Re: dup2

Hell all,

I was trying to redirect stdout to a file by using dup2. First I followed microsoft example: http://msdn.microsoft.com/en-us/library/8syseb29.aspx

it just works fine.

Then I tried to implement this in my own class (ABCLog) but stdout is not captured. I cannot figure it out. The only reason I could think of is that main() is in main.cpp while class ABCLog are in separate files (ABCLog.cpp and ABCLog.h). Could anybody confirm this please?

int main(int argc, char *argv[])
{
   ABCLog *log = new ABCLog();

   puts("in main");
   fflush( stdout );

   delete log;

   return 0;
}

ABCLog::ABCLog(const char *logFileName)

{
   old = _dup(1); /* "old" refers to stdout */
   if(old == -1) {
       perror(ERR_000104_DUP);
       exit(1);
   }

   if( fopen_s( &logFile, logFileName, "a" ) != 0 ) {
       fprintf(stderr, ERR_000105_LOG_FILE_OPEN, logFileName);
       exit( 1 );
   }

   if( -1 == _dup2( _fileno( logFile ), 1 ) ) {
       perror( ERR_000106_DUP2 );
       exit( 1 );
   }

   puts("in ABCLog");
   fflush(stdout);
}

/**
* Destructor
*/
ABCLog::~ABCLog()
{
   _dup2( old, 1 );
   _flushall();
   m_stream.close();
}