Cron expression parsing in go

Introduction

Supports cron expressions with seconds field. A copy of CronSequenceGenerator from Spring Framework.

Installation

The import path for the package is github.com/dongfg/gocronexpr.

To install it, run:

 go get github.com/dongfg/gocronexpr

License

The package is licensed under the Apache License 2.0. Please see the LICENSE file for details.

Example

package main

import (
	"fmt"
	"github.com/dongfg/gocronexpr"
	"time"
)

func main() {
	cronExpr, err := gocronexpr.New("* * * * * *", time.Local)
	if err != nil {
		fmt.Println(err)
		return
	}

	nextTime, err := cronExpr.Next(time.Now())
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(nextTime)
}

This example will generate the following output:

2019-05-22 17:13:22 +0800 CST

Install as a command

Download from release page or install with go command:

GO111MODULE="off" go get github.com/dongfg/gocronexpr/cmd/gocronexpr

Usage:

dongfg at MacBook-Pro.local in [~]
10:42:08 $ gocronexpr
NAME:
  gocronexpr - Display the time of the next N runs base on cron expression
USAGE:
  gocronexpr <cron> [N]
OPTIONS:
  <cron>  6 fields cron expression
  [N]     next number of runs, default 5

dongfg at MacBook-Pro.local in [~]
10:42:10 $ gocronexpr "5 */5 * * * *"
1: 2021-07-14 10:45:05
2: 2021-07-14 10:50:05
3: 2021-07-14 10:55:05
4: 2021-07-14 11:00:05
5: 2021-07-14 11:05:05

dongfg at MacBook-Pro.local in [~]
10:42:15 $ gocronexpr "5 */5 * * * *" 3
1: 2021-07-14 10:45:05
2: 2021-07-14 10:50:05
3: 2021-07-14 10:55:05