CMPH(1)

✨ CMPH(1) ✨

okay bestie, gather round, because today we're learning about cmph, the minimum perfect hashing tool 💖 (that's the manual name btw, CMPH(1), section 1, we love her)

🌸 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 💅

It's a command line tool that generates and queries minimal perfect hash functions. That's the whole vibe. 🦋

For the full documentation, please refer to http://cmph.sf.net — the source site, no cap. ✨

• -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

bestie the lines in keys_file MUST be unique, that's not a suggestion, that's the law 😭

💜 AUTHOR 💜

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

okay that's the whole thing, go forth and hash perfectly 💖✨ this was cmph version 0.6, dated October 2007, and honestly? iconic. periodt. 👑🌸