From Forum Nokia Wiki

ID	...	Creation date	July 2, 2009
Platform	S60 3rd Edition, FP1, FP2 S60 5th Edition	Tested on devices	Nokia N97
Category	Symbian	Subcategory

Keywords (APIs, classes, methods, functions): UTF-8,ConvertToUnicodeFromUtf8

This code snippet shows how to read simple plain text settings file stored in the UTF-8 format. Settings are stored as key value pairs in the text file.

For example:
Name: Föx Mǔlder

Remember to add LIBRARY charconv.lib to your project's .mmp file.

Header file

#ifndef CUTF8FILEPARSER_H
#define CUTF8FILEPARSER_H
 
#include <e32std.h>
#include <e32base.h>
 
class CUTF8FileParser : public CBase
	{
public:	
	//Destructor
	~CUTF8FileParser();
	//Two-phased constructor
	static CUTF8FileParser* NewL();
	static CUTF8FileParser* NewLC();
 
	//aSettingsFileName UTF-8 encoded file to be parsed  
	int ParseSettingsFileL(const TDesC& aSettingsFileName);
 
private:
	//Splits the line into a key and value
	void ParseLine(const TDesC& aLine, TPtrC16& aKey, TPtrC16& aValue);
 
	//Constructor for performing 1st stage construction	 */
	CUTF8FileParser();
	void ConstructL();
 
private:
	RFs iFs;	
	};
#endif // CUTF8FILEPARSER_H

source file

#include <f32file.h>
#include <utf.h>   
 
#include "UTF8FileParser.h"
 
//setting keys 
_LIT(KVersion,"Version:");
_LIT(KText,"Text:");
 
_LIT8(KBOM, "\xEF\xBB\xBF"); //notepad uses bom (byte order mark) when saving as UTF-8
_LIT8(KCRLF,"\x0D\x0A"); //windows newline
_LIT8(KLF,"\x0A"); //linux newline
 
CUTF8FileParser::CUTF8FileParser()	{	}
 
CUTF8FileParser::~CUTF8FileParser()
  {
 iFs.Close();
  }
 
CUTF8FileParser* CUTF8FileParser::NewLC()
  {
  CUTF8FileParser* self = new (ELeave) CUTF8FileParser();
  CleanupStack::PushL(self);
  self->ConstructL();
  return self;
  }
 
CUTF8FileParser* CUTF8FileParser::NewL()
  {
  CUTF8FileParser* self = CUTF8FileParser::NewLC();
  CleanupStack::Pop(); // self;
  return self;
  }
 
void CUTF8FileParser::ConstructL()
  {
  User::LeaveIfError(iFs.Connect());
  }
 
int CUTF8FileParser::ParseSettingsFileL(const TDesC& aSettingsFileName)
  { 
  TInt size=0;
 
  TInt posNewLineDelim = KErrNotFound;
 
  RDebug::Print(_L("#### Parsing file %S"), &aSettingsFileName);
 
  RFile file;
  TInt err;
  err = file.Open(iFs,aSettingsFileName, EFileRead);
 
  if(err != KErrNone)
    	{
    	RDebug::Print(_L("#### Error opening descriptor file %d"), err);
    	User::LeaveIfError(err);
    	}
 
  CleanupClosePushL(file);
 
  file.Size(size);
  HBufC8 *fileContents = HBufC8::NewLC(size);
 
  TPtr8 fileContentsPtr = fileContents->Des();
  file.Read(fileContentsPtr);
 
  //check newline used in the file http://en.wikipedia.org/wiki/Newline   
  //start with windows
  TPtrC8 newlineDelimeter;
  newlineDelimeter.Set(KCRLF);
 
  if(fileContentsPtr.Find(newlineDelimeter) == KErrNotFound) //unix file or no newlines
    {
    RDebug::Print(_L("#### Newline delimeter set to unix"));
    newlineDelimeter.Set(KLF);
    }
 
  //skip BOM if present
  if(fileContentsPtr.Find(KBOM) != KErrNotFound)
    {
    fileContentsPtr= fileContentsPtr.Right(fileContentsPtr.Length()-KBOM().Length());
    RDebug::Print(_L("#### bom stripped"));
    RDebug::Print(_L("#### remaining length %d"), fileContentsPtr.Length());
    }
 
  //Parse file line by line
  while((posNewLineDelim = fileContentsPtr.Find(newlineDelimeter)) != KErrNotFound )
     {
 
     RDebug::Print(_L("#### position newline %d"), posNewLineDelim);
     TPtrC8 line(fileContentsPtr.Mid(0,posNewLineDelim));
 
     HBufC *unicode = HBufC::NewLC(line.Length());
     TPtr16 p16 = unicode->Des();
 
     //convert to unicode
     CnvUtfConverter::ConvertToUnicodeFromUtf8( p16 , line );
 
     RDebug::Print(_L("#### Line %S"), &(*unicode));
 
     TPtrC16 key, value;
 
     //try to find key and value from the line of text
     ParseLine(*unicode, key, value);
 
     if(key.Length() > 0)
       {
	if(key.Compare(KVersion)==0) 
	   ; // do something with the version information 
 
        if(key.Compare(KText)==0) 
	   ; // do something with the text
       }		    	    
 
 
     fileContentsPtr =fileContentsPtr.Right( fileContentsPtr.Length() - (posNewLineDelim+newlineDelimeter.Length()));
     RDebug::Print(_L("#### remaining length %d"), fileContentsPtr.Length());
     CleanupStack::PopAndDestroy(unicode);
    }
 
    CleanupStack::PopAndDestroy(2,&file); //filecontents, file
    return KErrNone;            
    }
 
void CUTF8FileParser::ParseLine(const TDesC& aLine, TPtrC16& aKey, TPtrC16& aValue)
    {
    //one can easily implement comment option by skipping 
    //lines starting with specific character
 
    TLex lexer(aLine);
 
    lexer.SkipSpace(); //skip start space
 
    lexer.Mark();
    lexer.SkipCharacters();
 
    aKey.Set(lexer.MarkedToken()); //key
 
    lexer.SkipSpaceAndMark();
    aValue.Set(lexer.Remainder()); //value      
    }