https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html

Oracle Linux 7

https://docs.oracle.com/en/database/oracle/oracle-database/21/lacli/install-instant-client-using-rpm.html

sudo yum list|grep  oracle|grep sqlplus
sudo yum install oracle-instantclient18.3-sqlplus
export ORACLE_HOME=/usr/lib/oracle/18.3/client64/
export LD_LIBRARY_PATH="$ORACLE_HOME"/lib
export PATH="$ORACLE_HOME:$PATH"
export PATH=/usr/lib/oracle/18.3/client64/bin:$PATH

Additionally, you may have to perform the following tasks before you start your application:

• If you intend to colocate optional Oracle configuration files such as tnsnames.ora, sqlnet.ora, ldap.ora, or oraaccess.xml with Oracle Instant Client, then move these files to the /usr/lib/oracle/21/client64/lib/network/admin subdirectory.This is the default Oracle configuration directory for applications linked with this Oracle Instant Client.Alternatively, you can move the Oracle configuration files to another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.
• To use binaries from the tools package, use yum or dnf to install the package and then update your PATH environment variable. For example:Copy$ export PATH=/usr/lib/oracle/21/client64/bin:$PATH