add program updating script

cc-tweaked/scripts/update.lua

@@ -0,0 +1,56 @@
+-- usage : update <url> <program>
+--
+-- downloads
+
+local program = ...
+
+local function new_config(name)
+    local path = "/etc/" .. name
+
+    local function read_key_in_line(line, key)
+        local prefix = key .. ":"
+        local prefix_len = string.len(prefix)
+        local actual = string.sub(line, 0, prefix_len)
+        if not (prefix == actual) then return nil end
+        local value = string.sub(line, prefix_len + 1)
+        return value
+    end
+
+    local function get(key, default)
+        local file = fs.open(path, "r")
+        if file == nil then return default end
+        while true do
+            local line = file.readLine()
+            if line == nil then return default end
+            local value = read_key_in_line(line, key)
+            if not (value == nil) then return value end
+        end
+    end
+
+    return { get = get }
+end
+
+local function main()
+    if program == nil then
+        print("Usage: update <program>")
+        return
+    end
+
+    local url = new_config("update").get("url", "http://cc.epitls.fr")
+    local url_ = url .. "/" .. program
+    local response = http.get(url_)
+    if (response == nil) or (type(response) == "string") then
+        print("HTTP Request to", url_, " failed :", response)
+        return
+    end
+
+    local content = response.readAll()
+    local path = "./" .. program
+    if fs.exists(path) then fs.delete(path) end
+    local file = fs.open(path, "w")
+    file.write(content)
+
+    print("Updated program", program)
+end
+
+main()