From 1b4e9434e4a3ac82285486d730f32a1697139f5f Mon Sep 17 00:00:00 2001
From: Ryan Houdek <Sonicadvance1@gmail.com>
Date: Tue, 26 Nov 2019 09:03:52 -0800
Subject: [PATCH] Add accurate std output option

This gives us accurate stdout and stderr output.
Useful for terminal applications that take advantage of ncurses or
similar
---
 Source/Interface/Config/Config.cpp      |  6 +++++
 Source/Interface/Context/Context.h      |  1 +
 Source/Interface/HLE/FileManagement.cpp | 31 ++++++++++++++++---------
 include/FEXCore/Config/Config.h         |  1 +
 4 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/Source/Interface/Config/Config.cpp b/Source/Interface/Config/Config.cpp
index 3bf59ed32..df02d8f1a 100644
--- a/Source/Interface/Config/Config.cpp
+++ b/Source/Interface/Config/Config.cpp
@@ -24,6 +24,9 @@ namespace FEXCore::Config {
     case FEXCore::Config::CONFIG_GDBSERVER:
       Config != 0 ? CTX->StartGdbServer() : CTX->StopGdbServer();
     break;
+    case FEXCore::Config::CONFIG_ACCURATESTDOUT:
+      CTX->Config.AccurateSTDOut = Config != 0;
+    break;
     default: LogMan::Msg::A("Unknown configuration option");
     }
   }
@@ -47,6 +50,9 @@ namespace FEXCore::Config {
     case FEXCore::Config::CONFIG_GDBSERVER:
       return CTX->GetGdbServerStatus();
     break;
+    case FEXCore::Config::CONFIG_ACCURATESTDOUT:
+      return CTX->Config.AccurateSTDOut;
+    break;
     default: LogMan::Msg::A("Unknown configuration option");
     }
 
diff --git a/Source/Interface/Context/Context.h b/Source/Interface/Context/Context.h
index 7dda4f494..b3872f1b7 100644
--- a/Source/Interface/Context/Context.h
+++ b/Source/Interface/Context/Context.h
@@ -41,6 +41,7 @@ namespace FEXCore::Context {
     struct {
       bool Multiblock {false};
       bool BreakOnFrontendFailure {true};
+      bool AccurateSTDOut {false};
       int64_t MaxInstPerBlock {-1LL};
       uint64_t VirtualMemSize {1ULL << 36};
       FEXCore::Config::ConfigCore Core {FEXCore::Config::CONFIG_INTERPRETER};
diff --git a/Source/Interface/HLE/FileManagement.cpp b/Source/Interface/HLE/FileManagement.cpp
index d2cc19bb8..0327b7823 100644
--- a/Source/Interface/HLE/FileManagement.cpp
+++ b/Source/Interface/HLE/FileManagement.cpp
@@ -36,20 +36,29 @@ public:
 
     OutputString += '\0';
 
-   if (FDOffset == STDOUT_FILENO)
-     LogMan::Msg::OUT("[%ld] %s", FinalSize, OutputString.c_str());
-   else if (FDOffset == STDERR_FILENO)
-     LogMan::Msg::ERR("[%ld] %s", FinalSize, OutputString.c_str());
-
-    return FinalSize;
+    if (CTX->Config.AccurateSTDOut) {
+      return ::writev(fd, (const struct iovec*)iov, iovcnt);
+    }
+    else {
+      if (FDOffset == STDOUT_FILENO)
+        LogMan::Msg::OUT("[%ld] %s", FinalSize, OutputString.c_str());
+      else if (FDOffset == STDERR_FILENO)
+        LogMan::Msg::ERR("[%ld] %s", FinalSize, OutputString.c_str());
+      return FinalSize;
+    }
   }
 
   uint64_t write(int fd, void *buf, size_t count) override {
-   if (FDOffset == STDOUT_FILENO)
-     LogMan::Msg::OUT("%s", reinterpret_cast<char*>(buf));
-   else if (FDOffset == STDERR_FILENO)
-     LogMan::Msg::ERR("%s", reinterpret_cast<char*>(buf));
-    return count;
+    if (CTX->Config.AccurateSTDOut) {
+      return ::write(fd, buf, count);
+    }
+    else {
+      if (FDOffset == STDOUT_FILENO)
+        LogMan::Msg::OUT("%s", reinterpret_cast<char*>(buf));
+      else if (FDOffset == STDERR_FILENO)
+        LogMan::Msg::ERR("%s", reinterpret_cast<char*>(buf));
+      return count;
+    }
   }
 };
 
diff --git a/include/FEXCore/Config/Config.h b/include/FEXCore/Config/Config.h
index 5c87fba33..3910fbca7 100644
--- a/include/FEXCore/Config/Config.h
+++ b/include/FEXCore/Config/Config.h
@@ -11,6 +11,7 @@ namespace FEXCore::Config {
     CONFIG_VIRTUALMEMSIZE,
     CONFIG_SINGLESTEP,
     CONFIG_GDBSERVER,
+    CONFIG_ACCURATESTDOUT,
   };
 
   enum ConfigCore {