lua 字符串处理

local function strFormatSub(strTmp,strSub_f,strSub_b)
	local _,i = string.find(strTmp,strSub_f)
	local j = string.find(strTmp,strSub_b)
	if i == nil or j == nil then
		return nil
	end	
	return string.sub(strTmp,i + 1,j - 1)	
end
--[[
--截取一段子字符串，针对xml文件
local strSub_f = "<string>"
local strSub_b = "</string>"
local strtest = "<string>aaabbb</string>"
print(strFormatSub(strtest,strSub_f,strSub_b))
--rs: aaabbb
--]]
local function strFormatGotOldPath(strTmp,strOldFileSuf)
	local i,j = string.find(strTmp,"/")
	if i == nil or j == nil then
		return ""
	end
	local subStr = string.sub(strTmp, 0, i - 1)
	strTmp = string.sub(strTmp, i, string.len(strTmp))
	return subStr .. strOldFileSuf .. strTmp
end
--[[
--字符串中间添加子字符串
local strtest = "aaabbb/a.txt"
local strOldFileSuf = "Old"
print(strFormatGotOldPath(strtest,strOldFileSuf))
--rs: aaabbbOld/a.txt
--]]


local function strFormatDealSpecialChar(str)
	local len = string.len(str)
	local specialChars = {"%+","%-","%."}
	local specialCharsReplace = {"%%+","%%-","%%."}
	local newstr = str
	for index,item in pairs(specialChars) do
		newstr = string.gsub(newstr, item, specialCharsReplace[index])
	end
	--print(newstr)
	return newstr
end
--转换特殊字符，文件中读取的字符串匹配时需要转换
--local str = "lock-woo+d_2ui.png"
--local strss = [[adfadasdflock-woo+d_2ui.pngagdsedgg]]
--print(string.find(strss,str))
--local newStr = strFormatDealSpecialChar(str)
--print(newStr)
--print(string.find(strss,newStr))
--[[
rs: 
nil
lock%-woo%+d_2ui%.png
10	27
--]]