Re: Standard C++ file size ???

On 7/6/2010 1:26 PM, James Kanze wrote:

I adapted your code to my style making minor formatting changes and
tested it on several files. It worked perfectly. What I liked best about
your code is that it taught me a very simple way to use exceptions.

I had previously avoided exceptions because their typical implementation
was far too convoluted, and I always strive for the simplest possible
code. Now that I know how to throw and catch text based exceptions they
are very simple. That was the cleanest error handling that I have ever
seen. This will become my new idiom for file processing and error handlin=

#include <iostream>
#include <fstream>
#include <vector>

void readAll(char const* filename, std::vector< char >& data ) {
std::ifstream fin;
   fin.open(filename, std::ios_base::in | std::ios_base::binary);
   if ( ! fin )
     throw "cannot open";

   fin.seekg( 0, std::ios::end );
   if ( ! fin )
     throw "seek error";

   long long size = fin.tellg();
   std::cout << filename << ": size = " << size << std::endl ;

   if ( size != 0 ) {
     fin.clear() ;

     fin.seekg( 0, std::ios::beg );
     if ( ! fin )
       throw "rewind failed";

     data.resize( size );
     fin.read( &data[ 0 ], size );
     if ( ! fin )
       throw "read failed";
   }

}

int main( int argc, char** argv ) {
std::vector< char > data;
   if (argc == 2)
     try {
       readAll( argv[ 1 ], data );
     } catch ( char const* error ) {
       std::cout << argv[ 1 ] << ": " << error << std::endl ;
     }
   else
     std::cout << "Must specify a FileName!" << std::endl ;
   return 0;

}