bup-bloom(1) Bup 0.33.10+
Author: Brandon Low lostlogic@lostlogicx.com
Date: 2026-01-28

# NAME

bup-bloom - generates, regenerates, updates bloom filters

# SYNOPSIS

bup bloom [-d dir] [-o outfile] [-k hashes] [-c idxfile] [-f] [--ruin]

# DESCRIPTION

`bup bloom` builds a bloom filter file for a bup repository. If one already exists, it checks the filter and updates or regenerates it as needed.

# OPTIONS

--ruin
  destroy bloom filters by setting the whole bitmask to zeros. you really want to know what you are doing if run this and you want to delete the resulting bloom when you are done with it.
-f, --force
  don’t update the existing bloom file; generate a new one from scratch.
-d, --dir=directory
  the directory, containing `.idx` files, to process. Defaults to $BUP_DIR/objects/pack
-o, --outfile=outfile
  the file to write the bloom filter to. defaults to $dir/bup.bloom
-k, --hashes=hashes
  number of hash functions to use only 4 and 5 are valid. defaults to 5 for repositories < 2 TiB, or 4 otherwise. See comments in git.py for more on this value.
-c, --check=idxfile
  checks the bloom file (counterintuitively outfile) against the specified `.idx` file, first checks that the bloom filter is claiming to contain the `.idx`, then checks that it does actually contain all of the objects in the `.idx`. Does not write anything and ignores the `-k` option.

# BUP

Part of the `bup`(1) suite.