_Rrollbck() — Roll Back Commitment Control Changes

Format

#include <recio.h>

int _Rrollbck(void);

Language Level

ILE C Extension

Threadsafe

No

Description

The _Rrollbck() function reestablishes the last commitment boundary as the current commitment boundary. All changes that are made to the files under commitment control in the job, are reversed. All locked records are released. Any file that is open under commitment control in the job will be affected. You must specify the keyword parameter commit=y when the file is opened to be under commitment control. A commitment control environment must have been set up prior to this.

The _Rrollbck() function is valid for database and DDM files.

Return Value

The _Rrollbck() function returns 1 if the operation is successful or zero if the operation is unsuccessful. The value of errno may be set to EIOERROR (a non-recoverable I/O error occurred) or EIORECERR (a recoverable I/O error occurred). See Table 1 and Table 1 for errno settings.

Example

#include <stdio.h>
#include <recio.h>
#include <stdlib.h>
#include <string.h>
 
int main(void)
{
  char       buf[40];
  int        rc = 1;
  _RFILE     *purf;
  _RFILE     *dailyf;
 
  /* Open purchase display file and daily transaction file          */
  if ( ( purf = _Ropen ( "MYLIB/T1677RD3", "ar+,indicators=y" )) == NULL )
  {
      printf ( "Display file did not open.\n" );
      exit ( 1 );
  }
 
  if ( ( dailyf = _Ropen ( "MYLIB/T1677RDA", "wr,commit=y") ) == NULL )
  {
      printf ( "Daily transaction file did not open.\n" );
      exit ( 2 );
  }
 
  /* Select purchase record format */
  _Rformat ( purf, "PURCHASE" );
 
  /* Invite user to enter a purchase transaction.                   */
  /* The _Rwrite function writes the purchase display.              */
  _Rwrite ( purf, "", 0 );
  _Rreadn ( purf, buf, sizeof(buf), __DFT );
 
  /* Update daily transaction file                                  */
  rc = (( _Rwrite ( dailyf, buf, sizeof(buf) ))->num_bytes );
 
  /* If the databases were updated, then commit the transaction.    */
  /* Otherwise, rollback the transaction and indicate to the        */
  /* user that an error has occurred and end the application.       */
  if ( rc )
    {
        _Rcommit ( "Transaction complete" );
    }
  else
    {
        _Rrollbck ( );
        _Rformat ( purf, "ERROR" );
    }
 
  _Rclose ( purf );
  _Rclose ( dailyf );
}

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