Writing a custom conversion routine

A custom character set conversion routine is defined as follows:

CS_RETCODE convfunc(context, srcfmt, srcdata,
               destfmt, destdata, destlen)
 CS_CONTEXT        *context;
 CS_DATAFMT        *srcfmt;
 CS_VOID               *srcdata;
 CS_DATAFMT       *destfmt;
 CS_VOID              *destdata;
 CS_INT                 *destlen;

where:

• context is a pointer to a CS_CONTEXT structure.

• srcfmt is a pointer to a CS_DATAFMT structure describing the source data. srcfmt→maxlength describes the actual length, in bytes, of the source data.

• srcdata is a pointer to the source data.

• destfmt is a pointer to a CS_DATAFMT structure describing the destination data. destfmt→maxlength describes the actual length, in bytes, of the destination data space.

• destdata is a pointer to the destination data space.

• destlen is a pointer to an integer. If the conversion is successful, the custom routine should set *destlen to the number of bytes placed in *destdata.

cs_config is the only CS-Library, Client-Library, or Server-Library routine that can be called from within a custom conversion routine.

CS-Library raises a CS-Library error if the custom routine returns any value other than CS_SUCCEED. The type of error that CS-Library raises depends on the value that the custom routine returns.