Clean up standard stream logic

Now we have enough portability stuff

src/libmain/progress-bar.cc

@@ -543,7 +543,7 @@ public:
         auto state(state_.lock());
         if (!state->active) return {};
         std::cerr << fmt("\r\e[K%s ", msg);
-        auto s = trim(readLine(STDIN_FILENO, true));
+        auto s = trim(readLine(getStandardInput(), true));
         if (s.size() != 1) return {};
         draw(*state);
         return s[0];

src/libutil/file-descriptor.hh

@@ -106,8 +106,25 @@ void drainFD(
 #endif
     );
 
+/**
+ * Get [Standard Input](https://en.wikipedia.org/wiki/Standard_streams#Standard_input_(stdin))
+ */
 [[gnu::always_inline]]
-inline Descriptor getStandardOut() {
+inline Descriptor getStandardInput()
+{
+#ifndef _WIN32
+    return STDIN_FILENO;
+#else
+    return GetStdHandle(STD_INPUT_HANDLE);
+#endif
+}
+
+/**
+ * Get [Standard Output](https://en.wikipedia.org/wiki/Standard_streams#Standard_output_(stdout))
+ */
+[[gnu::always_inline]]
+inline Descriptor getStandardOutput()
+{
 #ifndef _WIN32
     return STDOUT_FILENO;
 #else
@@ -115,6 +132,19 @@ inline Descriptor getStandardOut() {
 #endif
 }
 
+/**
+ * Get [Standard Error](https://en.wikipedia.org/wiki/Standard_streams#Standard_error_(stderr))
+ */
+[[gnu::always_inline]]
+inline Descriptor getStandardError()
+{
+#ifndef _WIN32
+    return STDERR_FILENO;
+#else
+    return GetStdHandle(STD_ERROR_HANDLE);
+#endif
+}
+
 /**
  * Automatic cleanup of resources.
  */

src/libutil/logging.cc

@@ -38,7 +38,7 @@ void Logger::warn(const std::string & msg)
 
 void Logger::writeToStdout(std::string_view s)
 {
-    Descriptor standard_out = getStandardOut();
+    Descriptor standard_out = getStandardOutput();
     writeFull(standard_out, s);
     writeFull(standard_out, "\n");
 }
@@ -118,11 +118,7 @@ void writeToStderr(std::string_view s)
 {
     try {
         writeFull(
-#ifdef _WIN32
-            GetStdHandle(STD_ERROR_HANDLE),
-#else
-            STDERR_FILENO,
-#endif
+            getStandardError(),
             s, false);
     } catch (SystemError & e) {
         /* Ignore failing writes to stderr.  We need to ignore write

src/nix-store/nix-store.cc

@@ -694,7 +694,7 @@ static void opDump(Strings opFlags, Strings opArgs)
     if (!opFlags.empty()) throw UsageError("unknown flag");
     if (opArgs.size() != 1) throw UsageError("only one argument allowed");
 
-    FdSink sink(getStandardOut());
+    FdSink sink(getStandardOutput());
     std::string path = *opArgs.begin();
     dumpPath(path, sink);
     sink.flush();
@@ -722,7 +722,7 @@ static void opExport(Strings opFlags, Strings opArgs)
     for (auto & i : opArgs)
         paths.insert(store->followLinksToStorePath(i));
 
-    FdSink sink(getStandardOut());
+    FdSink sink(getStandardOutput());
     store->exportPaths(paths, sink);
     sink.flush();
 }
@@ -835,7 +835,7 @@ static void opServe(Strings opFlags, Strings opArgs)
     if (!opArgs.empty()) throw UsageError("no arguments expected");
 
     FdSource in(STDIN_FILENO);
-    FdSink out(getStandardOut());
+    FdSink out(getStandardOutput());
 
     /* Exchange the greeting. */
     ServeProto::Version clientVersion =

src/nix/cat.cc

@@ -16,7 +16,7 @@ struct MixCat : virtual Args
             throw Error("path '%1%' is not a regular file", path);
         stopProgressBar();
 
-        writeFull(getStandardOut(), accessor->readFile(CanonPath(path)));
+        writeFull(getStandardOutput(), accessor->readFile(CanonPath(path)));
     }
 };
 

src/nix/dump-path.cc

@@ -20,7 +20,7 @@ struct CmdDumpPath : StorePathCommand
 
     void run(ref<Store> store, const StorePath & storePath) override
     {
-        FdSink sink(getStandardOut());
+        FdSink sink(getStandardOutput());
         store->narFromPath(storePath, sink);
         sink.flush();
     }
@@ -55,7 +55,7 @@ struct CmdDumpPath2 : Command
 
     void run() override
     {
-        FdSink sink(getStandardOut());
+        FdSink sink(getStandardOutput());
         dumpPath(path, sink);
         sink.flush();
     }

src/nix/eval.cc

@@ -115,7 +115,7 @@ struct CmdEval : MixJSON, InstallableValueCommand, MixReadOnlyOption
 
         else if (raw) {
             stopProgressBar();
-            writeFull(getStandardOut(), *state->coerceToString(noPos, *v, context, "while generating the eval command output"));
+            writeFull(getStandardOutput(), *state->coerceToString(noPos, *v, context, "while generating the eval command output"));
         }
 
         else if (json) {

src/nix/log.cc

@@ -57,7 +57,7 @@ struct CmdLog : InstallableCommand
             if (!log) continue;
             stopProgressBar();
             printInfo("got build log for '%s' from '%s'", installable->what(), logSub.getUri());
-            writeFull(getStandardOut(), *log);
+            writeFull(getStandardOutput(), *log);
             return;
         }
 

src/nix/sigs.cc

@@ -177,7 +177,7 @@ struct CmdKeyGenerateSecret : Command
             throw UsageError("required argument '--key-name' is missing");
 
         stopProgressBar();
-        writeFull(getStandardOut(), SecretKey::generate(*keyName).to_string());
+        writeFull(getStandardOutput(), SecretKey::generate(*keyName).to_string());
     }
 };
 
@@ -199,7 +199,7 @@ struct CmdKeyConvertSecretToPublic : Command
     {
         SecretKey secretKey(drainFD(STDIN_FILENO));
         stopProgressBar();
-        writeFull(getStandardOut(), secretKey.toPublicKey().to_string());
+        writeFull(getStandardOutput(), secretKey.toPublicKey().to_string());
     }
 };