Integrating custom conversion functions

Custom-conversion functions are loaded into the onpload executable command through a shared library.

About this task

To integrate your custom-conversion functions into the onpload executable command:

Procedure

  1. Prepare the custom-conversion function table.

    The onpload utility uses the entries in a function table to translate custom-function string names that are specified in the load or unload map. You must supply the function table and the custom-conversion functions.

    To code the function table, use the following template for the file plcstcnv.c. You can copy this template from the $INFORMIXDIR/incl/hpl directory. Add as many entries into the functiontable array as needed.

    The onpload utility searches the functiontable array for the string name of the custom-conversion function that the map specifies. The function pointer that is associated with the string name is retrieved and used as the custom-conversion function. In the following template for the file plcstcnv.c, ycf1 and ycf2 are the strings that ipload uses to find the custom functions your_conversion_func1 and your_conversion_func2. To add custom function string names to the onpload database, see Mapping options.
    /*
 * plcstcnv.c
 */
#include "pldriver.h"

extern int your_conversion_func1();
extern int your_conversion_func2();

struct functable functiontable[] =
{
{"ycf1", your_conversion_func1},
{"ycf2", your_conversion_func2},
{0, 0}
};
/* end of plcstcnv.c */
  2. Prepare your conversion functions. Use the template in the following example to code your conversion functions: 
    /*
 * your_custom_conversion.c
 */

/*
 * The argument list must be adhered to.
 */
int your_conversion_func1(outbuffer, buflen, value)
char *outbuffer; /* where to put your output */
intbuflen;/* max size of buffer in bytes*/
char *value; /* input value */
{
/* your processing here */
}

int your_conversion_func2(outbuffer, buflen, value)
char *outbuffer; /* where to put your output */
intbuflen;/* max size of buffer */
char *value; /* input value */
{
/* your processing here */
}
/* end of your_custom_conversion.c */
  3. Rebuild the onpload shared-library file ipldd11a.SOLIBSUFFIX, (where SOLIBSUFFIX is the shared-library suffix for your platform).
    Follow the instructions in Rebuilding the shared-library file.

    The onpload utility uses the same library for both custom-conversion functions and custom drivers. When you rebuild the library, if there are custom drivers, you must link the custom-driver code as well as the custom-conversion functions.

  4. Install the shared library in the appropriate path for your platform.
    For example, on Solaris the shared library should be installed in $INFORMIXDIR/lib or any configurable path that is specified by the HPL_DYNAMIC_LIB_PATH configuration parameter.