cron-cpp

What is this ?

This is a cron libriary write by c++ .

Support Format :

┌─────────────sec ( 0 - 59 ) 
| ┌───────────── min (0 - 59) 
| │ ┌────────────── hour (0 - 23)
| │ │ ┌─────────────── day of month (1 - 31)
| │ │ │ ┌──────────────── month (1 - 12)
| │ │ │ │ ┌───────────────── day of week (0 - 6) (0 to 6 are Sunday to Saturday, or use names; )
| │ │ │ │ │
| │ │ │ │ │
* * * * * *   

Field name	Mandatory?	Allowed values	Allowed special characters
Minutes	Yes	0-59	* , - ?
Minutes	Yes	0-59	* , - ?
Hours	Yes	0-23	* , - ?
Day of month	Yes	1-31	* , - ?
Month	Yes	1-12 or JAN-DEC	* , - ?
Day of week	No	0-6 or SUN-SAT	* , - ?

Special pre-defines

"@yearly" or "@annually"
"@monthly"
"@weekly"
"@daily" or "@midnight"
"@hourly"
"@every hh:mm:ss"

Basic usage

Basic defines

• Namespace : Cron
• Basic swap for boost library :

typedef boost::asio::io_service IOService;

• Job function

typedef std::function<void()> Job;

• Log level and log function :

enum CronLogLevel {
  Unknow = 0 ,
  Info = 1,
  Debug = 2 ,
  Warning = 3 ,
  Error = 4 ,
  Fatel = 5
};

// Where Cron print it's logs
typedef std::function<void( CronLogLevel lev ,  const std::string & string)> CronLogger;

• Cron manager class Cron .

Interfaces ( all interfaces are members of class Cron::Cron ) .

• Cron construct :

1. Cron doesn't manager IOService .
2. Cron and all jobs that Cron manager are running on this IOService .

Cron(IOService & s ,  CronLogger l)

• Cron start :

void Start();

• Cron stop :
  1. Stop interface will top Cron . No more jobs will triggered .
  2. Jobs that already triggered will not be stoped .

void Stop();

• Add a job into cron
  1. AddJob is thread-safe inteface .
  2. you can call AddJob anytime .
  3. return int is a handler of this job, use it to remove this job .

int AddJob(const std::string & pattern , Job j);

• Remove a specific job :. 1 RemoveJob is thread-safe inteface . 2. you can call RemoveJob anytime .

void RemoveJob(int id)

Example

#include "cron.h"
#include <thread>
#include <iostream>
int main() {
    Cron::IOService ios;
    Cron::Cron cron(ios, [](Cron::CronLogLevel lev , const std::string & log) {
      std::cout<<"Log lev : "<<lev<<" -- log message : "<<log<<std::endl;
    });
    cron.AddJob("* * * * *" , []() {
      std::cout<<"Hello worLd"<<std::endl;
    });
    cron.Start();
    ios.run();
    return 0 ;
}

Used 3rd libriary

1. boost
2. UnitTest++ ( only if you want to compiler test code )

Support platform

Any platform that CMake support and if you want to edit CMakeLists.txt for it.

Why does I write this ?

At first I hope to find a cron libriary for c++ language , but after searching from github ， it seems no highly stared repository of c++ cron libriary . Instead I find https://github.com/robfig/cron ,a cron libriary of Go language which has hundrends of stars . So I decided to rewrite it by c++ .

Referecnce

###cron language https://en.wikipedia.org/wiki/Cron

rofig/cron

https://github.com/robfig/cron