neyuki 0.6.3

A small Lua-like scripting language implemented in Rust
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-- Where a desktop app keeps its settings, cache and secrets: counts how often
-- it has run in a settings file, and keeps a sealed token between runs.
--
--   neyuki app_storage.nyk
--   neyuki app_storage.nyk forget

local fs = require("@neyuki/fs")

const APP = "Neyuki Storage Example"

local settingsFile = fs.join(os.configDir(APP), "settings.json")
local tokenFile = fs.join(os.dataDir(APP), "token")
print("settings: " .. settingsFile)
print("cache:    " .. os.cacheDir(APP))

if os.args()[1] == "forget" then
    for _, file in { settingsFile, tokenFile } do
        if fs.exists(file) then fs.remove(file) end
    end
    print("forgotten")
    return
end

local settings = fs.exists(settingsFile) and json.decode(fs.read(settingsFile)) or { runs = 0 }
settings.runs += 1
fs.write(settingsFile, json.encode(settings, { indent = 2 }))
print(`run number {settings.runs}`)

-- The token is sealed for this user on this machine. Without an OS keychain
-- (a headless Linux machine, say) protect raises an error instead.
if fs.exists(tokenFile) then
    local ok, token = try(os.unprotect, fs.read(tokenFile))
    print(ok and `token from last time: {token}` or `cannot read the token: {token}`)
else
    local ok, sealed = try(os.protect, "token-" .. os.time())
    if ok then
        fs.write(tokenFile, sealed)
        print("stored a new token")
    else
        print("cannot protect the token: " .. sealed)
    end
end