Hello.
It looks like sqlcl (4.2.0.15.177.0246) ignores predefined variable NLS_LANG and uses system setting for it:
C:\Users\admitr>set NLS
Environment variable NLS not defined
C:\Users\admitr>set NLS_LANG=AMERICAN_AMERICA.CL8MSWIN1251
C:\Users\admitr>Apps\sqlcl\bin\sql admitr@dev1
SQLcl: Release 4.1.0 Release Candidate on тЄ ўхЁт. 30 14:43:33 2015
Copyright (c) 1982, 2015, Oracle. All rights reserved.
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Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ADMITR @ dev1> select * from nls_session_parameters;
PARAMETER VALUE
NLS_LANGUAGE UKRAINIAN
NLS_TERRITORY UKRAINE
NLS_CURRENCY уЁэ.
NLS_ISO_CURRENCY UKRAINE
NLS_NUMERIC_CHARACTERS ,
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD.MM.RRRR
NLS_DATE_LANGUAGE UKRAINIAN
NLS_SORT UKRAINIAN
NLS_TIME_FORMAT HH24:MI:SSXFF
NLS_TIMESTAMP_FORMAT DD.MM.RRRR HH24:MI:SSXFF
NLS_TIME_TZ_FORMAT HH24:MI:SSXFF TZR
NLS_TIMESTAMP_TZ_FORMAT DD.MM.RRRR HH24:MI:SSXFF TZR
NLS_DUAL_CURRENCY ъЁс.
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE
17 rows selected
ADMITR @ dev1>