diff --git a/configure b/configure
index 676edfb..625c4a7 100755
--- a/configure
+++ b/configure
@@ -3251,8 +3251,8 @@ ac_config_headers="$ac_config_headers config.h"
 rm -f src/tripwire/syslog.h 2> /dev/null
 chmod 755 install-sh 2> /dev/null
 
-CFLAGS=${CFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor"}
-CXXFLAGS=${CXXFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor"}
+CFLAGS=${CFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor -D_LARGEFILE_SOURCE"}
+CXXFLAGS=${CXXFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor -D_LARGEFILE_SOURCE"}
 
 # Check whether --enable-static was given.
 if test "${enable_static+set}" = set; then :
diff --git a/configure.in b/configure.in
index da57683..e3cb322 100644
--- a/configure.in
+++ b/configure.in
@@ -17,8 +17,8 @@ chmod 755 install-sh 2> /dev/null
 dnl ###############
 dnl Setup defaults
 dnl ###############
-CFLAGS=${CFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor"}
-CXXFLAGS=${CXXFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor"}
+CFLAGS=${CFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor -D_LARGEFILE_SOURCE"}
+CXXFLAGS=${CXXFLAGS:-"-O -pipe -Wall -Wno-non-virtual-dtor -D_LARGEFILE_SOURCE"}
 
 dnl #####################
 dnl Configuration options
diff --git a/src/core/archive.cpp b/src/core/archive.cpp
old mode 100644
new mode 100755
index fdcbc3e..08c7813
--- a/src/core/archive.cpp
+++ b/src/core/archive.cpp
@@ -678,6 +678,7 @@ void cFileArchive::OpenRead(const TCHAR* filename, uint32 openFlags)
         uint32 flags = cFile::OPEN_READ;
         flags |= ( ( openFlags & FA_OPEN_TRUNCATE ) ? cFile::OPEN_TRUNCATE : 0 );
         flags |= ( ( openFlags & FA_OPEN_TEXT     ) ? cFile::OPEN_TEXT     : 0 );
+        flags |= ( ( openFlags & FA_NONBLOCKING ) ?   cFile::OPEN_NONBLOCKING :0 ); 
 
 		mCurrentFilename = filename;
 		mCurrentFile.Open( filename, flags );
@@ -703,6 +704,7 @@ void cFileArchive::OpenReadWrite(const TCHAR* filename, uint32 openFlags)
         uint32 flags = cFile::OPEN_WRITE;
         flags |= ( ( openFlags & FA_OPEN_TRUNCATE ) ? cFile::OPEN_TRUNCATE : 0 );
         flags |= ( ( openFlags & FA_OPEN_TEXT     ) ? cFile::OPEN_TEXT     : 0 );
+        flags |= ( ( openFlags & FA_NONBLOCKING ) ?   cFile::OPEN_NONBLOCKING :0 ); 
 
 		mCurrentFilename = filename;
 		mCurrentFile.Open( filename, flags );
diff --git a/src/core/archive.h b/src/core/archive.h
old mode 100644
new mode 100755
index 810f7ed..4819bc5
--- a/src/core/archive.h
+++ b/src/core/archive.h
@@ -259,7 +259,8 @@ public:
     enum OpenFlags
     {
         FA_OPEN_TEXT        = 0x1,
-        FA_OPEN_TRUNCATE    = 0x2
+        FA_OPEN_TRUNCATE    = 0x2,
+        FA_NONBLOCKING      = 0x4   
     };
 
     // TODO: Open should throw
diff --git a/src/core/file.h b/src/core/file.h
old mode 100644
new mode 100755
index 3289660..77c53b2
--- a/src/core/file.h
+++ b/src/core/file.h
@@ -81,22 +81,22 @@ public:
 
 	enum SeekFrom 
 	{
-		SEEK_BEGIN = 0,
-		SEEK_CURRENT,
-		SEEK_EOF
+            SEEK_BEGIN = 0,
+            SEEK_CURRENT,
+            SEEK_EOF
 	};
 
 	enum OpenFlags
 	{
-		// note that reading from the file is implicit
-		//
-		OPEN_READ			= 0x00000001,	// not needed, but makes calls nice...
-		OPEN_WRITE			= 0x00000002,	// we will be writing to the file
-		OPEN_LOCKED_TEMP	= 0x00000004,	// the file should not be readable by other processes and should be removed when closed
-		OPEN_TRUNCATE		= 0x00000008,	// opens an empty file. creates it if it doesn't exist. Doesn't make much sense without OF_WRITE
-		OPEN_CREATE			= 0x00000010,	// create the file if it doesn't exist; this is implicit if OF_TRUNCATE is set
-		OPEN_TEXT			= 0x00000020,
-		OPEN_EXCLUSIVE			= 0x00000040	// Use O_CREAT | O_EXCL
+            // note that reading from the file is implicit	
+            OPEN_READ          = 0x00000001,	// not needed, but makes calls nice...
+            OPEN_WRITE         = 0x00000002,	// we will be writing to the file
+            OPEN_LOCKED_TEMP   = 0x00000004,	// the file should not be readable by other processes and should be removed when closed
+            OPEN_TRUNCATE      = 0x00000008,	// opens an empty file. creates it if it doesn't exist. Doesn't make much sense without OF_WRITE
+            OPEN_CREATE         = 0x00000010,	// create the file if it doesn't exist; this is implicit if OF_TRUNCATE is set
+            OPEN_TEXT           = 0x00000020,
+            OPEN_EXCLUSIVE      = 0x00000040,	// Use O_CREAT | O_EXCL
+            OPEN_NONBLOCKING    = 0x00000080,    // Use non-blocking i/o [Unix]
 	};
 
 	//Ctor, Dtor, CpyCtor, Operator=:
diff --git a/src/core/file_unix.cpp b/src/core/file_unix.cpp
old mode 100644
new mode 100755
index 94b92db..ab031f3
--- a/src/core/file_unix.cpp
+++ b/src/core/file_unix.cpp
@@ -165,10 +165,13 @@ void cFile::Open( const TSTRING& sFileNameC, uint32 flags )
 		openmode = (mode_t) 0600; // Make sure only root can read the file
 	}
 
-	if ( flags & OPEN_CREATE )
-		perm |= O_CREAT;
-
+        if ( flags & OPEN_CREATE )
+            perm |= O_CREAT;
 
+#ifdef O_NONBLOCK
+        if( flags & OPEN_NONBLOCKING )
+            perm |= O_NONBLOCK;
+#endif
 	//
 	// actually open the file
 	//
diff --git a/src/fs/fspropcalc.cpp b/src/fs/fspropcalc.cpp
old mode 100644
new mode 100755
index 72dac00..8400a6c
--- a/src/fs/fspropcalc.cpp
+++ b/src/fs/fspropcalc.cpp
@@ -295,7 +295,7 @@ void cFSPropCalc::VisitFSObject(cFSObject& obj)
 				pTheArch = &arch;
                 try 
                 {
-				    arch.OpenRead(strName.c_str());
+				    arch.OpenRead(strName.c_str(), cFileArchive::FA_NONBLOCKING);
                 }
                 catch (eArchive&)
 				{