Fix pipes in Linux with socat

README.md

@@ -7,7 +7,7 @@ See [YouTube](https://www.youtube.com/watch?v=Q69_wmEkp-k) for an example run.
 ## Requirements
 
 * lsnes with **Lua 5.2** (do not try to build with 5.3, it does not work!)
-* inotifywait for Linux, or a fairly recent version of Windows that has PowerShell
+* socat for Linux, or a fairly recent version of Windows that has PowerShell
 * A Donkey Kong Country 2 1.1 US ROM (matching hash b79c2bb86f6fc76e1fc61c62fc16d51c664c381e58bc2933be643bbc4d8b610c)
 
 ### Windows

runner-process.lua

@@ -22,7 +22,7 @@ local speciesId = -1
 local generationIndex = nil
 
 local inputPipeName = os.getenv("RUNNER_INPUT_PIPE")
-local outputFilePath = os.getenv("RUNNER_OUTPUT_FILE")
+local outputPipeName = os.getenv("RUNNER_OUTPUT_PIPE")
 
 print('Opening input pipe '..inputPipeName)
 local inputPipe = util.openReadPipe(inputPipeName)
@@ -31,16 +31,13 @@ if inputPipe == nil then
 end
 print('Opened input pipe '..inputPipeName)
 
-print('Opening output file '..outputFilePath)
-local outputFile = nil
-while outputFile == nil do
-    outputFile = io.open(outputFilePath, 'w')
-end
-print('Opened output file '..outputFilePath)
+print('Opening output file '..outputPipeName)
+local outputPipe = util.openReadPipeWriter(outputPipeName)
+print('Opened output file '..outputPipeName)
 
 local function writeResponse(object)
-    outputFile:write(serpent.dump(object).."\n")
-    outputFile:flush()
+    outputPipe:write(serpent.dump(object).."\n")
+    outputPipe:flush()
 end
 
 local runner = Runner(Promise)

runner-wrapper.lua

@@ -7,21 +7,6 @@ local Promise = nil
 local util = nil
 local config = dofile(base.."/config.lua")
 local serpent = dofile(base.."/serpent.lua")
-local temps = {
-    os.getenv("TMPDIR"),
-    os.getenv("TEMP"),
-    os.getenv("TEMPDIR"),
-    os.getenv("TMP"),
-}
-
-local tempDir = "/tmp"
-for i=1,#temps,1 do
-    local temp = temps[i]
-    if temp ~= nil and temp ~= "" then
-        tempDir = temps[i]
-        break
-    end
-end
 
 local pipePrefix = "donk_runner_"..
     string.hex(math.floor(random.integer(0, 0xffffffff)))..
@@ -77,23 +62,18 @@ local function launchChildren(_M, count)
             input = nil,
         }
 
-        local outputFileName = outputPrefix..i
+        local outputPipeName = outputPrefix..i
         local inputPipeName = inputPrefix..i
-        local inputFileName = inputPrefix..i
-        if util.isWin then
-            outputFileName = '\\\\.\\pipe\\'..outputFileName
-            inputFileName = '\\\\.\\pipe\\'..inputPipeName
-        end
 
         local settingsDir = nil
         if util.isWin then
-            settingsDir = tempDir.."/donk_runner_settings_"..i
+            settingsDir = util.getTempDir().."/donk_runner_settings_"..i
             util.mkdir(settingsDir)
         end
 
         local envs = {
             RUNNER_INPUT_PIPE = inputPipeName,
-            RUNNER_OUTPUT_FILE = outputFileName,
+            RUNNER_OUTPUT_PIPE = outputPipeName,
             APPDATA = settingsDir,
         }
 
@@ -104,7 +84,7 @@ local function launchChildren(_M, count)
         local promise = util.promiseWrap(function()
             newOne.output:read("*l")
             while newOne.input == nil do
-                newOne.input = io.open(inputFileName, 'w')
+                newOne.input = util.openReadPipeWriter(inputPipeName)
             end
         end)
         table.insert(promises, promise)

util.lua

@@ -14,6 +14,26 @@ function _M.promiseWrap(next)
     return promise:next(next)
 end
 
+function _M.getTempDir()
+    local temps = {
+        os.getenv("TMPDIR"),
+        os.getenv("TEMP"),
+        os.getenv("TEMPDIR"),
+        os.getenv("TMP"),
+    }
+
+    local tempDir = "/tmp"
+    for i=1,#temps,1 do
+        local temp = temps[i]
+        if temp ~= nil and temp ~= "" then
+            tempDir = temps[i]
+            break
+        end
+    end
+
+    return tempDir
+end
+
 --- Echo a command, run it, and return the file handle
 --- @param cmd string The command to execute
 --- @param workdir string The working directory
@@ -60,10 +80,23 @@ function _M.openReadPipe(name)
         print(cmd)
         return io.popen(cmd, 'r')
     else
-        error('Not implemented')
+        return io.popen("socat 'UNIX-LISTEN:".._M.getTempDir().."/"..name.."' -", 'r')
     end
 end
 
+function _M.openReadPipeWriter(name)
+    local writer = nil
+    while writer == nil do
+        if _M.isWin then
+            writer = io.open('\\\\.\\pipe\\'..name, 'w')
+        else
+            writer = io.popen("socat 'UNIX-CONNECT:".._M.getTempDir().."/"..name.."' -", 'w')
+        end
+    end
+
+    return writer
+end
+
 --- Download a url
 --- @param url string URI of resource to download
 --- @param dest string File to save resource to