BORG-PATTERNS(1) borg backup tool BORG-PATTERNS(1)
NAME
borg-patterns - Details regarding patterns
DESCRIPTION
The path/filenames used as input for the pattern matching start from
the currently active recursion root. You usually give the recursion
root(s) when invoking borg and these can be either relative or absolute
paths.
If you give /absolute/ as root, the paths going into the matcher will
look relative like absolute/.../file.ext, because file paths in Borg
archives are always stored normalized and relative. This means that
e.g. borg create /path/to/repo ../some/path will store all files as
some/path/.../file.ext and borg create /path/to/repo /home/user will
store all files as home/user/.../file.ext.
A directory exclusion pattern can end either with or without a slash
('/'). If it ends with a slash, such as some/path/, the directory will
be included but not its content. If it does not end with a slash, such
as some/path, both the directory and content will be excluded.
File patterns support these styles: fnmatch, shell, regular expres-
sions, path prefixes and path full-matches. By default, fnmatch is used
for --exclude patterns and shell-style is used for the --pattern op-
tion. For commands that support patterns in their PATH argument like
(borg list), the default pattern is path prefix.
Starting with Borg 1.2, discovered fs paths are normalised, have lead-
ing slashes removed and then are matched against your patterns. Note:
You need to review your include / exclude patterns and make sure they
do not expect leading slashes. Borg can only deal with this for some
very simple patterns by removing leading slashes there also.
If followed by a colon (':') the first two characters of a pattern are
used as a style selector. Explicit style selection is necessary when a
non-default style is desired or when the desired pattern starts with
two alphanumeric characters followed by a colon (i.e. aa:something/*).
Fnmatch, selector fm:
This is the default style for --exclude and --exclude-from.
These patterns use a variant of shell pattern syntax, with '*'
matching any number of characters, '?' matching any single char-
acter, '[...]' matching any single character specified, includ-
ing ranges, and '[!...]' matching any character not specified.
For the purpose of these patterns, the path separator (backslash
for Windows and '/' on other systems) is not treated specially.
Wrap meta-characters in brackets for a literal match (i.e. [?]
to match the literal character ?). For a path to match a pat-
tern, the full path must match, or it must match from the start
of the full path to just before a path separator. Except for the
root path, paths will never end in the path separator when
matching is attempted. Thus, if a given pattern ends in a path
separator, a '*' is appended before matching is attempted. A
leading path separator is always removed.
Shell-style patterns, selector sh:
This is the default style for --pattern and --patterns-from.
Like fnmatch patterns these are similar to shell patterns. The
difference is that the pattern may include **/ for matching zero
or more directory levels, * for matching zero or more arbitrary
characters with the exception of any path separator. A leading
path separator is always removed.
Regular expressions, selector re:
Regular expressions similar to those found in Perl are sup-
ported. Unlike shell patterns regular expressions are not re-
quired to match the full path and any substring match is suffi-
cient. It is strongly recommended to anchor patterns to the
start ('^'), to the end ('$') or both. Path separators (back-
slash for Windows and '/' on other systems) in paths are always
normalized to a forward slash ('/') before applying a pattern.
The regular expression syntax is described in the Python docu-
mentation for the re module.
Path prefix, selector pp:
This pattern style is useful to match whole sub-directories. The
pattern pp:root/somedir matches root/somedir and everything
therein. A leading path separator is always removed.
Path full-match, selector pf:
This pattern style is (only) useful to match full paths. This
is kind of a pseudo pattern as it can not have any variable or
unspecified parts - the full path must be given.
pf:root/file.ext matches root/file.ext only. A leading path sep-
arator is always removed.
Implementation note: this is implemented via very time-efficient
O(1) hashtable lookups (this means you can have huge amounts of
such patterns without impacting performance much). Due to that,
this kind of pattern does not respect any context or order. If
you use such a pattern to include a file, it will always be in-
cluded (if the directory recursion encounters it). Other in-
clude/exclude patterns that would normally match will be ig-
nored. Same logic applies for exclude.
NOTE:
re:, sh: and fm: patterns are all implemented on top of the Python
SRE engine. It is very easy to formulate patterns for each of these
types which requires an inordinate amount of time to match paths. If
untrusted users are able to supply patterns, ensure they cannot sup-
ply re: patterns. Further, ensure that sh: and fm: patterns only
contain a handful of wildcards at most.
Exclusions can be passed via the command line option --exclude. When
used from within a shell, the patterns should be quoted to protect them
from expansion.
The --exclude-from option permits loading exclusion patterns from a
text file with one pattern per line. Lines empty or starting with the
number sign ('#') after removing whitespace on both ends are ignored.
The optional style selector prefix is also supported for patterns
loaded from a file. Due to whitespace removal, paths with whitespace at
the beginning or end can only be excluded using regular expressions.
To test your exclusion patterns without performing an actual backup you
can run borg create --list --dry-run ....
Examples:
# Exclude '/home/user/file.o' but not '/home/user/file.odt':
$ borg create -e '*.o' backup /
# Exclude '/home/user/junk' and '/home/user/subdir/junk' but
# not '/home/user/importantjunk' or '/etc/junk':
$ borg create -e 'home/*/junk' backup /
# Exclude the contents of '/home/user/cache' but not the directory itself:
$ borg create -e home/user/cache/ backup /
# The file '/home/user/cache/important' is *not* backed up:
$ borg create -e home/user/cache/ backup / /home/user/cache/important
# The contents of directories in '/home' are not backed up when their name
# ends in '.tmp'
$ borg create --exclude 're:^home/[^/]+\.tmp/' backup /
# Load exclusions from file
$ cat >exclude.txt <<EOF
# Comment line
home/*/junk
*.tmp
fm:aa:something/*
re:^home/[^/]+\.tmp/
sh:home/*/.thumbnails
# Example with spaces, no need to escape as it is processed by borg
some file with spaces.txt
EOF
$ borg create --exclude-from exclude.txt backup /
A more general and easier to use way to define filename matching pat-
terns exists with the --pattern and --patterns-from options. Using
these, you may specify the backup roots (starting points) and patterns
for inclusion/exclusion. A root path starts with the prefix R, fol-
lowed by a path (a plain path, not a file pattern). An include rule
starts with the prefix +, an exclude rule starts with the prefix -, an
exclude-norecurse rule starts with !, all followed by a pattern.
NOTE:
Via --pattern or --patterns-from you can define BOTH inclusion and
exclusion of files using pattern prefixes + and -. With --exclude
and --exclude-from ONLY excludes are defined.
Inclusion patterns are useful to include paths that are contained in an
excluded path. The first matching pattern is used so if an include pat-
tern matches before an exclude pattern, the file is backed up. If an
exclude-norecurse pattern matches a directory, it won't recurse into it
and won't discover any potential matches for include rules below that
directory.
NOTE:
It's possible that a sub-directory/file is matched while parent di-
rectories are not. In that case, parent directories are not backed
up thus their user, group, permission, etc. can not be restored.
Note that the default pattern style for --pattern and --patterns-from
is shell style (sh:), so those patterns behave similar to rsync in-
clude/exclude patterns. The pattern style can be set via the P prefix.
Patterns (--pattern) and excludes (--exclude) from the command line are
considered first (in the order of appearance). Then patterns from
--patterns-from are added. Exclusion patterns from --exclude-from files
are appended last.
Examples:
# backup pics, but not the ones from 2018, except the good ones:
# note: using = is essential to avoid cmdline argument parsing issues.
borg create --pattern=+pics/2018/good --pattern=-pics/2018 repo::arch pics
# use a file with patterns:
borg create --patterns-from patterns.lst repo::arch
The patterns.lst file could look like that:
# "sh:" pattern style is the default, so the following line is not needed:
P sh
R /
# can be rebuild
- home/*/.cache
# they're downloads for a reason
- home/*/Downloads
# susan is a nice person
# include susans home
+ home/susan
# also back up this exact file
+ pf:home/bobby/specialfile.txt
# don't backup the other home directories
- home/*
# don't even look in /proc
! proc
You can specify recursion roots either on the command line or in a pat-
ternfile:
# these two commands do the same thing
borg create --exclude home/bobby/junk repo::arch /home/bobby /home/susan
borg create --patterns-from patternfile.lst repo::arch
The patternfile:
# note that excludes use fm: by default and patternfiles use sh: by default.
# therefore, we need to specify fm: to have the same exact behavior.
P fm
R /home/bobby
R /home/susan
- home/bobby/junk
This allows you to share the same patterns between multiple reposito-
ries without needing to specify them on the command line.
AUTHOR
The Borg Collective
2023-03-22 BORG-PATTERNS(1)
Generated by dwww version 1.15 on Sat Jun 29 01:57:14 CEST 2024.