How can I get gcc to write a file larger than 2.0 GB?

Solution 1:

A simple #define seems to be all that is needed.. (the program writes past 2 GB now.)

Perhaps the reason it didn't compile apppropriately, is that I compiled a single program from a much larger suite ('xxd' is part of 'vim')...

Had I compiled 'vim' in toto, it would most likely have worked fine...

So for anyone who comes to this page, the following may be of some value:
I assume similar settings would apply to other IDEs.

Adding #defines

* Using CodeBocks (as a global setting)
  =====================================
  Settings
    Compiler and Debugger...
      [Compiler Settings]
        [#defines] ... Add the following
         _FILE_OFFSET_BITS="64"

* Using CodeBlocks (for a given Project)
  ======================================
  Properties
    Build Options
      [Compiler Settings]
        [#defines] ... Add the following
         _FILE_OFFSET_BITS="64"

* Directly into gcc's command line
  ================================
  gcc -D_FILE_OFFSET_BITS="64"

* Add a #define directly to the source
  ====================================
  #define _FILE_OFFSET_BITS  64  

Also, I discovered this snippet while googling for the solution...
What macros are predefined by gcc? ... in the terminal:

• touch foo.h; cpp -dM foo.h

Solution 2:

I recommend adding -D_GNU_SOURCE as long as #include <features.h> is used. This will enable all the largefile support. Read the beginning of /usr/include/features.h for more details:

...
_LARGEFILE_SOURCE    Some more functions for correct standard I/O.
_LARGEFILE64_SOURCE  Additional functionality from LFS for large files.
_FILE_OFFSET_BITS=N  Select default filesystem interface.
....
_GNU_SOURCE      All of the above, plus GNU extensions.