Error reported when executing isql in Linux sybase

After sybase 12.5.4 is installed on RedHat as 4 and Initialization is complete, run isql-Usa-P to report the error:

The context allocation routine failed when it tried to load localization files !!
One or more following problems may caused the failure

Your sybase home directory is/opt/sybase-12.5. Check the environment variable SYBASE if it is not the one you want!
Using locale name "zh_CN.UTF-8" defined in environment variable LANG
Locale name "zh_CN.UTF-8" doesn't exist in your/opt/sybase-12.5/locales. dat file
An error occurred when attempting to allocate localization-related structures

This is because LANG settings are incorrect. Execute export LANG = C and execute again
Isql-Usa-P
Or error:
CT-LIBRARY errors:
Ct_connect (): directory service layer: internal directory control layer error: Requested server name not found.

This is because the parameter is incorrect. Add the parameter-S to execute the server name.

Isql-Usa-P-Ssybase
Execution successful