You can check the versions of the compiler and individual filesets installed by using the lslpp command, the -qversion compiler option, or by viewing the .vrmf_history file.
lslpp option_string
where option_string can
be: To get more details about the version, release, and PTF levels of the compiler, you can use the -qversion compiler option. For more information, see -qversion in the XL C/C++ Compiler Reference.
If you have installed XL C/C++ to a non-default location, you can view the version information for each fileset installed by viewing the .vrmf_history text file that is installed in the compiler's main directory.