LIXA provides a configuration utility named lixa-config. It can be used to retrieve some useful information necessary for other shell commands. Try it with --help parameter:

[tiian@centos lixa]$ /opt/lixa/bin/lixa-config --help
Usage:
  lixa-config [OPTION...] - LIXA config utility

Help Options:
  -h, --help                       Show help options

Application Options:
  -c, --cflags                     [-Wall]
  -C, --config-dir                 [/opt/lixa/etc]
  -f, --cppflags                   [-I/opt/lixa/include]
  -i, --include-dir                [/opt/lixa/include]
  -d, --ldflags                    [-Wl,-rpath -Wl,/opt/lixa/lib]
  -L, --lib-dir                    [/opt/lixa/lib]
  -l, --libs                       [-L/opt/lixa/lib -llixac]
  -o, --include-dir-postgresql     [/usr/include]
  -p, --libs-postgresql            [-L/opt/lixa/lib -llixac -llixapq]
  -y, --include-dir-mysql          [/usr/include/mysql]
  -m, --libs-mysql                 [-L/opt/lixa/lib -llixac -llixamy]
  -P, --prefix                     [/opt/lixa]
  -s, --state-dir                  [/opt/lixa/var]
  -r, --rsrc-mngrs                 list of configured Resource Managers
      

If you need to set a variable with the path containing LIXA libraries, simply use something like:

[tiian@centos lixa]$ export FOOBAR=$(/opt/lixa/bin/lixa-config --lib-dir)
[tiian@centos lixa]$ echo $FOOBAR
/opt/lixa/lib
      

It may be useful when you installed two different version of LIXA inside the same host: pointing the right lixa-config is sufficient to retrieve all the correlated info.