Question: I have a requirement to Identify whether a Firebird system is 64 bit or not,in order to know whether to deploy a 64 bit UDF or a 32 bit UDF. Is there any thing to give the correct information?
The best Answer: Identify this information this way:
fbsvcmgr service_mgr -user sysdba -password masterke -info_server_version -info_implementation

see the manual for more  :

On ubuntu/debian 64 will give :
fbsvcmgr service_mgr -user sysdba -password masterke -info_implementation | grep 64
Server implementation: Firebird/linux AMD64

or you can count if the 64 string is present with -c in grep (notice that there is no need for username and password)

fbsvcmgr service_mgr -info_implementation | grep -c 64