cmph(1) minimum perfect hashing tool


cmph [-v] [-h] [-V] [-k nkeys] [-f hash_function] [-g [-c value][-s seed] ] [-a algorithm] [-M memory_in_MB] [-b BRZ_parameter] [-d tmp_dir] [-m file.mph] keysfile


Command line tool to generate and query minimal perfect hash functions.

Please refer to for full documentation.

Print an help message
This value determines: the number of vertices in the graph for the algorithms BMZ and CHM; the number of bits per key required in the FCH algorithm
Algorithm. Valid values are: bmz, bmz8, chm, brz, fch
hash function (may be used multiple times). valid values are: djb2, fnv, jenkins, sdbm
Print version number and exit
Increase verbosity (may be used multiple times)
Number of keys
Generation mode
Random seed
Minimum perfect hash function file
Main memory availability (in MB)
Temporary directory used in brz algorithm
Parameter of BRZ algorithm to make the maximal number of keys in a bucket lower than 256
Line separated file with keys


$ # Using the default algorithm (chm) for constructing a mphf
$ # for keys in file keys_file. Lines in keys_file _must_ be unique.
$ ./cmph -v -g keys_file
$ # Query id of keys in the file keys_query
$ ./cmph -v -m keys_file.mph keys_query


This manual page was written by Enrico Tassi <[email protected]>, for the Debian project (but may be used by others).