Made env variables local (i.e. os.getenv/setenv will operate per process now), to avoid programs running in parallel (via piping) to interfere.

Copying env vars from last process to shell's env to avoid breaking compat. (cd.lua will still work that way, e.g.)
Closes #634.

src/main/resources/assets/opencomputers/loot/OpenOS/bin/sh.lua

@@ -266,6 +266,7 @@ local function execute(env, command, ...)
     local program, args, input, output, mode = table.unpack(commands[i])
     local reason
     threads[i], reason = process.load(program, env, function()
+      os.setenv("_", program)
       if input then
         local file, reason = io.open(shell.resolve(input))
         if not file then
@@ -304,9 +305,6 @@ local function execute(env, command, ...)
       return false, reason
     end
 
-    -- TODO needs moving of env vars into process lib/info
-    -- os.setenv("_", program)
-
     if i < #commands then
       pipes[i] = require("buffer").new("rw", memoryStream.new())
       pipes[i]:setvbuf("no")
@@ -351,6 +349,15 @@ local function execute(env, command, ...)
     end
   end
 
+  -- copy env vars from last process; mostly to ensure stuff like cd.lua works
+  local lastVars = rawget(process.info(threads[#threads]).data, "vars")
+  if lastVars then
+    local localVars = process.info().data.vars
+    for k,v in pairs(lastVars) do
+      localVars[k] = v
+    end
+  end
+
   for _, input in ipairs(inputs) do
     input:close()
   end

src/main/resources/assets/opencomputers/loot/OpenOS/boot/02_os.lua

@@ -8,8 +8,6 @@ local function env()
   -- copy parent env when first requested; easiest way to keep things
   -- like number of env vars trivial (#vars).
   local data = require("process").info().data
-  --[[ TODO breaking change; will require set to be a shell built-in and
-            may break other programs relying on setenv being global.
   if not rawget(data, "vars") then
     local vars = {}
     for k, v in pairs(data.vars or {}) do
@@ -17,7 +15,6 @@ local function env()
     end
     data.vars = vars
   end
-  --]]
   data.vars = data.vars or {}
   return data.vars
 end

src/main/resources/assets/opencomputers/loot/OpenOS/lib/process.lua

@@ -83,12 +83,17 @@ function process.running(level) -- kept for backwards compat, prefer process.inf
   end
 end
 
-function process.info(level)
-  level = level or 1
-  local process = findProcess()
-  while level > 1 and process do
-    process = process.parent
-    level = level - 1
+function process.info(levelOrThread)
+  local process
+  if type(levelOrThread) == "thread" then
+    process = findProcess(levelOrThread)
+  else
+    local level = levelOrThread or 1
+    process = findProcess()
+    while level > 1 and process do
+      process = process.parent
+      level = level - 1
+    end
   end
   if process then
     return {path=process.path, env=process.env, command=process.command, data=process.data}