### DbEnv::log_file

`

###

    #include <db_cxx.h>

    int
    DbEnv::log_file(const DbLsn *lsn, char *namep, size_t len);

### Description: DbEnv::log_file

The DbEnv::log_file method maps DbLsn objects to filenames, returning the name of the file containing the record named by lsn.

This mapping of DbLsn objects to files is needed for database administration. For example, a transaction manager typically records the earliest DbLsn needed for restart, and the database administrator may want to archive log files to tape when they contain only DbLsn entries before the earliest one needed for restart.

The DbEnv::log_file method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success.

### Parameters

lsn
  The lsn parameter is the DbLsn object for which a filename is wanted.
namep
  The namep parameter references memory into which the name of the file containing the record named by lsn is copied.
len
  The len parameter is the length of the namep buffer in bytes. If namep is too short to hold the filename, DbEnv::log_file will fail. (Log filenames are normally quite short, on the order of 10 characters.)

### Errors

The DbEnv::log_file method may fail and throw DbException, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

EINVAL
  If supplied buffer was too small to hold the log filename; or if an invalid flag value or parameter was specified.

### Class

DbEnv, DbLogc, DbLsn

### See Also

Logging Subsystem and Related Methods`

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