File now supports pipes ("cmd|", "|cmd") and "-" (stdin/stdout) for input and output;

stderr redirection now uses File class instead of auto_file_ptr, allowing e.g. stderr="|tee path.log";
new method File::Flush();
class File implementation now uses RuntimeError() and LogicError() instead of throw std::runtime_error() and logic_error();
moved RuntimeError() and class Plugin from basetypes.h to Basics.h;
new VS++ CRT emulation function _wpopen() (Linux only_

Common/ConfigFile.cpp

@@ -193,16 +193,16 @@ namespace Microsoft { namespace MSR { namespace CNTK {
     {
         File file(filePath, fileOptionsRead);
 
-        // initialize with file name
-        std::string path = msra::strfun::utf8(filePath);
-        auto location = path.find_last_of("/\\");
+        // initialize configName with file name
+        std::string configName = msra::strfun::utf8(filePath);
+        auto location = configName.find_last_of("/\\");
         if (location != npos)
-            path = path.substr(location+1);
-        m_configName = move(path);
+            configName = configName.substr(location+1);
+        m_configName = move(configName);
 
         // read the entire file into a string
-        // CONSIDER: should the File API support this, instead of line by line?
-        size_t fileLength = file.Size();
+        // CONSIDER: should the File API support this, instead of us having to call it line by line?
+        size_t fileLength = file.CanSeek() ? file.Size() : 0;
         string str;
         string configFile;
         configFile.reserve(fileLength);

Common/File.cpp

@@ -7,6 +7,7 @@
 #ifndef _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_WARNINGS // "secure" CRT not available on all platforms  --add this at the top of all CPP files that give "function or variable may be unsafe" warnings
 #endif
+#define _CRT_NONSTDC_NO_DEPRECATE   // make VS accept POSIX functions without _
 
 #include "Basics.h"
 #define FORMAT_SPECIALIZE // to get the specialized version of the format routines
@@ -22,7 +23,7 @@
 #include <unistd.h>
 #endif
 
-namespace Microsoft{ namespace MSR { namespace CNTK {
+namespace Microsoft { namespace MSR { namespace CNTK {
 
 // File creation
 // filename - the path
@@ -43,16 +44,32 @@ File::File(const wchar_t* filename, int fileOptions)
     Init(filename, fileOptions);
 }
 
+// all constructors call this
 void File::Init(const wchar_t* filename, int fileOptions)
 {
-    msra::files::make_intermediate_dirs(filename);
+    m_filename = filename;
+    m_options = fileOptions;
+    if (m_filename.empty())
+        RuntimeError("File: filename is empty");
+    const auto outputPipe = (m_filename.front() == '|');
+    const auto inputPipe  = (m_filename.back()  == '|');
     // translate the options string into a string for fopen()
-    wstring options = fileOptions&fileOptionsRead?L"r":L"";
-    if (fileOptions&fileOptionsWrite)
+    const auto reading = !!(fileOptions & fileOptionsRead);
+    const auto writing = !!(fileOptions & fileOptionsWrite);
+    if (!reading && !writing)
+        RuntimeError("File: either fileOptionsRead or fileOptionsWrite must be specified");
+    // convert fileOptions to fopen()'s mode string
+    wstring options = reading ? L"r" : L"";
+    if (writing)
     {
         // if we already are reading the file, change to read/write
         options.clear();
-        options.append(L"w+");
+        options.append(L"w");
+        if (!outputPipe && m_filename != L"-")
+        {
+            options.append(L"+");
+            msra::files::make_intermediate_dirs(m_filename.c_str());    // writing to regular file -> also create the intermediate directories as a convenience
+        }
     }
     if (fileOptions&fileOptionsBinary)
     {
@@ -71,13 +88,40 @@ void File::Init(const wchar_t* filename, int fileOptions)
     // add sequential flag to allocate big read buffer
     if (fileOptions & fileOptionsSequential)
         options += L"S";
-
-    attempt([=](){m_file = fopenOrDie(filename, options.c_str());});
-    m_options = fileOptions;
-    m_size = filesize(m_file);
+    // now open the file
+    // Special path syntax understood here:
+    //  - "-" refers to stdin or stdout
+    //  - "|cmd" writes to a pipe
+    //  - "cmd|" reads from a pipe
+    m_pcloseNeeded = false;
+    m_seekable = false;
+    if (m_filename == L"-")                                 // stdin/stdout
+    {
+        if (writing && reading)
+            RuntimeError("File: path '-' fileOptionsRead and fileOptionsWrite at once");
+        m_file = writing ? stdout : stdin;
+    }
+    else if (outputPipe || inputPipe)                       // pipe syntax
+    {
+        if (inputPipe && outputPipe)
+            RuntimeError("File: pipes cannot specify fileOptionsRead and fileOptionsWrite at once");
+        if (inputPipe != reading)
+            RuntimeError("File: pipes must use consistent fileOptionsRead/fileOptionsWrite");
+        const auto command = inputPipe ? m_filename.substr(0, m_filename.size() - 1) : m_filename.substr(1);
+        m_file = _wpopen(command.c_str(), options.c_str());
+        if (!m_file)
+            RuntimeError("File: error exexuting pipe command '%S': %s", command.c_str(), strerror(errno));
+        m_pcloseNeeded = true;
+    }
+    else attempt([=]()                                      // regular file: use a retry loop
+    {
+        m_file = fopenOrDie(filename, options.c_str());
+        m_seekable = true;
+    });
 }
 
-void File::goToDelimiter(int delim)
+// skip to given delimiter character
+void File::SkipToDelimiter(int delim)
 {
     int ch=0;
 
@@ -85,7 +129,7 @@ void File::goToDelimiter(int delim)
         ch=fgetc(m_file);
         if (feof(m_file)) {
             printf("Unexpected end of file\n");
-            throw std::logic_error("Unexpected end of file\n");
+            LogicError("Unexpected end of file\n");
         }
     }
 }
@@ -97,9 +141,18 @@ bool File::IsTextBased()
 
 // File Destructor
 // closes the file
+// Note: this does not check for errors. Use Flush() before closing a file you are writing.
 File::~File(void)
 {
-    attempt([=] {fcloseOrDie(m_file);});
+    if (m_pcloseNeeded)
+        _pclose(m_file);
+    else if (m_file != stdin && m_file != stdout && m_file != stderr)
+        fclose(m_file); // (since destructors may not throw, we ignore the return code here)
+}
+
+void File::Flush()
+{
+    fflushOrDie(m_file);
 }
 
 // GetLine - get a line from the file
@@ -208,7 +261,8 @@ File& File::PutMarker(FileMarker marker, const std::wstring& section)
 // val - value to read from the file
 File& File::operator>>(std::wstring& val)
 {
-    attempt([&]{
+    attempt([&]
+    {
         if (IsTextBased())
             val = fgetwtoken(m_file);
         else
@@ -221,7 +275,8 @@ File& File::operator>>(std::wstring& val)
 // val - value to read from the file
 File& File::operator>>(std::string& val)
 {
-    attempt([&]{
+    attempt([&]
+    {
         if (IsTextBased())
             val = fgettoken(m_file);
         else
@@ -341,7 +396,8 @@ void File::WriteString(const wchar_t* str, int size)
 // size - size of the string string buffer
 void File::ReadString(wchar_t* str, int size)
 {
-    attempt([&]{
+    attempt([&]
+    {
         if (IsTextBased())
             fgettoken(m_file, str, size);
         else
@@ -390,6 +446,8 @@ bool File::IsUnicodeBOM(bool skip)
 // WARNING: calling this will reset the EOF marker, so do so with care
 size_t File::Size()
 {
+    if (!CanSeek())
+        RuntimeError("File: attempted to get Size() on non-seekable stream");
     return filesize(m_file);
 }
 
@@ -469,7 +527,7 @@ File& File::operator>>(FileMarker marker)
         break;
     case fileMarkerEndFile: // end of file marker, should we throw if it's not the end of the file?
         if (!IsEOF())
-            throw std::runtime_error("fileMarkerEndFile not found");
+            RuntimeError("fileMarkerEndFile not found");
         break;
     case fileMarkerBeginList: // Beginning of list marker
         // no marker written unless an list with a count header
@@ -483,7 +541,7 @@ File& File::operator>>(FileMarker marker)
         {
             int found = EndOfLineOrEOF(true);
             if (found != (int)true) // EOF can also be returned
-                throw std::runtime_error("Newline not found");
+                RuntimeError("Newline not found");
         }
         break;
     case fileMarkerBeginSection: // beginning of section
@@ -556,7 +614,7 @@ File& File::GetMarker(FileMarker marker, const std::string& section)
     string str;
     *this >> str;
     if (str != section)
-        throw std::runtime_error(std::string("section name mismatch ") + str + " != " + section);
+        RuntimeError(std::string("section name mismatch ") + str + " != " + section);
     return *this;
 }
 
@@ -569,7 +627,7 @@ File& File::GetMarker(FileMarker marker, const std::wstring& section)
     wstring str;
     *this >> str;
     if (str != section)
-        throw std::runtime_error(std::string("section name mismatch ") + msra::strfun::utf8(str) + " != " + msra::strfun::utf8(section));
+        RuntimeError(std::string("section name mismatch ") + msra::strfun::utf8(str) + " != " + msra::strfun::utf8(section));
     return *this;
 }
 
@@ -620,6 +678,8 @@ bool File::TryGetMarker(FileMarker marker, const std::string& section)
 // GetPosition - Get position in a file
 uint64_t File::GetPosition()
 {
+    if (!CanSeek())
+        RuntimeError("File: attempted to GetPosition() on non-seekable stream");
     return fgetpos(m_file);
 }
 
@@ -627,7 +687,9 @@ uint64_t File::GetPosition()
 // pos - position in the file
 void File::SetPosition(uint64_t pos)
 {
-    fsetpos (m_file, pos);
+    if (!CanSeek())
+        RuntimeError("File: attempted to SetPosition() on non-seekable stream");
+    fsetpos(m_file, pos);
 }
 
 }}}

Common/Include/Basics.h

@@ -25,7 +25,95 @@ namespace Microsoft { namespace MSR { namespace CNTK {
         bool operator()(const std::wstring& left, const std::wstring& right) { return _wcsicmp(left.c_str(), right.c_str()) < 0; }
     };
 
-}}}
+    // RuntimeError - throw a std::runtime_error with a formatted error string
+#ifdef _MSC_VER
+    __declspec(noreturn)
+#endif
+    static inline void RuntimeError(const char * format, ...)
+    {
+        va_list args;
+        char buffer[1024];
+
+        va_start(args, format);
+        vsprintf(buffer, format, args);
+        throw std::runtime_error(buffer);
+    };
+    static inline void RuntimeError(const string & message) { RuntimeError("%s", message.c_str()); }
+
+    // LogicError - throw a std::logic_error with a formatted error string
+#ifdef _MSC_VER
+    __declspec(noreturn)
+#endif
+    static inline void LogicError(const char * format, ...)
+    {
+        va_list args;
+        char buffer[1024];
+
+        va_start(args, format);
+        vsprintf(buffer, format, args);
+        throw std::logic_error(buffer);
+    };
+    static inline void LogicError(const string & message) { RuntimeError("%s", message.c_str()); }
+
+    // ----------------------------------------------------------------------------
+    // dynamic loading of modules  --TODO: not Basics, should move to its own header
+    // ----------------------------------------------------------------------------
+
+#ifdef _WIN32
+    class Plugin
+    {
+        HMODULE m_hModule;      // module handle for the writer DLL
+        std::wstring m_dllName; // name of the writer DLL
+    public:
+        Plugin() { m_hModule = NULL; }
+        template<class STRING>  // accepts char (UTF-8) and wide string 
+        FARPROC Load(const STRING & plugin, const std::string & proc)
+        {
+            m_dllName = msra::strfun::utf16(plugin);
+            m_dllName += L".dll";
+            m_hModule = LoadLibrary(m_dllName.c_str());
+            if (m_hModule == NULL)
+                Microsoft::MSR::CNTK::RuntimeError("Plugin not found: %s", msra::strfun::utf8(m_dllName).c_str());
+
+            // create a variable of each type just to call the proper templated version
+            return GetProcAddress(m_hModule, proc.c_str());
+        }
+        ~Plugin(){}
+        // removed because this causes the exception messages to be lost  (exception vftables are unloaded when DLL is unloaded) 
+        // ~Plugin() { if (m_hModule) FreeLibrary(m_hModule); }
+    };
+#else
+    class Plugin
+    {
+    private:
+        void *handle;
+    public:
+        Plugin()
+        {
+            handle = NULL;
+        }
+
+        template<class STRING>  // accepts char (UTF-8) and wide string 
+        void * Load(const STRING & plugin, const std::string & proc)
+        {
+            string soName = msra::strfun::utf8(plugin);
+            soName = soName + ".so";
+            void *handle = dlopen(soName.c_str(), RTLD_LAZY);
+            if (handle == NULL)
+                RuntimeError("Plugin not found: %s", soName.c_str());
+            return dlsym(handle, proc.c_str());
+        }
+
+        ~Plugin() {
+            if (handle != NULL)
+                dlclose(handle);
+        }
+    };
+#endif
+
+}
+}
+}
 
 // ===========================================================================
 // emulation of some MSVC proprietary CRT
@@ -33,6 +121,7 @@ namespace Microsoft { namespace MSR { namespace CNTK {
 
 #ifndef _MSC_VER
 static inline int _wsystem(const wchar_t *command) { return system(msra::strfun::utf8(command).c_str()); }
+static inline int _wpopen(const wchar_t * command, const wchar_t mode) { return open(msra::strfun::utf8(command).c_str(), msra::strfun::utf8(mode).c_str()); }
 #endif
 
 #endif // _BASICS_H_

Common/Include/File.h

@@ -18,6 +18,8 @@
 
 namespace Microsoft{ namespace MSR { namespace CNTK {
 
+using namespace std;
+
 // file options, Type of textfile to use
 enum FileOptions
 {
@@ -86,9 +88,11 @@ template<typename FUNCTION> static void attempt (const FUNCTION & body)
 class File
 {
 private:
-    FILE* m_file;
-    size_t m_size;
-    int m_options; // FileOptions ored togther
+    std::wstring m_filename;
+    FILE* m_file;           // file handle
+    bool m_pcloseNeeded;    // was opened with popen(), use pclose() when destructing
+    bool m_seekable;        // this stream is seekable
+    int m_options;          // FileOptions ored togther
     void Init(const wchar_t* filename, int fileOptions);
 
 public:
@@ -97,13 +101,16 @@ public:
     File(const wchar_t* filename, int fileOptions);
     ~File(void);
 
+    void Flush();
+
+    bool CanSeek() const { return m_seekable; }
+    size_t Size();
     uint64_t GetPosition();
     void SetPosition(uint64_t pos);
-    void goToDelimiter(int delim);
+    void SkipToDelimiter(int delim);
 
     bool IsTextBased();
 
-    size_t Size();
     bool IsUnicodeBOM(bool skip=false);
     bool IsEOF();
     bool IsWhiteSpace(bool skip=false);
@@ -230,6 +237,8 @@ public:
         }
         return *this;
     }
+
+    operator FILE*() const { return m_file; }
 };
 
 }}}

Common/Include/basetypes.h

@@ -1019,90 +1019,6 @@ using namespace msra::basetypes;    // for compatibility
 
 #pragma warning (pop)
 
-// RuntimeError - throw a std::runtime_error with a formatted error string
-#ifdef _MSC_VER
-__declspec(noreturn)
-#endif
-static inline void RuntimeError(const char * format, ...)
-{
-    va_list args;
-    char buffer[1024];
-
-    va_start (args, format);
-    vsprintf (buffer, format, args);
-    throw std::runtime_error(buffer);
-};
-
-// LogicError - throw a std::logic_error with a formatted error string
-#ifdef _MSC_VER
-__declspec(noreturn)
-#endif
-static inline void LogicError(const char * format, ...)
-{
-    va_list args;
-    char buffer[1024];
-
-    va_start(args, format);
-    vsprintf(buffer, format, args);
-    throw std::logic_error(buffer);
-};
-
-// ----------------------------------------------------------------------------
-// dynamic loading of modules
-// ----------------------------------------------------------------------------
-
-#ifdef _WIN32
-class Plugin
-{
-    HMODULE m_hModule;      // module handle for the writer DLL
-    std::wstring m_dllName; // name of the writer DLL
-public:
-    Plugin() { m_hModule = NULL; }
-    template<class STRING>  // accepts char (UTF-8) and wide string 
-    FARPROC Load(const STRING & plugin, const std::string & proc)
-    {
-        m_dllName = msra::strfun::utf16(plugin);
-        m_dllName += L".dll";
-        m_hModule = LoadLibrary(m_dllName.c_str());
-        if (m_hModule == NULL)
-            RuntimeError("Plugin not found: %s", msra::strfun::utf8(m_dllName).c_str());
-
-        // create a variable of each type just to call the proper templated version
-        return GetProcAddress(m_hModule, proc.c_str());
-    }
-    ~Plugin(){} 
-    // removed because this causes the exception messages to be lost  (exception vftables are unloaded when DLL is unloaded) 
-    // ~Plugin() { if (m_hModule) FreeLibrary(m_hModule); }
-};
-#else
-class Plugin
-{
-private:
-	void *handle;
-public:
-	Plugin() 
-	{ 
-		handle = NULL; 
-	}
-
-    template<class STRING>  // accepts char (UTF-8) and wide string 
-    void * Load(const STRING & plugin, const std::string & proc)
-    {
-		string soName = msra::strfun::utf8(plugin);
-		soName = soName + ".so";
-		void *handle = dlopen(soName.c_str(), RTLD_LAZY);
-		if (handle == NULL)
-            RuntimeError("Plugin not found: %s", soName.c_str());
-		return dlsym(handle, proc.c_str());
-    }
-
-	~Plugin() {
-		if (handle != NULL)
-			dlclose(handle);
-	}
-};
-#endif
-
 #if 0   // construction site
 // ----------------------------------------------------------------------------
 // class RegisterModule

Common/fileutil.cpp

@@ -54,6 +54,7 @@
 #include <errno.h>
 
 using namespace std;
+using namespace Microsoft::MSR::CNTK;
 
 // ----------------------------------------------------------------------------
 // some mappings for non-Windows builds

DataReader/LMSequenceReader/SequenceParser.cpp

@@ -7,12 +7,14 @@
 //
 
 #include "stdafx.h"
-#include "Basics.h"
-#include "SequenceParser.h"
 #include <stdexcept>
 #include <stdint.h>
+#include "Basics.h"
+#include "SequenceParser.h"
 #include "fileutil.h"
 
+using namespace Microsoft::MSR::CNTK;
+
 // SetState for a particular value
 template <typename NumType, typename LabelType>
 void SequenceParser<NumType, LabelType>::SetState(int value, ParseState m_current_state, ParseState next_state)

DataReader/LMSequenceReader/SequenceParser.h

@@ -12,6 +12,7 @@
 #include <fstream>
 #include <map>
 #include <stdint.h>
+#include "Basics.h"
 #include "fileutil.h"
 
 using namespace std;
@@ -232,10 +233,10 @@ public:
 
         errno_t err = _wfopen_s( &m_pFile, fileName, L"rb" );
         if (err)
-            RuntimeError("SequenceParser::ParseInit - error opening file"); 
+            Microsoft::MSR::CNTK::RuntimeError("SequenceParser::ParseInit - error opening file");
         int rc = _fseeki64(m_pFile, 0, SEEK_END);
         if (rc)
-            RuntimeError("SequenceParser::ParseInit - error seeking in file");
+            Microsoft::MSR::CNTK::RuntimeError("SequenceParser::ParseInit - error seeking in file");
 
         m_fileSize = GetFilePosition();
         m_fileBuffer = new BYTE[m_bufferSize];
@@ -543,7 +544,7 @@ public:
         if (mFile) fclose(mFile);
 
         if (_wfopen_s(&mFile, fileName, L"rt") != 0)
-            RuntimeError("cannot open file %s", fileName);
+            Microsoft::MSR::CNTK::RuntimeError("cannot open file %s", fileName);
     }
 
     void ParseReset()

MachineLearning/CNTK/CNTK.cpp

@@ -68,11 +68,11 @@ struct compare_second
 void RedirectStdErr(wstring logpath)
 {
     fprintf(stderr, "Redirecting stderr to file %S\n", logpath.c_str());
-    msra::files::make_intermediate_dirs(logpath);
-    auto_file_ptr f(logpath.c_str(), "wb");
-    if (dup2(fileno(f), 2) == -1)
+    auto f = make_shared<File>(logpath.c_str(), fileOptionsWrite | fileOptionsText);
+    if (dup2(fileno(*f), 2) == -1)
         RuntimeError("unexpected failure to redirect stderr to log file");
     setvbuf(stderr, NULL, _IONBF, 16384);   // unbuffer it
+    static auto fKept = f;                  // keep it around (until it gets changed)
 }
 
 std::string WCharToString(const wchar_t* wst)
@@ -1017,7 +1017,6 @@ void PrintUsageInfo()
 
 int wmain(int argc, wchar_t* argv[])
 {
-
     try
     {
 #ifdef MPI_SUPPORT