made the vt100 emulator not choke on most complicated inputs

build.sh

@@ -2,4 +2,8 @@
 rm -r target/*
 mkdir target
 lua luapreproc.lua module/init.lua target/init.lua
+echo _OSVERSION=\"PsychOS 2.0a1-$(git rev-parse --short HEAD)\" > target/version.lua
+cat target/version.lua target/init.lua > target/tinit.lua
+mv target/tinit.lua target/init.lua
 cp -r exec/ service/ lib/ target/
+lua finddesc.lua $(find module/ -type f) $(find lib/ -type f) > apidoc.md

exec/init.lua

@@ -1,12 +1,12 @@
 xpcall(function()
+os.setenv("PWD","/boot")
 os.spawnfile("/boot/service/getty.lua")
 coroutine.yield()
 for k,v in pairs(fs.list("/dev/")) do
  if v:sub(1,3) == "tty" then
   dprint(tostring(io.input("/dev/"..v)))
   dprint(tostring(io.output("/dev/"..v)))
-  io.write("PsychOS v2.0a1 - ")
-  print(tostring(math.floor(computer.totalMemory()/1024)).."K RAM")
+  print(_OSVERSION.." - "..tostring(math.floor(computer.totalMemory()/1024)).."K RAM")
   os.spawnfile("/boot/exec/shell.lua")
  end
 end

exec/shell.lua

@@ -3,25 +3,7 @@ local shenv = {}
 function shenv.quit()
  os.setenv("run",nil)
 end
-function shenv.cd(p)
- if p:sub(1,1) == "/" then
-  if fs.list(p) then
-   os.setenv("PWD",p)
-  else
-   print("no such directory: "..p)
-  end
- else
-  local np = {}
-  for k,v in pairs(fs.segments(os.getenv("PWD").."/"..p)) do
-   if v == ".." then
-    np[#np] = nil
-   else
-    np[#np+1] = v
-   end
-  end
-  os.setenv("PWD","/"..table.concat(np,"/"))
- end
-end
+shenv.cd = os.chdir
 setmetatable(shenv,{__index=function(_,k)
  if _G[k] then
   return _G[k]

module/init.lua

@@ -1,6 +1,7 @@
 --#include "module/chatbox-dprint.lua"
 --#include "module/syslog.lua"
 --#include "module/sched.lua"
+--#include "module/osutil.lua"
 --#include "module/fs.lua"
 --#include "module/newio.lua"
 --#include "module/devfs.lua"

module/osutil.lua

@@ -0,0 +1,18 @@
+function os.chdir(p) -- changes the current working directory of the calling process to the directory specified in *p*, returning true or false, error
+ if not (p:sub(1,1) == "/") then
+  local np = {}
+  for k,v in pairs(fs.segments(os.getenv("PWD").."/"..p)) do
+   if v == ".." then
+    np[#np] = nil
+   else
+    np[#np+1] = v
+   end
+  end
+  p = "/"..table.concat(np,"/")
+ end
+ if fs.exists(p) and fs.list(p) then
+  os.setenv("PWD",p)
+ else
+  return false, "no such directory"
+ end
+end

module/vt-task.lua

@@ -1,6 +1,6 @@
 do
 --#include "module/vt100.lua"
-function vtemu(gpua,scra)
+function vtemu(gpua,scra) -- creates a process to handle the GPU and screen address combination *gpua*/*scra*. Returns read, write and "close" functions.
  local gpu = component.proxy(gpua)
  gpu.bind(scra)
  local write = vt100emu(gpu)

module/vt100.lua

@@ -61,16 +61,16 @@ function vt100emu(gpu) -- takes GPU component proxy *gpu* and returns a function
      cx, cy = tonumber(tx), tonumber(ty)
      mode = "n"
     elseif cc == "A" then -- cursor up
-     cy = cy - tonumber(cs) or 1
+     cy = cy - (tonumber(cs) or 1)
      mode = "n"
     elseif cc == "B" then -- cursor down
-     cy = cy + tonumber(cs) or 1
+     cy = cy + (tonumber(cs) or 1)
      mode = "n"
     elseif cc == "C" then -- cursor right
-     cx = cx + tonumber(cs) or 1
+     cx = cx + (tonumber(cs) or 1)
      mode = "n"
     elseif cc == "D" then -- cursor left
-     cx = cx - tonumber(cs) or 1
+     cx = cx - (tonumber(cs) or 1)
      mode = "n"
     elseif cc == "h" and lc == "7" then -- enable line wrap
      lw = true