g++ throwing file not recognized: File format not recognized error

Question

getting following error with the command g++ -o test -L . -l pq

libpq.so: file not recognized: File format not recognized

#file libpq.so
libpq.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), not stripped

gcc version 4.1.2 20070115 (SUSE Linux)

I am getting the same error if I try to use -l dbodbc instead of -l pq.

Note that test.c is a simple hello world program.

Thanks in Advance.

Answer 1

file /usr/bin/g++ tells you that g++ itself is a 64-bit executable, i.e. it runs on a 64-bit machine, it doesn't tell you that g++ can compile 64-bit code (it's very unlikely but it could be a cross compiler for a completely different processor!) Use g++ -v or g++ -dumpmachine to find out what target it generates executables for.

G++ doesn't actually use that library, it just passes the -l option to the linker, so the error is coming from the linker, ld

If ld and objdump are both saying they can't recognize the library but the same file is fine on a different machine, I would try updating or reinstalling the binutils package, which provides both ld and objdump.

You might have a 32-bit binutils installed, so its ld and objdump wouldn't understand the x86_64 library. Ensure you have the 64-bit (i.e. x86_64) binutils RPM installed.