sqlplus: error while loading shared libraries: libsqlplus.so: cannot open shared object file: No such file or directory

The minimum configuration to properly run sqlplus from the shell is to set ORACLE_HOME and LD_LIBRARY_PATH. For ease of use, you might want to set the PATH accordingly too.

Assuming you have unzipped the required archives in /opt/oracle/instantclient_11_1:

$ export ORACLE_HOME=/opt/oracle/instantclient_11_1
$ export LD_LIBRARY_PATH="$ORACLE_HOME"
$ export PATH="$ORACLE_HOME:$PATH"

$ sqlplus

SQL*Plus: Release 11.1.0.7.0 - Production on Wed Dec 31 14:06:06 2014
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