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