Apache HTTP Server Version 2.2

httxt2dbm is used to generate dbm files from text input, for
    use in RewriteMap with
    the dbm map type.
    
httxt2dbm
    [ -v ]
    [ -f DBM_TYPE ]
    -i SOURCE_TXT
    -o OUTPUT_DBM
    
-v-f DBM_TYPEGDBM for GDBM files,
    SDBM for SDBM files,
    DB for berkeley DB files,
    NDBM for NDBM files,
    default for the default DBM type.
    -i SOURCE_TXTkey value.
    See the documentation for RewriteMap for
    further details of this file's format and meaning.
    -o  OUTPUT_DBM
      httxt2dbm -i rewritemap.txt -o rewritemap.dbm
      httxt2dbm -f SDBM -i rewritemap.txt -o rewritemap.dbm