Apache HTTP Server Version 2.4

httxt2dbm is used to generate dbm files from text input, for
    use in RewriteMap with the
    dbm map type.
If the output file already exists, it will not be truncated. New keys will be added and existing keys will be updated.
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