, 3rd, 4th, 5th
-d *: star: run every day
-d /5: repetition: run on 5th, 10th, 15th, 20th, 25th, 30th day
-d 2/5: shifted repetition: run on 7th, 12th, 17th, 22nd, 27th day

and combinations of those, e.g. -d 1-10,15/5,28.

The defaults are -d* -m* -w* -D* -W* -H0 -M0 -S0, that is, every midnight.

Note that all patterns need to match (contrary to cron(8) where either day of month or day of week matches), so -w5 -d13 only runs on Friday the 13th.

If snooze receives a SIGALRM signal, the command is immediately executed.

TIMEFILES

Optionally, you can keep track of runs in time files, using -t:

When -T is passed, execution will not start earlier than the mtime of timefile plus timewait seconds.

When -T is not passed, snooze will start finding the first matching time starting from the mtime of timefile, and taking slack into account. (E.g. -H0 -s 1d -t timefile will start an instant execution when timefile has not been touched today, whereas without -t this would always wait until next midnight.)

If timefile does not exist, it will be assumed outdated enough to ensure earliest execution.

snooze does not update the timefiles, your job needs to do that! Only mtime is looked at, so touch(1) is good.

EXIT STATUS

The snooze utility exits 0 on success, and >0 if an error occurs.

The command is run using exec, so its exit status gets propagated to the parent.

If no command was given, snooze just returns with status 0.

AUTHORS

Leah Neukirchen <leah@vuxu.org>

LICENSE

snooze is in the public domain.

To the extent possible under law, the creator of this work has waived all copyright and related or neighboring rights to this work.

http://creativecommons.org/publicdomain/zero/1.0/