I have a raspberry pi board conencted to xbee device via usb adapter. ie: To access my xbee, it will be /dev/ttyUSB. I want to use xbee ansic library api's to send and receive commands from/to my xbee device. Have downloaded xbee ansic library code from https://github.com/digidotcom/xbee_ansic_library.git
It was designed for building complete, stand-alone programs. It targets embedded systems without an OS, where you compile a single program to run on the processor. I guess it's possible to modify it to build a library, but in many instances you have compile-time configuration going on.
Your USB interface is essentially serial once it gets to the XBee module. Just specify the correct /dev/tty device.
You'll have to look up the documentation of the device. Some modules report on their internal temperature (which is likely higher than ambient) using remote AT commands.