In a number of places in the filesystem library on Linux, the ::stat file system call is used. When this call is executed on a file whose size is larger than 2GB, it fails because the file size cannot fit into the default "stat" structure. This problem happens even when the size information in the stat structure is not used. For example the stat information is used in the directory iterator to look for sub directories. This can be corrected by setting the macro _FILE_OFFSET_BITS to 64. What is the best way to set this macro on Linux? I have looked at the jam rules and cannot locate the appropriate place to include the definition. Also, what process should be followed if I want to have this macro defined either by default or at least as an option in the boost source tree so that I don't have to modify the build rules each time I install boost?