lcron

[Lev <leventelist@...>]

Hi list,


So I've written a small Lua library that has similar funcionality as cron(8).

The question is how can I share this with the comunity? Shall I create a
github repo? Is there any central database for these?

Thanks,
Lev

-- 
73 de HA5OGL
Op.: Levente

local lcron = {
  __VERSION     = 'lcron.lua 1.1.0',
  __DESCRIPTION = "Levente's cron for lua",
  __URL         = 'http://levente.logonex.eu/',
  __LICENSE     = [[
    Copyright (c) 2014-2016 Levente Kovacs

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to
    permit persons to whom the Software is furnished to do so, subject to
    the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  ]]
}

local function eval_field (num, pattern)

	local lp, rp, l, r

	if pattern==nil then
		return true
	end

	if pattern=="*" then
		return true
	end

	local ll = 0
	local subpattern
	local stepp
	local step

	while true do
		step=nil
		lr = string.find(pattern, ",", ll)
		if lr ~=nil then
			subpattern = string.sub(pattern, ll, lr-1)
		else
			subpattern = string.sub(pattern, ll)
		end

		stepp=string.find(subpattern, "/", ll)
		if stepp~=nil then
			step=tonumber(string.sub(subpattern, stepp+1))
			subpattern = string.sub(subpattern, 0, stepp-1)
		end

		local val=nil
		if type(subpattern)=='number' then
			val=subpattern
		elseif type(subpattern)=='string' then
			val=tonumber(subpattern)
		end

		if val~=nil then
			if val==num then
				return true
			elseif step~=nil and ((num-val)%step)==0 then
				return true
			end
		end

		lp,rp=string.find (subpattern, "-")
		if lp~=nil then
			l=tonumber(string.sub(subpattern, 1, lp-1))
			r=tonumber(string.sub(subpattern, rp+1))
			if type(l)=='nil' then return false end
			if type(r)=='nil' then return false end

			if l<=num and num<=r then
				if step==nil then
					return true
				elseif ((num-l)%step)==0 then
					return true
				end
			end

		end
		if lr==nil then
			break
		end
		ll=lr+1
	end

	return false
end

function lcron.at(tab)

	local bdt=os.date("*t")

	if type(tab)~='table' then
		return false
	end

	--Convert wday to ISO8601 weekday format (Monday=1, Sunday=7), so one can specify weekend by '6-7'
	local wday=bdt.wday-1
	if wday==0 then 
		wday=7
	end

	if not eval_field(bdt.year, tab.year) then
		return false
	elseif not eval_field(bdt.month, tab.month) then
		return false
	elseif not eval_field(bdt.day, tab.dom) then
		return false
	elseif not eval_field(wday, tab.dow) then
		return false
	elseif not eval_field(bdt.hour, tab.hour) then
		return false
	elseif not eval_field(bdt.min, tab.min) then
		return false
	end

	return true
end

function lcron.cron(tab)

	local lr
	local ll
	local i=0
	local t={}

	ll=0

	while true do

		lr = string.find(tab, "%s+", ll)

		if lr ~=nil then
			field = string.sub(tab, ll, lr-1)
		else
			field = string.sub(tab, ll)
		end

		if i==0 then
			t.min=field
		elseif i==1 then
			t.hour=field
		elseif i==2 then
			t.dom=field
		elseif i==3 then
			t.month=field
		elseif i==4 then
			t.dow=field
		end

		if lr==nil then
			break
		end
		ll=lr+1
		i=i+1
	end

	t.year="*"

	return lcron.at(t)

end

return lcron

local lcron = require 'lcron'

local data = {year="2017,2010-2030/2, 2019", month=5, dow='*', dom='25', hour="1-22", min='*'}

if lcron.at(data) then
	print ("Match! :-)")
else
	print ("No match :-(")
end

if lcron.cron("* 7 25 5 1-6") then
	print ("Match! :-)")
else
	print ("No match :-(")

end