Exchanging itabs between C and ABAP using RFC

Question

Hello,
how can I send an internal table from ABAP to a C or C++ client, modify it here and send that modified table back to ABAP?
Thx for your help!
Thomas

Answer 1

Here is my coding. Does anybody have an idea why the pointer in line 151 is = NULL ?
Thx
Tom
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <saprfc.h>
#include <sapitab.h>
static RFC_RC remote_function (RFC_HANDLE handle);
static RFC_RC install (RFC_HANDLE handle);
RFC_HANDLE handle;
typedef struct RFCSTRUCT {
  RFC_INT   seq;
  RFC_FLOAT m;
  RFC_FLOAT si;
  RFC_FLOAT sl;
  RFC_INT   id;
  RFC_INT   lo;
  RFC_FLOAT re;
} rfcstruct;
static RFC_TYPEHANDLE handleRFCSTRUCT;
static RFC_TYPE_ELEMENT typeRFCSTRUCT[] = {
  /* name /         / type /  / length /        / decimals */
  { "SEQ",        TYPINT,     sizeof(RFC_INT),    0 },
  { "M",          TYPFLOAT,   sizeof(double),     16 },
  { "SI",         TYPFLOAT,   sizeof(double),     16 },
  { "SL",         TYPFLOAT,   sizeof(double),     16 },
  { "ID",         TYPINT,     sizeof(RFC_INT),    0 },
  { "LO",         TYPINT,     sizeof(RFC_INT),    0 },
  { "RE",         TYPFLOAT,   sizeof(double),     16 },
#define ENTRIES( tab ) ( sizeofR(tab)/sizeofR((tab)[0]) )
Main
int main (int argc, char ** argv)
  RFC_RC rc;
  handle = RfcAccept(argv);
  rc = install(handle);
  if (rc != RFC_OK)
    RfcAbort(handle,"Initialization error");
    return(1); }
  do{
    rc = RfcDispatch(handle);
  } while (rc == RFC_OK);
  RfcClose(handle);
  return(0); }
install()
static RFC_RC install(RFC_HANDLE handle) {
  RFC_RC rfc_rc;
  rfc_rc = RfcInstallFunctionExt( handle,
                                 "FUNC",
                                 (RFC_ONCALL)remote_function,
                                  "nodocu" );
  if (rfc_rc != RFC_OK)
    return rfc_rc;
  return RFC_OK;
remote function
static RFC_RC remote_function (RFC_HANDLE handle) {
  RFC_RC rfc_rc;
  ITAB_H itab_handle;
  RFC_PARAMETER Exporting[0];
  RFC_PARAMETER Importing[0];
  RFC_TABLE Table[1];
  Exporting[0].name = NULL;
  Importing[0].name = NULL;
rfc_rc = RfcInstallStructure(  "rfcstruct",
                                typeRFCSTRUCT,
                                ENTRIES(typeRFCSTRUCT),
                                &handleRFCSTRUCT);
  itab_handle = ItCreate("ITAB", sizeof(rfcstruct), 0, 0);
  Table[0].name = "ITAB";
  Table[0].nlen = strlen("ITAB");
  Table[0].type = handleRFCSTRUCT;          
  Table[0].leng = sizeof(rfcstruct);
  Table[0].itmode = RFC_ITMODE_BYREFERENCE; 
  Table[0].ithandle = itab_handle;
  Table[1].name = NULL;
  rfc_rc = RfcGetData(handle, Importing, Table);
  if (rfc_rc != RFC_OK)
    return (rfc_rc);
  modify_table(itab_handle, handle);   
  rfc_rc = RfcSendData(handle, Exporting, Table);  
  return(rfc_rc);
  ItFree(itab_handle);
  RfcClose(handle);
modity itab...
modify_table(ITAB_H itab_handle, RFC_HANDLE handle) {
  int linenr;
  int lineleng;
  char table_data[8192]; 
  struct RFCSTRUCT *ptr=NULL;
  RFC_FLOAT a;
  RFC_FLOAT s;
  RFC_FLOAT sl;
  RFC_INT id;
  RFC_INT lo;
  lineleng = ItLeng(itab_handle);
  for (linenr = 1; ; linenr++)
    ptr = ( struct RFCSTRUCT  *) ItGetLine(itab_handle, linenr);
    /* HERE: POINTER IS ALWAYS == NULL - WHAT'S WRONG ??? */
    if (ptr == NULL) break;
    memcpy(table_data, ptr, lineleng);
  return; }