Example field procedure program

ALTER TABLE TESTTAB ALTER C1 SET FIELDPROC FP1(10)

#include "string.h"
#include <QSYSINC/H/SQLFP>
void reverse(char *in, char *out, long length);
main(int argc, void *argv[])
{
  short *funccode = argv[1];
  sqlfpFieldProcedureParameterList_T *optionalParms = argv[2];
  char *sqlstate = argv[7];
  sqlfpMessageText_T *msgtext = argv[8];
  int bytesToProcess;
  sqlfpOptionalParameterValueDescriptor_T *optionalParmPtr;

   if (optionalParms->sqlfpNumberOfOptionalParms != 1)
   {
      memcpy(sqlstate,"38001",5);
      return;
   }
   optionalParmPtr = (void *)&(optionalParms->sqlfpParmList);
   bytesToProcess = *((int *)&optionalParmPtr->sqlfpParmData);
   if (*funccode == 8)               /* create time */
   {
      sqlfpParameterDescription_T *inDataType = argv[3];
      sqlfpParameterDescription_T *outDataType = argv[5];
      if (inDataType->sqlfpSqlType !=452 && 
          inDataType->sqlfpSqlType !=453 )   /* only support fixed length char */
      {
         memcpy(sqlstate,"38002",5);
         return;
      }
      /* do something here to determine the result data type */
      /* ..... */
      /* in this example input and output types are exactly the same */
      /* so just copy */
      memcpy(outDataType, inDataType, sizeof(sqlfpParameterDescription_T));
   }
   else if (*funccode == 0)      /* encode */
   {
      char *decodedData = argv[4];
      char *encodedData = argv[6];

      reverse(decodedData, encodedData, bytesToProcess);
   }
   else if (*funccode == 4)    /* decode */
   {
     char *decodedData = argv[4];
     char *encodedData = argv[6];

     reverse(encodedData, decodedData, bytesToProcess);
   }
   else  /* unsupported option -- error */
      memcpy(sqlstate, "38003",5);
}

void reverse(char *in, char *out, long length)
{
    int i;
    for (i=0;i<length; ++i) {
      out[length - (i+1)] = in[i]; 
    }
}