cs_will_convert

Description

Indicates whether a specific datatype conversion is available in the Client/Server libraries.

Syntax

CS_RETCODE cs_will_convert(context, srctype, desttype,
                result)
 
 CS_CONTEXT     *context;
 CS_INT                srctype;
 CS_INT                desttype;
 CS_BOOL            *result;

Parameters

context: A pointer to a CS_CONTEXT structure.

srctype: A symbolic constant representing the datatype of the source data (for example, CS_BYTE_TYPE, CS_CHAR_TYPE, and so forth).

desttype: A symbolic constant representing the datatype of the destination data.

result: A pointer to a boolean variable. cs_will_convert sets *result to CS_TRUE if the datatype conversion is supported and CS_FALSE if the datatype conversion is not supported.

Returns

cs_will_convert returns:

Returns	Indicates
CS_SUCCEED	The routine completed successfully.
CS_FAIL	The routine failed.

Examples

Example 1

/*

 ** ex_display_column()

*/

CS_RETCODE CS_PUBLIC

 ex_display_column(context, colfmt, data, datalength,

      indicator)

 CS_CONTEXT           *context;

 CS_DATAFMT           *colfmt;

 CS_VOID              *data;

 CS_INT               datalength;

 CS_SMALLINT          indicator;

    char         *null = "NULL";

    char         *nc   = "NO CONVERT";

    char         *cf   = "CONVERT FAILED";

    CS_DATAFMT   srcfmt;

    CS_DATAFMT   destfmt;

    CS_INT       olen;

    CS_CHAR      wbuf[MAX_CHAR_BUF];

    CS_BOOL      res;

    CS_INT       i;

    CS_INT       disp_len;

 if (indicator == CS_NULLDATA)

     olen = strlen(null);

     strcpy(wbuf, null);

 else

     cs_will_convert(context, colfmt->datatype,

          CS_CHAR_TYPE, &res);

     if (res != CS_TRUE)

        olen = strlen(nc);

        strcpy(wbuf, nc);

 		else

        srcfmt.datatype  = colfmt->datatype;

        srcfmt.format    = colfmt->format;

        srcfmt.locale    = colfmt->locale;

        srcfmt.maxlength = datalength;

        destfmt.maxlength = MAX_CHAR_BUF;

        destfmt.datatype  = CS_CHAR_TYPE;

        destfmt.format    = CS_FMT_NULLTERM;

        destfmt.locale    = NULL;

        if (cs_convert(context, &srcfmt, data,

           &destfmt, wbuf, &olen) != CS_SUCCEED)

           olen = strlen(cf);

           strcpy(wbuf, cf);

        else

/*

           ** output length include null

           ** termination

*/

           olen -= 1;

 fprintf(stdout, "%s", wbuf);

 disp_len = ex_display_dlen(colfmt);

 for (i = 0; i < (disp_len - olen); i++)

    fputc(' ', stdout);

    return CS_SUCCEED;

Usage

cs_will_convert allows an application to determine whether cs_convert or ct_bind/ct_fetch are capable of performing a specific conversion. When cs_convert is called to perform a conversion that it does not support, it returns CS_FAIL and generates a CS-Library error.

cs_convert can convert between standard and user-defined datatypes. To enable these types of conversions, an application must install custom conversion routines through cs_set_convert. If a custom routine is supplied for a conversion, cs_will_convert indicates that the conversion is supported.

Datatype conversion chart

A chart listing the datatype conversions that cs_convert supports is included on the manual page for cs_convert. (See Table 2-3.)