DB_ENV->log_put()
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## DB_ENV->log_put()

    #include <db.h>

    int
    DB_ENV->log_put(DB_ENV *env,
        DB_LSN *lsn, const DBT *data, u_int32_t flags);

The `DB_ENV->log_put()` method appends records to the log. The DB_LSN of the put record is returned in the lsn parameter.

The `DB_ENV->log_put()` method returns a non-zero error value on failure and 0 on success.

### Parameters

#### data

The data parameter is the record to write to the log.

The caller is responsible for providing any necessary structure to data. (For example, in a write-ahead logging protocol, the application must understand what part of data is an operation code, what part is redo information, and what part is undo information. In addition, most transaction managers will store in data the DB_LSN of the previous log record for the same transaction, to support chaining back through the transaction's log records during undo.)

#### flags

The flags parameter must be set to 0 or the following value:

- `DB_FLUSH`

  The log is forced to disk after this record is written, guaranteeing that all records with DB_LSN values less than or equal to the one being "put" are on disk before `DB_ENV->log_put()` returns.

#### lsn

The lsn parameter references memory into which the DB_LSN of the put record is copied.

### Errors

The `DB_ENV->log_put()` method may fail and return one of the following non-zero errors:

#### EINVAL

If the record to be logged is larger than the maximum log record; or if an invalid flag value or parameter was specified.

### Class

DB_ENV, DB_LOGC, DB_LSN

### See Also

Logging Subsystem and Related Methods

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