DB_ENV->log_file()
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## DB_ENV->log_file()

    #include <db.h>

    int
    DB_ENV->log_file(DB_ENV *env,
        const DB_LSN *lsn, char *namep, size_t len);

The `DB_ENV->log_file()` method maps `DB_LSN` structures to filenames, returning the name of the file containing the record named by lsn.

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

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

### Parameters

#### lsn

The lsn parameter is the `DB_LSN` structure 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, `DB_ENV->log_file()` will fail. (Log filenames are always 14 characters long.)

### Errors

The `DB_ENV->log_file()` method may fail and 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

DB_ENV, DB_LOGC, DB_LSN

### See Also

Logging Subsystem and Related Methods

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