crontab

README

Crontab

A processor run in goroutine like linux crontab.

Timed execution crontab

Field name	Mandatory?	Allowed values	Allowed special characters
Seconds	No	0-59	* / , -
Minutes	Yes	0-59	* / , -
Hours	Yes	0-23	* / , -
Day of month	Yes	1-31	* / , - L W
Month	Yes	1-12 or JAN-DEC	* / , -
Day of week	Yes	0-6 or SUN-SAT	* / , - L #
Year	No	1970–2099	* / , -

Asterisk ( * )

The asterisk indicates that the cron expression matches for all values of the field. E.g., using an asterisk in the 4th field (month) indicates every month.

Slash ( / )

Slashes describe increments of ranges. For example 3-59/15 in the minute field indicate the third minute of the hour and every 15 minutes thereafter. The form */... is equivalent to the form "first-last/...", that is, an increment over the largest possible range of the field.

Comma ( , )

Commas are used to separate items of a list. For example, using MON,WED,FRI in the 5th field (day of week) means Mondays, Wednesdays and Fridays.

Hyphen ( - )

Hyphens define ranges. For example, 2000-2010 indicates every year between 2000 and 2010 AD, inclusive.

L

L stands for "last". When used in the day-of-week field, it allows you to specify constructs such as "the last Friday" (5L) of a given month. In the day-of-month field, it specifies the last day of the month.

W

The W character is allowed for the day-of-month field. This character is used to specify the business day (Monday-Friday) nearest the given day. As an example, if you were to specify 15W as the value for the day-of-month field, the meaning is: "the nearest business day to the 15th of the month."

So, if the 15th is a Saturday, the trigger fires on Friday the 14th. If the 15th is a Sunday, the trigger fires on Monday the 16th. If the 15th is a Tuesday, then it fires on Tuesday the 15th. However if you specify 1W as the value for day-of-month, and the 1st is a Saturday, the trigger fires on Monday the 3rd, as it does not 'jump' over the boundary of a month's days.

The W character can be specified only when the day-of-month is a single day, not a range or list of days.

The W character can also be combined with L, i.e. LW to mean "the last business day of the month."

Hash ( # )

# is allowed for the day-of-week field, and must be followed by a number between one and five. It allows you to specify constructs such as "the second Friday" of a given month.

Documentation

Overview

Package crontab provides a ticker manager like linux crontab.

Index

• Constants
• Variables
• type Cron
  • func New(name string) Cron
• type Crontab
• type Job
• type JobBefore
• type JobFailed
• type JobFinish
• type JobSucceed
• type Strategy
• type Worker

Constants

const (
	// EveryMinute
	// is an alias for src.EveryMinute strategy.
	EveryMinute = src.EveryMinute

	// EveryHour
	// is an alias for src.EveryHour strategy.
	EveryHour = src.EveryHour
)

Variables

var (
	// NewWorker
	// is an alias for src.Worker creator.
	NewWorker = src.NewWorker
)

Types

type Cron

type Cron = src.Cron

Cron is an alias for src.Cron.

func New

func New(name string) Cron

New creates a crontab with given name.

type Crontab

type Crontab = src.Crontab

Crontab is an alias for src.Crontab.

type Job

type Job = src.Job

Job is an alias for src.Job.

type JobBefore

type JobBefore = src.JobBefore

JobBefore is an alias for src.JobBefore.

type JobFailed

type JobFailed = src.JobFailed

JobFailed is an alias for src.JobFailed.

type JobFinish

type JobFinish = src.JobFinish

JobFinish is an alias for src.JobFinish.

type JobSucceed

type JobSucceed = src.JobSucceed

JobSucceed is an alias for src.JobSucceed.

type Strategy

type Strategy = src.Strategy

Strategy is an alias for src.Strategy.

type Worker

type Worker = src.Worker

Worker is an alias for src.Worker.