added package installer

packageinstall.lua

@@ -0,0 +1,143 @@
+--[[ 
+	Dig Program Installer
+	Author: Hion-V
+	Version: 1.0
+	Lines of Code: 161; Characters: 5541
+]]
+
+-- INSTALL PACKAGE INFO
+packageName = "dig"
+packageURL = "https://git.subsonics.nl/pootercraft/dig/raw/branch/master/bin/dig"
+packageBinPath = "/bin/"
+packageFilename = "dig"
+
+-- Read arguments
+args = {...}
+
+-- FILE MANIPULATION FUNCTIONS --
+--[[ Checks if file exists
+	@param String filepath: Filepath to check
+	@return boolean: Does the file exist?
+--]]
+function file_exists(filepath)
+	local f=io.open(filepath,"r")
+	if f~=nil then 
+		io.close(f) 
+		return true 
+	else 
+		return false 
+	end
+end
+
+--[[ Stores a file in a desired location
+	@param String filepath: Filepath where to create file (if file already exists, it gets overwritten)
+	@param String content: Content to store in file
+--]]
+function storeFile(filepath,content)
+	writefile = fs.open(filepath,"w")
+	writefile.write(content)
+	writefile.close()
+end
+
+--[[ Reads a file from a desired location
+	@param String filepath: Filepath to the file to read
+	@param String createnew: (Optional) Content to store in new file and return if file does not exist. Can be nil.
+	@return String|boolean content|error: Content of the file; If createnew is nil and file doesn't exist boolean false is returned
+--]]
+function readFile(filepath,createnew)
+	readfile = fs.open(filepath,"r")
+	if readfile == nil then
+		if not (createnew==nil) then
+			storeFile(filepath,createnew)
+			return createnew
+		else
+			return false
+		end
+	end
+	content = readfile.readAll()
+	readfile.close()
+	return content
+end
+
+--[[ Stores a table in a file
+	@param String filepath: Filepath where to create file (if file already exists, it gets overwritten)
+	@param Table data: Table to store in file
+--]]
+function storeData(filepath,data)
+	storeFile(filepath,textutils.serialize(data):gsub("\n",""))
+end
+
+--[[ Reads a table from a file in a desired location
+	@param String filepath: Filepath to the file to read
+	@param boolean createnew: If true, an empty table is stored in new file and returned if file does not exist.
+	@return Table|boolean content|error: Table thats stored in the file; If createnew is false and file doesn't exist boolean false is returned
+--]]
+function readData(filepath,createnew)
+	if createnew then
+		return textutils.unserialize(readFile(filepath,textutils.serialize({}):gsub("\n","")))
+	else
+		return textutils.unserialize(readFile(filepath,nil))
+	end
+end
+
+-- HTTP FETCH FUNCTIONS --
+--[[ Gets result of HTTP URL
+	@param String url: The desired URL
+	@return Table|boolean result|error: The result of the request; If the URL is not reachable, an error is printed in the terminal and boolean false is returned
+--]]
+function gethttpresult(url)
+	if not http.checkURL(url) then
+		print("ERROR: Url '" .. url .. "' is blocked in config. Unable to fetch data.")
+		return false
+	end
+	result = http.get(url)
+	if result == nil then
+		print("ERROR: Unable to reach '" .. url .. "'")
+		return false
+	end
+	return result
+end
+
+--[[ Download file HTTP URL
+	@param String filepath: Filepath where to create file (if file already exists, it gets overwritten)
+	@param String url: The desired URL
+	@return nil|boolean nil|error: nil; If the URL is not reachable, an error is printed in the terminal and boolean false is returned
+--]]
+function downloadfile(filepath,url)
+	result = gethttpresult(url)
+	if result == false then 
+		return false
+	end
+	storeFile(filepath,result.readAll())
+end
+
+-- MISC HELPER FUNCTIONS --
+--[[ Checks wether a String starts with another one
+	@param String haystack: String to check wether is starts with another one
+	@param String needle: String to check wether another one starts with it
+	@return boolean result: Wether the firest String starts with the second one
+]]--
+function startsWith(haystack,needle)
+	return string.sub(haystack,1,string.len(needle))==needle
+end
+
+-- MAIN PROGRAMM --
+if (args[1]=="install") or (args[1]==nil) then
+	print("[Installer] Installing",packageName)
+	if downloadfile(packageBinPath..PackageFilename,packageURL)==false then
+		return false
+	end
+	print("[Installer] Successfully installed '"..packagename.."'!")
+elseif args[1]=="update" then
+	print("[Installer] Updating "..packageName.."...")
+    if downloadfile("bin/dig",packageURL)==false then
+        fs.move()
+		return false
+	end
+elseif args[1]=="remove" then
+	print("[Installer] Uninstalling '"..packageName.."'...")
+	fs.delete("/bin/dig")
+	print("[Installer] So long, and thanks for all the fish!")
+else
+	print("[Installer] Invalid argument: " .. args[1])
+end