pcall

lua-- test.lua 文件
local status, err = pcall(function()
    a = 2 / 0  -- 这里会发生运行错误
end)

if not status then
    print("An error occurred: " .. err)
end

lua-- file_reader.lua 文件
function readFile(filename)
    local file = io.open(filename, "r")
    if not file then
        return nil, "Failed to open file: " .. filename
    end
    local content = file:read("*a")
    file:close()
    return content
end

function convertToNumber(str)
    local num = tonumber(str)
    if not num then
        return nil, "Failed to convert to number: " .. str
    end
    return num
end

local status, content = pcall(readFile, "data.txt")
if not status then
    print(content)
    return
end

local status, number = pcall(convertToNumber, content)
if not status then
    print(number)
else
    print("The number is: " .. number)
end