Example of a user exit program

a) Content of userexit.c:

 #include <windows.h> 
 #include <stdio.h> 
 #include <stdlib.h> 
 #include <string.h> 

/* USER_EXITINFO struct */ 
typedef struct user_exitinfo { 
 int whereno; /* Extraction condition number */ 
 int outfileno; /* Output file number */ 
 char outitemname[255+1]; /* Output field name */ 
 int outitemno; /* Output field number */ 
 char outitemtype; /* Definition field type */ 
 int outitemsize; /* Definition field size */ 
 char outitemflg; /* Digits after decimal point of the definition */ 
}USER_EXITINFO; 

/* Function that obtains data corresponding to the field number */ 
typedef int (__stdcall *PROC_ed_getindata_itemno) (void *ptr1, void *ptr2, int itemno, char **getbuf, int *getsize); 

/* Function that obtains the memory */ 
typedef void *(__stdcall *PROC_ed_malloc) (size_t size); 

/* Function that releases the memory */ 
typedef void (__stdcall *PROC_ed_free)(void *ptr); 

/* DLL entry point */ 
BOOL APIENTRY DllMain( HANDLE hModule, 
                   DWORD ul_reason_for_call, 
                   LPVOID lpReserved ) 
{ 
switch (ul_reason_for_call){ 
       case DLL_PROCESS_ATTACH: 
       case DLL_THREAD_ATTACH: 
       case DLL_THREAD_DETACH: 
       case DLL_PROCESS_DETACH: 
           break; 
} 
   return TRUE; 
} 

/* Initial processing function */ 
int __stdcall ed_userexit_init( short *dtlerrno ) 
{
 return 0; 
} 

/* Main function */ 
int __stdcall ed_userexit_main( USER_EXITINFO *user_exitinfo, 
                           char **outbuf, 
                           int *outsize, 
                           short *dtlerrno, 
                           void *ptr1, 
                           void *ptr2 ) 
{ 
/* For obtaining data */ 
char *getbuf; 
/* For storing data size */ 
int getsize = 0; 
/* For storing module handle */ 
HMODULE hModule; 
/* Function that obtains data corresponding to the field number*/ 
PROC_ed_getindata_itemno ed_getindata_itemno; 
/* Function to obtain memory */ 
PROC_ed_malloc ed_malloc; 
/* Function to release memory */ 
PROC_ed_free ed_free; 

/* Loading the function to obtain the input data */ 
hModule = GetModuleHandle(NULL); 
ed_getindata_itemno = 
(PROC_ed_getindata_itemno)GetProcAddress(hModule, "ed_getindata_itemno"); 
if( ed_getindata_itemno == NULL ){
       *dtlerrno = 1; 
       return -1; 
} 

/* Loading the function to obtain memory */ 
ed_malloc = (PROC_ed_malloc)GetProcAddress(hModule, "ed_malloc"); {
if( ed_malloc == NULL ){
       *dtlerrno = 2; 
       return -1; 
} 

/* Loading the function to release memory */ 
ed_free = (PROC_ed_free)GetProcAddress(hModule, "ed_free"); 
if( ed_free == NULL ){ 
       *dtlerrno = 3; 
       return -1; 
} 

/* Obtaining the data corresponding to the field number 1 */ 
if( ed_getindata_itemno( ptr1, ptr2, 1, &getbuf, &getsize ) != 0 ){ 
       *dtlerrno = 4; 
       return -1; 
} 

/* Allocating the output buffer*/ 
*outbuf = (char *)ed_malloc( 64 ); 
if( *outbuf == NULL ){ 
       *dtlerrno = 5; 
       return -1; 
} 
sprintf((char *)*outbuf,
 "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", 
 (unsigned char)getbuf[0],(unsigned char)getbuf[1],  
 (unsigned char)getbuf[2],(unsigned char)getbuf[3], 
 (unsigned char)getbuf[4],(unsigned char)getbuf[5], 
 (unsigned char)getbuf[6],(unsigned char)getbuf[7], 
 (unsigned char)getbuf[8],(unsigned char)getbuf[9], 
 (unsigned char)getbuf[10],(unsigned char)getbuf[11], 
 (unsigned char)getbuf[12],(unsigned char)getbuf[13], 
 (unsigned char)getbuf[14],(unsigned char)getbuf[15]); 
*outsize=32; 

/* Releasing the obtained data */ 
ed_free( getbuf ); 

return 0; 
} 

/* End function */ 
void ed_userexit_end( void ) 
{ 
return; 
}   

b) Content for userexit.def

 LIBRARY "userexit" 

EXPORTS 
 ed_userexit_init @1 
 ed_userexit_main @2 
 ed_userexit_end @3

a) Content of userexit.c

#include <stdio. h> 
#include <stdlib. h> 

/* USER_EXITINFO struct */ 
typedef struct user_exitinfo { 
 int whereno; /* Extraction condition number */ 
 int outfileno; /* Output file number */ 
 char outitemname[255+1]; /* Output field name */ 
 int outitemno; /* Output field number */ 
 char outitemtype; /* Definition field type */ 
 int outitemsize; /* Definition field size */ 
 char outitemflg; /* Digits after decimal point of the definition */ 
} USER_EXITINFO; 

/* Function that obtains data corresponding to the field number */ 
int *ed_getindata_itemno ( void *ptr1, void *ptr2, int itemno, 
                     char **getbuf, int *getsize); 
void *ed_malloc (size_t size); 
void ed_free (void *ptr); 

/* Initial processing function */ 
int ed_userexit_init( short *dtlerrno ) 
{ 
 return 0; 
} 

/* Main function */ 
int ed_userexit_main( USER_EXITINFO *user_exitinfo, 
                  char **outbuf, 
                  int *outsize, 
                  short *dtlerrno, 
                  void *ptr1, 
                  void *ptr2 ) 
{ 
char *getbuf; /* For obtaining data */ 
int getsize = 0; /* For storing data size */ 
/* Obtaining the data corresponding to the field number 1 */ 
if( ed_getindata_itemno( ptr1, ptr2, 1, &getbuf, &getsize ) != 0 ){ 
        *dtlerrno = 1; 
        return -1; 
} 

/* Allocating the output buffer*/ 
*outbuf = (char *)ed_malloc( 64 ); 
if( *outbuf == NULL ){ 
     *dtlerrno = 2; 
     return -1; 
} 
sprintf((char *)*outbuf, 
 "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", 
 (unsigned char)getbuf[0],(unsigned char)getbuf[1],  
 (unsigned char)getbuf[2],(unsigned char)getbuf[3], 
 (unsigned char)getbuf[4],(unsigned char)getbuf[5], 
 (unsigned char)getbuf[6],(unsigned char)getbuf[7], 
 (unsigned char)getbuf[8],(unsigned char)getbuf[9], 
 (unsigned char)getbuf[10],(unsigned char)getbuf[11], 
 (unsigned char)getbuf[12],(unsigned char)getbuf[13], 
 (unsigned char)getbuf[14],(unsigned char)getbuf[15]); 
*outsize=32; 

/* Releasing the obtained data */ 
ed_free( getbuf ); 

return 0; 
} 

/* End function */ 
void ed_userexit_end( void ) 
{ 
return; 
}