This example shows the running of the ILE C trigger program when a record is deleted in the ATMTRANS file.
/**************************************************************/
/* Program Name - DELTRG */
/* This program is called when a delete operation occurs in */
/* the ATMTRANS file. */
/* */
/* This program will delete the records from ATMS and ACCTS */
/* based on the ATM ID and ACCT ID that are passed in from */
/* the trigger buffer. */
/* */
/* The application will delete ATMID 10003 from the ATMTRANS */
/* file. */
/* */
/**************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <recio.h>
#include "applib/csrc/msghandler" /* message handler include */
#include "qsysinc/h/trgbuf" /* trigger buffer include without*/
/* old and new records */
Qdb_Trigger_Buffer_t *hstruct; /* pointer to the trigger buffer */
char *datapt;
#define KEYLEN 5
/**************************************************************/
/* Need to define file structures here since there are non- */
/* character fields in each file. For each non-character */
/* field, C requires boundary alignment. Therefore, a _PACKED */
/* struct should be used in order to access the data that */
/* is passed to the trigger program. */
/* */
/**************************************************************/
/** record area for ATMTRANS **/
_Packed struct rec {
char atmid[5];
char acctid[5];
char tcode[1];
char amount[5];
} oldbuf, newbuf;
/** record area for ATMS **/
_Packed struct rec1{
char atmn[5];
char locat[2];
char atmamt[9];
} atmfile;
/** record area for ACCTS **/
_Packed struct rec2{
char acctn[5];
char bal[9];
char actacc[1];
} accfile;
/********************************************************************/
/********************************************************************/
/* Start of the Main Line Code. ************************************/
/********************************************************************/
/********************************************************************/
main(int argc, char **argv)
{
_RFILE *out1; /* file pointer for ATMS */
_RFILE *out2; /* file pointer for ACCTS */
_RIOFB_T *fb; /* file feedback pointer */
char record[16]; /* record buffer */
_FEEDBACK fc; /* feedback for message handler */
_HDLR_ENTRY hdlr = main_handler;
/********************************/
/* active exception handler */
/********************************/
CEEHDLR(&hdlr, NULL, &fc);;
/********************************/
/* ensure exception handler OK */
/********************************/
if (fc.MsgNo != CEE0000)
{
printf("Failed to register exception handler.\n");
exit(99);
}
/* set pointer to the input parameter */
hstruct = (Qdb_Trigger_Buffer_t *)argv[1];
datapt = (char *) hstruct;
/* Copy old and new record from the input parameter */
if ((strncmp(hstruct ->trigger_event,"2",1)== 0)|| /* delete event */
(strncmp(hstruct -> trigger_event,"3",1)== 0)) /* update event */
{ obufoff = hstruct ->old_record_offset;
memcpy(&oldbuf,datapt+obufoff,; hstruct->old_record_len);
}
if ((strncmp(hstruct -> trigger_event,"1",1)== 0) || /* insert event */
(strncmp(hstruct -> trigger_event,"3",1)== 0)) /* update event */
{ nbufoff = hstruct ->new_record_offset;
memcpy(&newbuf,datapt+nbufoff,; hstruct->new_record_len);
}
/*****************************************************/
/* Open ATM and ACCTS files */
/* */
/* Check the application's commit lock level. If it */
/* runs under commitment control, then open both */
/* files with commitment control. Otherwise, open */
/* both files without commitment control. */
/*****************************************************/
if(strcmp(hstruct->commit_lock_level,"0") == 0) /* no commit */
{
if ((out1=_Ropen("APPLIB/ATMS","rr+")) == NULL)
{
printf("Error opening ATM file");
exit(1);
}
if ((out2=_Ropen("APPLIB/ACCTS","rr+")) == NULL)
{
printf("Error opening ACCTS file");
exit(1);
}
}
else /* with commitment control */
{
if ((out1=_Ropen("APPLIB/ATMS","rr+,commit=Y")) == NULL)
{
printf("Error opening ATMS file");
exit(1);
}
if ((out2=_Ropen("APPLIB/ACCTS","rr+,commit=Y")) == NULL)
{
printf("Error opening ACCTS file");
exit(1);
}
}
/* Delete the record based on the input parameter */
fb =_Rlocate(out1,&oldbuf.atmid,KEYLEN,__DFT);
if (fb->num_bytes != 1)
{
printf("record not found in ATMS\n");
_Rclose(out1);
exit(1);
}
_Rdelete(out1); /* delete record from ATMS */
_Rclose(out1);
fb =_Rlocate(out2,&oldbuf.acctid,KEYLEN,__DFT);
if (fb->num_bytes != 1)
{
printf("record not found in ACCOUNTS\n");
_Rclose(out2);
exit(1);
}
_Rdelete(out2); /* delete record from ACCOUNTS */
_Rclose(out2);
} /* end of main */
After the deletion by the application, the ATMTRANS file contains the following data:
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/******************************************************************/
/* INCLUDE NAME : MSGHANDLER */
/* */
/* DESCRIPTION : Message handler to signal an exception message*/
/* to the caller of this trigger program. */
/* */
/* Note: This message handler is a user defined routine. */
/* */
/******************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <recio.h>
#include <leawi.h>
#pragma linkage (QMHSNDPM, OS)
void QMHSNDPM(char *, /* Message identifier */
void *, /* Qualified message file name */
void *, /* Message data or text */
int, /* Length of message data or text */
char *, /* Message type */
char *, /* Call message queue */
int, /* Call stack counter */
void *, /* Message key */
void *, /* Error code */
...); /* Optionals:
length of call message queue
name
Call stack entry qualification
display external messages
screen wait time */
/*********************************************************************/
/******** This is the start of the exception handler function. */
/*********************************************************************/
void main_handler(_FEEDBACK *cond, _POINTER *token, _INT4 *rc,
_FEEDBACK *new)
{
/****************************************/
/* Initialize variables for call to */
/* QMHSNDPM. */
/* User defines any message ID and */
/* message file for the following data */
/****************************************/
char message_id[7] = "TRG9999";
char message_file[20] = "MSGF LIB1 ";
char message_data[50] = "Trigger error ";
int message_len = 30;
char message_type[10] = "*ESCAPE ";
char message_q[10] = "_C_pep ";
int pgm_stack_cnt = 1;
char message_key[4];
/****************************************/
/* Declare error code structure for */
/* QMHSNDPM. */
/****************************************/
struct error_code {
int bytes_provided;
int bytes_available;
char message_id[7];
} error_code;
error_code.bytes_provided = 15;
/****************************************/
/* Set the error handler to resume and */
/* mark the last escape message as */
/* handled. */
/****************************************/
*rc = CEE_HDLR_RESUME;
/****************************************/
/* Send my own *ESCAPE message. */
/****************************************/
QMHSNDPM(message_id,
&message_file,
&message_data,
message_len,
message_type,
message_q,
pgm_stack_cnt,
&message_key,
&error_code );
/****************************************/
/* Check that the call to QMHSNDPM */
/* finished correctly. */
/****************************************/
if (error_code.bytes_available != 0)
{
printf("Error in QMHOVPM : %s\n", error_code.message_id);
}
}
/****************************************************************/
/* INCLUDE NAME : TRGBUF */
/* */
/* DESCRIPTION : The input trigger buffer structure for the */
/* user's trigger program. */
/* */
/* LANGUAGE : ILE C */
/* */
/****************************************************************/
/****************************************************************/
/* Note: The following type definition only defines the fixed */
/* portion of the format. The data area of the original */
/* record, null byte map of the original record, the */
/* new record, and the null byte map of the new record */
/* is varying length and immediately follows what is */
/* defined here. */
/****************************************************************/
typedef _Packed struct Qdb_Trigger_Buffer {
char file_name[10];
char library_name[10];
char member_name[10];
char trigger_event[1];
char trigger_time[1];
char commit_lock_level[1];
char reserved_1[3];
int data_area_ccsid;
char reserved_2]8];
int old_record_offset;
int old_record_len;
int old_record_null_byte_map;
int old_record_null_byte_map_len;
int new_record_offset;
int new_record_len;
int new_record_null_byte_map;
int new_record_null_byte_map_len;
} Qdb_Trigger_Buffer_t;