SQLite

/*
** This is the callback routine that the shell
** invokes for each row of a query result.
*/
static int shell_callback(void *pArg, int nArg, char **azArg, char **azCol, int *aiType){
  int i;
  struct callback_data *p = (struct callback_data*)pArg;

  if( p->echoOn && p->cnt==0  && p->pStmt){
    printf("%s\n", sqlite3_sql(p->pStmt));
  }

  switch( p->mode ){
    case MODE_Line: {
      int w = 5;
      if( azArg==0 ) break;
      for(i=0; i<nArg; i++){
        int len = strlen30(azCol[i] ? azCol[i] : "");
        if( len>w ) w = len;

      for(i=0; i<nArg; i++){
        output_csv(p, azArg[i], i<nArg-1);
      }
      fprintf(p->out,"\n");
      break;
    }
    case MODE_Insert: {
      p->cnt++;
      if( azArg==0 ) break;
      fprintf(p->out,"INSERT INTO %s VALUES(",p->zDestTable);
      for(i=0; i<nArg; i++){
        char *zSep = i>0 ? ",": "";
        if( (azArg[i]==0) || (aiType && aiType[i]==SQLITE_NULL) ){
          fprintf(p->out,"%sNULL",zSep);
        }else if( aiType && aiType[i]==SQLITE_TEXT ){

  const char *zSql,                           /* SQL to be evaluated */
  int (*xCallback)(void*,int,char**,char**,int*),   /* Callback function */
                                              /* (not the same as sqlite3_exec) */
  struct callback_data *pArg,                 /* Pointer to struct callback_data */
  char **pzErrMsg                             /* Error msg written here */
){
  sqlite3_stmt *pStmt = NULL;
  int rc = SQLITE_OK;
  int rc2;
  const char *zLeftover;      /* Tail of unprocessed SQL */

  if( pzErrMsg ){
    *pzErrMsg = NULL;
  }

  while( zSql[0] && (SQLITE_OK == rc) ){
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db);
      }
    }else{
      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( isspace(zSql[0]) ) zSql++;
        continue;
      }

      /* perform the first step.  this will tell us if we
      ** have a result set or not and how wide it is.
      */
      rc = sqlite3_step(pStmt);
      /* if we have a result set... */
      if( SQLITE_ROW == rc ){
        /* if we have a callback... */
        if( xCallback ){
          /* allocate space for col name ptr, value ptr, and type */
          int nCol = sqlite3_column_count(pStmt);
          void *pData = sqlite3_malloc(3*nCol*sizeof(const char*) + 1);
          if( !pData ){
            rc = SQLITE_NOMEM;
          }else{
            char **azCols = (char **)pData;      /* Names of result columns */
            char **azVals = &azCols[nCol];       /* Results */
            int *aiTypes = (int *)&azVals[nCol]; /* Result types */
            int i;
            assert(sizeof(int) <= sizeof(char *)); 
            /* save off ptrs to column names */
            for(i=0; i<nCol; i++){
              azCols[i] = (char *)sqlite3_column_name(pStmt, i);
            }
            /* save off the prepared statment handle and reset row count */
            if( pArg ){
              pArg->pStmt = pStmt;
              pArg->cnt = 0;
            }
            do{
              /* extract the data and data types */
              for(i=0; i<nCol; i++){
                azVals[i] = (char *)sqlite3_column_text(pStmt, i);
                aiTypes[i] = sqlite3_column_type(pStmt, i);
                if( !azVals[i] && (aiTypes[i]!=SQLITE_NULL) ){
                  rc = SQLITE_NOMEM;
                  break; /* from for */
                }
              } /* end for */

              /* if data and types extracted successfully... */
              if( SQLITE_ROW == rc ){ 
                /* call the supplied callback with the result row data */
                if( xCallback(pArg, nCol, azVals, azCols, aiTypes) ){
                  rc = SQLITE_ABORT;
                }else{
                  rc = sqlite3_step(pStmt);
                }
              }
            } while( SQLITE_ROW == rc );
            sqlite3_free(pData);
            if( pArg ){
              pArg->pStmt = NULL;
            }
          }
        }else{
          do{
            rc = sqlite3_step(pStmt);
          } while( rc == SQLITE_ROW );
        }
      }

      /* if the last sqlite3_step() didn't complete successfully... */
      if( (SQLITE_OK != rc) && (SQLITE_DONE != rc) ){ 
        if( pzErrMsg ){
          *pzErrMsg = save_err_msg(db);
        }
      }else{
        rc = SQLITE_OK;
      }

      rc2 = sqlite3_finalize(pStmt);
      /* if the last sqlite3_finalize() didn't complete successfully 
      ** AND we don't have a save error from sqlite3_step ... */
      if( (SQLITE_OK != rc2) && (SQLITE_OK == rc) ){
        rc = rc2;
        if( pzErrMsg ){
          *pzErrMsg = save_err_msg(db);
        }
      }

      if( SQLITE_OK == rc ){ 
        zSql = zLeftover;
        while( isspace(zSql[0]) ) zSql++;
      }
    }
  } /* end while */

  return rc;
}


/*
** This is a different callback routine used for dumping the database.

      break;  /* We have reached EOF */
    }
    if( seenInterrupt ){
      if( in!=0 ) break;
      seenInterrupt = 0;
    }
    lineno++;

    if( (zSql==0 || zSql[0]==0) && _all_whitespace(zLine) ) continue;
    if( zLine && zLine[0]=='.' && nSql==0 ){
      if( p->echoOn ) printf("%s\n", zLine);
      rc = do_meta_command(zLine, p);
      if( rc==2 ){
        break;
      }else if( rc ){
        errCnt++;
      }
      continue;