#include <db.h>
int
DB->verify(DB *db, const char *file,
    const char *database, FILE *outfile, u_int32_t flags);  
      
         The DB->verify() method verifies the integrity of all databases in
         the file specified by the file
         parameter, and optionally outputs the databases' key/data pairs to the
         file stream specified by the outfile
         parameter.
    
         The DB->verify() method does not perform any
         locking, even in Berkeley DB environments that are configured with a
         locking subsystem.  As such, it should only be used on files that are
         not being modified by another thread of control.
    
             The DB->verify() method may not be called after the 
             DB->open()  method is called.
    
         The DB  handle may not be
         accessed again after DB->verify() is called, regardless of its
         return.
    
         The DB->verify() method is the
         underlying method used by the 
         db_verify utility. See the 
         db_verify utility source code for
         an example of using DB->verify() in a
         IEEE/ANSI Std 1003.1 (POSIX) environment.
    
         The DB->verify() method will return DB_VERIFY_BAD if a database is
         corrupted.  When the DB_SALVAGE flag is specified, the DB_VERIFY_BAD
         return means that all key/data pairs in the file may not have been
         successfully output. Unless otherwise specified, the DB->verify()
         
            
                  method returns a non-zero error value on failure and 0 on success.
            
            
        
    
The database parameter is the database in file on which the database checks for btree and duplicate sort order and for hashing are to be performed. See the DB_ORDERCHKONLY flag for more information.
The database parameter must be set to NULL except when the DB_ORDERCHKONLY flag is set.
The outfile parameter is an optional file stream to which the databases' key/data pairs are written.
The flags parameter must be set to 0 or the following value:
Write the key/data pairs from all databases in the file to the file stream named in the outfile parameter. Key values are written for Btree, Hash and Queue databases, but not for Recno databases.
The output format is the same as that specified for the db_dump utility, and can be used as input for the db_load utility.
                 Because the key/data pairs are output in page order as opposed to the
                 sort order used by db_dump, using DB->verify() to
                 dump key/data pairs normally produces less than optimal loads for
                 Btree databases.
            
In addition, the following flags may be set by bitwise inclusively OR'ing them into the flags parameter:
                 Output all the key/data pairs in the
                 file that can be found. By default, DB->verify() does not assume
                 corruption.  For example, if a key/data pair on a page is marked as
                 deleted, it is not then written to the output file.  When
                 DB_AGGRESSIVE is specified, corruption is assumed, and any key/data
                 pair that can be found is written.  In this case, key/data pairs that
                 are corrupted or have been deleted may appear in the output (even if
                 the file being salvaged is in no way corrupt), and the output will
                 almost certainly require editing before being loaded into a database.
            
When using the DB_SALVAGE flag, if characters in either the key or data items are printing characters (as defined by isprint(3)), use printing characters to represent them. This flag permits users to use standard text editors and tools to modify the contents of databases or selectively remove data from salvager output.
Note: different systems may have different notions about what characters are considered printing characters, and databases dumped in this manner may be less portable to external systems.
Skip the database checks for btree and duplicate sort order and for hashing.
                 The DB->verify() method normally verifies that btree keys and
                 duplicate items are correctly sorted, and hash keys are correctly
                 hashed.  If the file being verified contains multiple databases using
                 differing sorting or hashing algorithms, some of them must necessarily
                 fail database verification because only one sort order or hash
                 function can be specified before DB->verify() is called.  To verify
                 files with multiple databases having differing sorting orders or
                 hashing functions, first perform verification of the file as a whole
                 by using the DB_NOORDERCHK flag, and then individually verify the sort
                 order and hashing function for each database in the file using the
                 DB_ORDERCHKONLY flag.
            
Perform the database checks for btree and duplicate sort order and for hashing, skipped by DB_NOORDERCHK.
                 When this flag is specified, a database parameter should also be specified,
                 indicating the database in the physical file which is to be checked. 
                 This flag is only safe to use on databases that have already
                 successfully been verified using DB->verify() with the DB_NOORDERCHK
                 flag set.
            
                         If the database was opened within a database environment, the
                         environment variable DB_HOME may be used as the path of the
                         database environment home.
                    
                            DB->verify() is affected by any database directory specified using the
                            DB_ENV->set_data_dir()
                            method, or by setting the "set_data_dir" string
                            in the environment's DB_CONFIG file.
                    
                         The DB->verify() 
            
                 method may fail and return one of the following non-zero errors:
            
            
        
                    
If the method was called after DB->open() was called; or if an invalid flag value or parameter was specified.