ONYX shell - unix-like shell simulator - version for Mobile Lua

onyx-mobile.lua

-- VERSION FOR MOBILE LUA
----
-- Table FS
----
-- an unix-like filesystem simulation on lua tables
-- by Severak 2012
-- license: WTFPL
----

-- documentation will come later....
function tDir(t)
	for k,v in pairs(t) do
		if type(v)=="table" then
			v[".."]=t
		end
	end
	t["."]=t
	return t
end

function TableFS(tree, startPath)
	startPath = startPath or "/"
	local state={}
	local tfs={}
	
	function walk(d, path)
		local current=d
		for name in path:gmatch("([^/]+)") do
			if type(current[name])=="table" then
				current=current[name]
			elseif current[name] then
				return current[name]
			else
				return nil
			end
		end
		return current
	end
	
	state.root=tree
	state.wd=walk(state.root,startPath)
	
	tfs.load=function(path)
		if string.sub(path,1,1)=="/" then
			return walk(state.root, string.sub(path,2))
		else
			return walk(state.wd,path)
		end
	end
	
	tfs.save=function(path,data)
		local a,b=string.match(path,"(.+)/([^/]+)")
		local dir=nil
		local name=nil
		if a and b then
			dir=tfs.load(a)
			name=b
		else
			dir=state.wd
			name=path
		end
		dir[name]=data
	end
	
	tfs.dir=function(path)
		path=path or "."
		local cd=tfs.load(path)
		if not (type(cd)=="table") then
			error(string.format("%s is not dir"),path)
		end
		local listing={}
		for k,v in pairs(cd) do
			listing[#listing+1]=k
		end
		table.sort(listing)
		local i=0
		local n=#listing
		return function()
			i=i+1
			if i <= n then return listing[i] end
		end
	end
	
	tfs.chdir=function(path)
		local newDir=tfs.load(path)
		if newDir then
			if type(newDir)=="table" then
				state.wd=newDir
				return true
			end
			return nil, "This isn't dir." 
		end
		return nil, "Path goes to nowhere"
	end
	
	tfs.mkdir=function(name)
		if state.wd[name] then
			return nil, "Directory already exists."
		else
			state.wd[name]={}
			state.wd[name][".."]=state.wd
			state.wd[name]["."]=state.wd[name]
		end
	end
	
	tfs.pwd=function()
		curr=state.wd
		local names={}
		while curr[".."] do
			prev=curr
			curr=curr[".."]
			for k,v in pairs(curr) do
				if v==prev then
					table.insert(names,1,k)
				end
			end
		end
		return "/" .. table.concat(names,"/")
	end
	
	return tfs
end

----
-- ONYX shell
----
-- unix-like shell simulator
-- by Severak 2012
-- license WTFPL
----
command={}
command["ver"]=function()
	return "ONYX v 1.0"
end
--command["exit"]=function() os.exit() end
command["echo"]=function(argz)
	return table.concat(argz," ")
end
command["ls"]=function(argz)
	local out={}
	local dir=argz[1] or "."
	if not(type(tfs.load(dir))=="table") then
		print(string.format("%s is not a dir.", dir))
		return ""
	end
	for file in tfs.dir(dir) do
		out[#out+1]=file
	end
	return table.concat(out,"\n")
end
command["cd"]=function(argz)
	local ok,err=tfs.chdir(argz[1] or ".")
	if not ok then
		print("-onyx: ",err)
	end
end

command["pwd"]=function(argz)
	return tfs.pwd()
end

command["mkdir"]=function(argz)
	local ok,err=tfs.mkdir(argz[1] or ".")
	if ok then
		return 0
	else
		print(err)
	end
end

command["rmrf"]=function(argz)
	if #argz>0 then
		tfs.save(argz,nil)
	end
end

function splitWords(sentence)
	local ret={}
	for word in sentence:gmatch("([^%s]+)") do
		ret[#ret+1]=word
	end
	return ret
end

local tree=tDir{
	home=tDir{
		help="Work with it as you will work with unix.",
		examples=tDir{
			a="echo ok|reverse",
			b="cat /doc/readme",
			c="ls>dir.txt",
			d="echo ok|reverse|tee reversed.txt|reverse>normal.txt"
		}
	},
	doc=tDir{
		readme="There is no readme today\n:-("
	},
	bin=tDir{},
	dev=tDir{}
}

devMT={
	__index=function(dir,file)
		if file=="random" then
			return math.random(255)
		elseif file=="null" then
			return ""
		end
	end,
	__newindex=function(dir,file,data)
		if file=="null" or file=="random" then
			return nil
		else
			rawset(dir,file,data)
		end
	end
}

setmetatable(tree["dev"],devMT)

tfs=TableFS(tree,"home")

tfs.save("/bin/cat", function(argz,stdin)
	local out={}
	if #argz>0 then
		for _,name in pairs(argz) do
			local data,err=tfs.load(name)
			if type(data)=="table" then
				print(string.format("cat: %s: Is directory",name))
			elseif data then
				out[#out+1]=tostring(data)
			else
				print(string.format("cat: %s: %s",name,err or "File not found!"))
			end
		end
	else	
		out[#out+1]=input.get()
	end
	return table.concat(out,"\n")
end)

tfs.save("/bin/reverse", function(argz,stdin)
	return string.reverse(stdin or "")
end)

tfs.save("/bin/tee", function(argz,stdin)
	for _,name in pairs(argz) do
		tfs.save(name,stdin)
	end
	return stdin
end)

tfs.save("/bin/help", function()
	print("Use it like unix.")
	print("There is no other help...")
end)

function processPipe(cmds)
	local out=""
	for stdin in string.gmatch(cmds,"([^|]+)") do
		local args=splitWords(stdin)
		local cmd=table.remove(args,1)
		if command[cmd] then
			out=command[cmd](args)
		else
			local fun=tfs.load("/bin/"..cmd)
			if type(fun)=="function" then
				out=fun(args,out)
			else
				print(string.format("An attemp to call %s (not a function)",cmd))
				break
			end
		end
	end
	return out or ""
end


function main()
	while true do
		local outfile=false
		local stdin=input.get()
		if stdin=="" then
			freeze()
		else
			if stdin=="exit" then
				break
			end
			if string.match(stdin,"(.+)>(.+)") then
				stdin,outfile=string.match(stdin,"(.+)>(.+)")
			end
			local out=processPipe(stdin)
			if not(out=="") then
				if outfile then
					tfs.save(outfile,out)
				else
					print(out)
				end
			end
		end
	end
end

main()