Re: [Boost-bugs] [Boost C++ Libraries] #4824: Boost file system function file_size() function is returning 0 for /proc virtual file system files. (was: tellg () function of ifstream object is returning -1 for /proc virtual file system files.)

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #4824: Boost file system function file_size() function is returning 0 for /proc virtual file system files. (was: tellg () function of ifstream object is returning -1 for /proc virtual file system files.)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-11-10 15:55:32

#4824: Boost file system function file_size() function is returning 0 for /proc
virtual file system files.
----------------------------------+-----------------------------------------
  Reporter:  pmanth2@…            |       Owner:  bemandawes
      Type:  Bugs                 |      Status:  new       
 Milestone:  To Be Determined     |   Component:  filesystem
   Version:  Boost 1.44.0         |    Severity:  Problem   
Resolution:                       |    Keywords:            
----------------------------------+-----------------------------------------

Comment (by anonymous):

 The boost filesystem function file_size returning 0 for /proc file system
 files. Below is the example program to demonstrate the problem.

 #include <boost/filesystem/operations.hpp>
 #include <iostream>

 namespace fs = boost::filesystem;

 int main( int argc, char* argv[] )
 {

   if ( argc != 2 )
   {
     std::cout << "Usage: file_size path\n";
     return 1;
   }

   fs::path p( argv[1], fs::native );

   if ( !fs::exists( p ) )
   {
     std::cout << "not found: " << argv[1] << std::endl;
     return 1;
   }

   if ( !fs::is_regular( p ) )
   {
     std::cout << "not a regular file: " << argv[1] << std::endl;
     return 1;
   }

   std::cout << "size of " << argv[1] << " is " << fs::file_size( p )
 ---------- boost file system file_size function
     << std::endl;
   return 0;
 }

 Output:

 pmanth2_at_cyder:~/new-saga-code/trunk/adaptors/default/file$ ./new k
 size of k is 46
 pmanth2_at_cyder:~/new-saga-code/trunk/adaptors/default/file$ wc -c k
 46 k
 pmanth2_at_cyder:~/new-saga-code/trunk/adaptors/default/file$ wc -c
 /proc/cpuinfo
 10102 /proc/cpuinfo
 pmanth2_at_cyder:~/new-saga-code/trunk/adaptors/default/file$ ./new
 /proc/cpuinfo
 size of /proc/cpuinfo is 0   --------------------- ( should return actual
 size of file just as word count )

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/4824#comment:1>
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