From: Michael Smith <emmenjay AT zip DOT com DOT au>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: stderr | stdout > file
Date: Wed, 07 Apr 1999 01:42:25 +0900
Organization: Emmenjay Consulting
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Message-ID: <370A3971.7B4E@zip.com.au>
References: <3703B753 DOT 6FC4C8DE AT geocities DOT com>
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

The Beyonder wrote:
> 
> In DJGPP how can I pipe stderr or stdout to a file like foo.dmp?  I
> assumed something like:
> // code...
> stdout = fopen( "foo.dmp", "wt" );
> // code..
> 
> but DJGPP gives me:
> 
> non-something lvalue....

Do you mean: "invalid lvalue in assignment"?

If you want help, it's a good idea to take the extra three seconds to
write down the correct error message. 

Use freopen().


#include <stdio.h>
#include <stdlib.h>

const char *logname = "foo.dmp";

int main( void )
{
   char cmd[128];

   /* Reassign "stderr" to logname */
   if (!freopen( logname, "w", stderr )) {
      fprintf( stdout, "Error on freopen\n" );
      return 1;
   }

   fprintf( stderr, "Something for the logfile\n" );
   fclose( stderr );

   fprintf( stdout, "Finished executing: dumping %s\n", logname );

   sprintf( cmd, "type %s", logname );
   system( cmd );

   return 0;
}


-- 
########################################################################
Michael Smith                                        emmenjay AT zip DOT com DOT au
Emmenjay Consulting Pty Ltd             http://www.zip.com.au/~emmenjay/

Computers *ARE* user-friendly.  You just need to be properly introduced.