We distribute in Linux a static lib in both 64-bit and 32-bit versions.  When troubleshooting a customer, I would like my diagnostic shell script to quickly eliminate the issue by checking the .a archive file to detetmine whether it is 32 or 64 bit.  The methods that occur to me are less than elegant:

objdump seems like the best way:
objdump -f libfoo.a | grep ^architecture

