Enable global automatic text conversion (AUTOCVT)?

Activates or deactivates automatic conversion of I/O data using coded character sets for the program and its associated files. The coded character set identifiers (CCSIDs) are specified by the program itself or by setting the appropriate environment variables at run time. This system AUTOCVT indicator can be overridden by individual programs at a thread level. AUTOCVT is therefore a controlling switch only for existing programs which do not explicitly establish their own conversion environment.

Default: AUTOCVT(NO)

You can change the value of AUTOCVT between YES and NO using the SETOMVS or SET OMVS commands. Changing this conversion mode does not affect conversion of opened files for which I/O has already started.

When AUTOCVT(YES) is set, every read or write operation for a file must be checked to see if conversion is necessary. Thus, there is a performance penalty involved, even if no conversion occurs. It is therefore preferable to keep AUTOCVT(NO) and have each program enabled, if possible, for conversion. This can be accomplished by setting the compile time or run time environment variables that control conversion, or by issuing fcntl().