borg/docs/man/borg-patterns.1

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.TH "BORG-PATTERNS" 1 "2022-10-02" "" "borg backup tool"
.SH NAME
borg-patterns \- Details regarding patterns
.SH DESCRIPTION
.sp
When specifying one or more file paths in a Borg command that supports
patterns for the respective option or argument, you can apply the
patterns described here to include only desired files and/or exclude
unwanted ones. Patterns can be used
.INDENT 0.0
.IP \(bu 2
for \fB\-\-exclude\fP option,
.IP \(bu 2
in the file given with \fB\-\-exclude\-from\fP option,
.IP \(bu 2
for \fB\-\-pattern\fP option,
.IP \(bu 2
in the file given with \fB\-\-patterns\-from\fP option and
.IP \(bu 2
for \fBPATH\fP arguments that explicitly support them.
.UNINDENT
.sp
Borg always stores all file paths normalized and relative to the
current recursion root. The recursion root is also named \fBPATH\fP in
Borg commands like \fIborg create\fP that do a file discovery, so do not
confuse the root with the \fBPATH\fP argument of e.g. \fIborg extract\fP\&.
.sp
Starting with Borg 1.2, paths that are matched against patterns always
appear relative. If you give \fB/absolute/\fP as root, the paths going
into the matcher will look relative like \fBabsolute/.../file.ext\fP\&.
If you give \fB\&../some/path\fP as root, the paths will look like
\fBsome/path/.../file.ext\fP\&.
.sp
File patterns support five different styles. If followed by a colon \(aq:\(aq,
the first two characters of a pattern are used as a style selector.
Explicit style selection is necessary if a non\-default style is desired
or when the desired pattern starts with two alphanumeric characters
followed by a colon (i.e. \fBaa:something/*\fP).
.INDENT 0.0
.TP
.B \fI\%Fnmatch\fP, selector \fBfm:\fP
This is the default style for \fB\-\-exclude\fP and \fB\-\-exclude\-from\fP\&.
These patterns use a variant of shell pattern syntax, with \(aq*\(aq matching
any number of characters, \(aq?\(aq matching any single character, \(aq[...]\(aq
matching any single character specified, including ranges, and \(aq[!...]\(aq
matching any character not specified. For the purpose of these patterns,
the path separator (backslash for Windows and \(aq/\(aq on other systems) is not
treated specially. Wrap meta\-characters in brackets for a literal
match (i.e. \fB[?]\fP to match the literal character \(aq?\(aq). For a path
to match a pattern, 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 \(aq*\(aq is appended before matching is attempted. A leading
path separator is always removed.
.TP
.B Shell\-style patterns, selector \fBsh:\fP
This is the default style for \fB\-\-pattern\fP and \fB\-\-patterns\-from\fP\&.
Like fnmatch patterns these are similar to shell patterns. The difference
is that the pattern may include \fB**/\fP for matching zero or more directory
levels, \fB*\fP for matching zero or more arbitrary characters with the
exception of any path separator. A leading path separator is always removed.
.TP
.B \fI\%Regular expressions\fP, selector \fBre:\fP
Unlike shell patterns, regular expressions are not required to match the full
path and any substring match is sufficient. It is strongly recommended to
anchor patterns to the start (\(aq^\(aq), to the end (\(aq$\(aq) or both. Path
separators (backslash for Windows and \(aq/\(aq on other systems) in paths are
always normalized to a forward slash \(aq/\(aq before applying a pattern.
.TP
.B Path prefix, selector \fBpp:\fP
This pattern style is useful to match whole sub\-directories. The pattern
\fBpp:root/somedir\fP matches \fBroot/somedir\fP and everything therein.
A leading path separator is always removed.
.TP
.B Path full\-match, selector \fBpf:\fP
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. \fBpf:root/file.ext\fP
matches \fBroot/file.ext\fP only. A leading path separator is always
removed.
.sp
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 included
(if the directory recursion encounters it).
Other include/exclude patterns that would normally match will be ignored.
Same logic applies for exclude.
.UNINDENT
.sp
\fBNOTE:\fP
.INDENT 0.0
.INDENT 3.5
\fBre:\fP, \fBsh:\fP and \fBfm:\fP 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 supply \fBre:\fP patterns. Further, ensure that \fBsh:\fP and
\fBfm:\fP patterns only contain a handful of wildcards at most.
.UNINDENT
.UNINDENT
.sp
Exclusions can be passed via the command line option \fB\-\-exclude\fP\&. When used
from within a shell, the patterns should be quoted to protect them from
expansion.
.sp
The \fB\-\-exclude\-from\fP option permits loading exclusion patterns from a text
file with one pattern per line. Lines empty or starting with the hash sign
\(aq#\(aq 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.
.sp
To test your exclusion patterns without performing an actual backup you can
run \fBborg create \-\-list \-\-dry\-run ...\fP\&.
.sp
Examples:
.INDENT 0.0
.INDENT 3.5
.sp
.nf
.ft C
# Exclude \(aq/home/user/file.o\(aq but not \(aq/home/user/file.odt\(aq:
$ borg create \-e \(aq*.o\(aq archive /

# Exclude \(aq/home/user/junk\(aq and \(aq/home/user/subdir/junk\(aq but
# not \(aq/home/user/importantjunk\(aq or \(aq/etc/junk\(aq:
$ borg create \-e \(aqhome/*/junk\(aq archive /

# Exclude the contents of \(aq/home/user/cache\(aq but not the directory itself:
$ borg create \-e home/user/cache/ archive /

# The file \(aq/home/user/cache/important\(aq is *not* backed up:
$ borg create \-e home/user/cache/ archive / /home/user/cache/important

# The contents of directories in \(aq/home\(aq are not backed up when their name
# ends in \(aq.tmp\(aq
$ borg create \-\-exclude \(aqre:^home/[^/]+\e.tmp/\(aq archive /

# Load exclusions from file
$ cat >exclude.txt <<EOF
# Comment line
home/*/junk
*.tmp
fm:aa:something/*
re:^home/[^/]+\e.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 archive /
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
A more general and easier to use way to define filename matching patterns
exists with the \fB\-\-pattern\fP and \fB\-\-patterns\-from\fP options. Using
these, you may specify the backup roots, default pattern styles and
patterns for inclusion and exclusion.
.INDENT 0.0
.TP
.B Root path prefix \fBR\fP
A recursion root path starts with the prefix \fBR\fP, followed by a path
(a plain path, not a file pattern). Use this prefix to have the root
paths in the patterns file rather than as command line arguments.
.TP
.B Pattern style prefix \fBP\fP
To change the default pattern style, use the \fBP\fP prefix, followed by
the pattern style abbreviation (\fBfm\fP, \fBpf\fP, \fBpp\fP, \fBre\fP, \fBsh\fP).
All patterns following this line will use this style until another style
is specified.
.TP
.B Exclude pattern prefix \fB\-\fP
Use the prefix \fB\-\fP, followed by a pattern, to define an exclusion.
This has the same effect as the \fB\-\-exclude\fP option.
.TP
.B Exclude no\-recurse pattern prefix \fB!\fP
Use the prefix \fB!\fP, followed by a pattern, to define an exclusion
that does not recurse into subdirectories. This saves time, but
prevents include patterns to match any files in subdirectories.
.TP
.B Include pattern prefix \fB+\fP
Use the prefix \fB+\fP, followed by a pattern, to define inclusions.
This is useful to include paths that are covered in an exclude
pattern and would otherwise not be backed up.
.UNINDENT
.sp
The first matching pattern is used, so if an include pattern matches
before an exclude pattern, the file is backed up. Note that a no\-recurse
exclude stops examination of subdirectories so that potential includes
will not match \- use normal excludes for such use cases.
.sp
\fBTip: You can easily test your patterns with \-\-dry\-run and  \-\-list\fP:
.INDENT 0.0
.INDENT 3.5
.sp
.nf
.ft C
$ borg create \-\-dry\-run \-\-list \-\-patterns\-from patterns.txt archive
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
This will list the considered files one per line, prefixed with a
character that indicates the action (e.g. \(aqx\(aq for excluding, see
\fBItem flags\fP in \fIborg create\fP usage docs).
.sp
\fBNOTE:\fP
.INDENT 0.0
.INDENT 3.5
It\(aqs possible that a sub\-directory/file is matched while parent
directories are not. In that case, parent directories are not backed
up and thus their user, group, permission, etc. cannot be restored.
.UNINDENT
.UNINDENT
.sp
Patterns (\fB\-\-pattern\fP) and excludes (\fB\-\-exclude\fP) from the command line are
considered first (in the order of appearance). Then patterns from \fB\-\-patterns\-from\fP
are added. Exclusion patterns from \fB\-\-exclude\-from\fP files are appended last.
.sp
Examples:
.INDENT 0.0
.INDENT 3.5
.sp
.nf
.ft C
# 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 archive pics

# backup only JPG/JPEG files (case insensitive) in all home directories:
borg create \-\-pattern \(aq+ re:\e.jpe?g(?i)$\(aq archive /home

# backup homes, but exclude big downloads (like .ISO files) or hidden files:
borg create \-\-exclude \(aqre:\e.iso(?i)$\(aq \-\-exclude \(aqsh:home/**/.*\(aq archive /home

# use a file with patterns (recursion root \(aq/\(aq via command line):
borg create \-\-patterns\-from patterns.lst archive /
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
The patterns.lst file could look like that:
.INDENT 0.0
.INDENT 3.5
.sp
.nf
.ft C
# \(dqsh:\(dq pattern style is the default
# exclude caches
\- home/*/.cache
# include susans home
+ home/susan
# also back up this exact file
+ pf:home/bobby/specialfile.txt
# don\(aqt backup the other home directories
\- home/*
# don\(aqt even look in /dev, /proc, /run, /sys, /tmp (note: would exclude files like /device, too)
! re:^(dev|proc|run|sys|tmp)
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
You can specify recursion roots either on the command line or in a patternfile:
.INDENT 0.0
.INDENT 3.5
.sp
.nf
.ft C
# these two commands do the same thing
borg create \-\-exclude home/bobby/junk archive /home/bobby /home/susan
borg create \-\-patterns\-from patternfile.lst archive
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
patternfile.lst:
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.INDENT 3.5
.sp
.nf
.ft C
# 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
.ft P
.fi
.UNINDENT
.UNINDENT
.sp
This allows you to share the same patterns between multiple repositories
without needing to specify them on the command line.
.SH AUTHOR
The Borg Collective
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