1.使用正则表达式分割

 starNum =  "asd,dfg,ghj"

resultStrList = {}
	reps = ","
	--  [^,]+ 正则表达式 匹配,

    string.gsub(starNum,'[^'..reps..']+',function ( w )
        table.insert(resultStrList,w)
    end)

	print(resultStrList[1])
	print(resultStrList[2])
	print(resultStrList[3])

console：

>lua -e "io.stdout:setvbuf 'no'" "base.lua"
asd
dfg
ghj
>Exit code: 0

2.

    input = "123,456,789"
    delimiter = ","
    if (delimiter=='') then return false end
    local pos,arr = 0, {}
    for st,sp in function() return string.find(input, delimiter, pos, true) end do
        table.insert(arr, string.sub(input, pos, st - 1))
        pos = sp + 1
    end
    table.insert(arr, string.sub(input, pos))
	print(arr[1])
	print(arr[2])
	print(arr[3])

console:

123
456
789
>Exit code: 0

3.

	breakpointsStr = ","
	logStr = "123,456,12312313"
	local i = 0
    local j = 1
	t = {}
    local z = string.len(breakpointsStr)
    while true do
        i = string.find(logStr, breakpointsStr, i + 1)  -- 查找下一行
        if i == nil then
            table.insert(t, string.sub(logStr,j,-1))
            break
        end
        table.insert(t, string.sub(logStr,j,i - 1))
        j = i + z

    end
	print(t[1])
	print(t[2])
	print(t[3])

>lua -e "io.stdout:setvbuf 'no'" "base.lua"
123
456
12312313
>Exit code: 0