Determining if an OS is using 32 or 64 bits
This may be our number one question. Sadly I have not been able to find a definitive answer for Linux. If you have a Linux solution, please post it in our Linux forum. I will edit this post to include it.

32 / 64 bit (Solaris)
hp-ux (HP-UX )
command to check the bit (Solaris)
32-bit or 64-bit (Solaris, HP-UX, AIX)
64 or 32 bit kernel? (AIX)

C Programming Issues
Accessing large files from a 32 bit kernel on Solaris: Max file size can't exceed 2 GB
Accessing large file in LP64 mode on HP-UX: Unix file size - HP-UX and C++ Problem, managing >2Gb file
LP64 mode in general with a HP-UX example: Unsigned int

File System Size
Having a 64 bit kernel and a program compiled in 64 bit mode may not be enough. A particular file system may be be able to support large files. See: Unix file size - HP-UX

Here are some other threads and some web pages that might help...


other threads
change solaris to 32bit
random number logic -- issue
Use of unzip with content files > 2Gb
The Unix Crash of 2036
Please help me clear up some confusion

HP web site
HP-UX 64-bit Porting and Transition Guide
Interoperability of 32- and 64-bit applications on 64-bit HP-UX
HP-UX 64-bit porting concepts
64-Bit Runtime Architecture for PA-RISC 2.0

Sun web site
64-bit Computing Technical FAQ
Extending 32-bit Applications
Solaris 64-bit Developer's Guide
Booting Solaris Systems to Either the 64-Bit Kernel or the 32-Bit Kernel

Linux links
Linux Power PC 64
64-bit PowerPC ELF ABI Supplement
Intel® Developer Services Linux 64-bit
SUSE LINUX 9.1 Professional
Fedora Core 2 Install 64 Bit (4 CD Set)