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CMPH

NAME

cmph − minimum perfect hashing tool

SYNOPSIS

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

DESCRIPTION

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

Please refer to http://cmph.sf.net for full documentation.

−h

Print an help message

−c

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

−a

Algorithm. Valid values are: bmz, bmz8, chm, brz, fch

−f

hash function (may be used multiple times). valid values are: djb2, fnv, jenkins, sdbm

−V

Print version number and exit

−v

Increase verbosity (may be used multiple times)

−k

Number of keys

−g

Generation mode

−s

Random seed

−m

Minimum perfect hash function file

−M

Main memory availability (in MB)

−d

Temporary directory used in brz algorithm

−b

Parameter of BRZ algorithm to make the maximal number of keys in a bucket lower than 256

keysfile

Line separated file with keys

EXAMPLE

$ # 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

AUTHOR

This manual page was written by Enrico Tassi <gareuselesinge AT users DOT sourceforge DOT net>, for the Debian project (but may be used by others).

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