Encoding problems with sqlplus, Linux I use sqlplus and all non-Latin characters appear as '?' when I run select queries. When I run insert or update queries with non-Latin characters I get question marks on a web page.

select * from nls_database_parameters; gives NLS_CHARACTERSET: AL32UTF8.
I've exported the NLS_LANG variable: export NLS_LANG=RUSSIAN_CIS.AL32UTF8, but this didn't make any changes.

What is the problem? Of course I use UTF-8 working in Linux terminal and I can see the script file contents executing cat script.sql.

If I execute alter session set nls_language='russian' I also face with question marks in ora-xxxxx messages.
since you confirmed the character set in the database is AL32UTF8, you need to make sure the fonts is installed on the Linux machine, and install the message libraries. that will make ORA_NLS33 has been set appear when you execute alter session set nls_language=