If you are getting an error similar to "error while loading shared libraries: /u01/app/oracle/product/11.2" when trying to use the lsnrctl command in Oracle, it means that the system is unable to find the required shared libraries in the specified path.
To fix this problem, you can try the following steps:
Check if the shared libraries are indeed missing from the specified path. If they are missing, you can try re-installing Oracle or copying the missing libraries from another system.
Make sure that the Oracle environment variables are set correctly. You can check the environment variables by running the echo $ORACLE_HOME and echo $LD_LIBRARY_PATH commands. If the variables are not set correctly, you can set them by adding the appropriate lines to your .bashrc or .bash_profile file.
If the shared libraries are present and the environment variables are set correctly, you can try running the ldd command on the lsnrctl binary to see if there are any other missing libraries that are causing the error.
If none of the above steps help, you can try searching online for specific solutions for your version of Oracle and operating system.