79 lines
1.9 KiB
C++
79 lines
1.9 KiB
C++
/*============================================================================
|
|
KWSys - Kitware System Library
|
|
Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
|
|
|
|
Distributed under the OSI-approved BSD License (the "License");
|
|
see accompanying file Copyright.txt for details.
|
|
|
|
This software is distributed WITHOUT ANY WARRANTY; without even the
|
|
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
See the License for more information.
|
|
============================================================================*/
|
|
#include "kwsysPrivate.h"
|
|
#include KWSYS_HEADER(FStream.hxx)
|
|
|
|
// Work-around CMake dependency scanning limitation. This must
|
|
// duplicate the above list of headers.
|
|
#if 0
|
|
# include "FStream.hxx.in"
|
|
#endif
|
|
|
|
namespace KWSYS_NAMESPACE
|
|
{
|
|
namespace FStream
|
|
{
|
|
|
|
BOM ReadBOM(std::istream& in)
|
|
{
|
|
if(!in.good())
|
|
{
|
|
return BOM_None;
|
|
}
|
|
unsigned long orig = in.tellg();
|
|
unsigned char bom[4];
|
|
in.read(reinterpret_cast<char*>(bom), 2);
|
|
if(!in.good())
|
|
{
|
|
in.clear();
|
|
in.seekg(orig);
|
|
return BOM_None;
|
|
}
|
|
if(bom[0] == 0xEF && bom[1] == 0xBB)
|
|
{
|
|
in.read(reinterpret_cast<char*>(bom+2), 1);
|
|
if(in.good() && bom[2] == 0xBF)
|
|
{
|
|
return BOM_UTF8;
|
|
}
|
|
}
|
|
else if(bom[0] == 0xFE && bom[1] == 0xFF)
|
|
{
|
|
return BOM_UTF16BE;
|
|
}
|
|
else if(bom[0] == 0x00 && bom[1] == 0x00)
|
|
{
|
|
in.read(reinterpret_cast<char*>(bom+2), 2);
|
|
if(in.good() && bom[2] == 0xFE && bom[3] == 0xFF)
|
|
{
|
|
return BOM_UTF32BE;
|
|
}
|
|
}
|
|
else if(bom[0] == 0xFF && bom[1] == 0xFE)
|
|
{
|
|
unsigned long p = in.tellg();
|
|
in.read(reinterpret_cast<char*>(bom+2), 2);
|
|
if(in.good() && bom[2] == 0x00 && bom[3] == 0x00)
|
|
{
|
|
return BOM_UTF32LE;
|
|
}
|
|
in.seekg(p);
|
|
return BOM_UTF16LE;
|
|
}
|
|
in.clear();
|
|
in.seekg(orig);
|
|
return BOM_None;
|
|
}
|
|
|
|
} // FStream namespace
|
|
} //KWSYS_NAMESPACE
|