Ubuntu Manpage: git-annex-preferred-content - which files are wanted in a repository

Provided by: git-annex_8.20200226-1_amd64

NAME

       git-annex-preferred-content - which files are wanted in a repository

DESCRIPTION

       Each  repository  has  a  preferred  content  setting,  which  specifies  content that the
       repository wants to have present. These settings can be configured using git  annex  vicfg
       or git annex wanted.  They are used by the --auto option, by git annex sync --content, and
       by the git-annex assistant.

       While preferred content expresses a preference, it can be overridden by simply  using  git
       annex drop. On the other hand, required content settings are enforced; git annex drop will
       refuse to drop a file  if  doing  so  would  violate  its  required  content  settings.  A
       repository's  required  content  can  be  configured  using  git  annex vicfg or git annex
       required.

SYNTAX

       Preferred content expressions use a similar syntax to  the  git-annex-matching-options(1),
       without the dashes.  For example:

        exclude=archive/* and (include=*.mp3 or smallerthan=1mb)

       The  idea  is  that  you  write  an  expression  that files are matched against. If a file
       matches, the repository wants to store its content. If it doesn't, the repository wants to
       drop its content (if there are enough copies elsewhere to allow removing it).

EXPRESSIONS

include=glob / exclude=glob

Match files to include, or exclude.

While the command-line options --include=glob and --exclude=glob match files
relative to the current directory, preferred content expressions match files
relative to the top of the git repository.

For example, suppose you put files into archive directories when you're done with
them. Then you could configure your laptop to prefer to not retain those files,
like this: exclude=*/archive/*

When a subdirectory is being exported or imported to a special remote (see git-
annex-export(1)) and git-annex-import(1), these match relative to the top of the
subdirectory.

copies=number
Matches only files that git-annex believes to have the specified number of copies,
or more. Note that it does not check remotes to verify that the copies still exist.

To decide if content should be dropped, git-annex evaluates the preferred content
expression under the assumption that the content has *already* been dropped. If the
content would not be wanted then, the drop can be done. So, for example, copies=2
in a preferred content expression lets content be dropped only when there are
currently 3 copies of it, including the repo it's being dropped from. This is
different than running git annex drop --copies=2, which will drop files that
currently have 2 copies.

copies=trustlevel:number
Matches only files that git-annex believes have the specified number copies, on
remotes with the specified trust level. For example, copies=trusted:2

To match any trust level at or higher than a given level, use trustlevel+. For
example, copies=semitrusted+:2

copies=groupname:number
Matches only files that git-annex believes have the specified number of copies, on
remotes in the specified group. For example, copies=archive:2

Preferred content expressions have no equivalent to the --in option, but groups can
accomplish similar things. You can add repositories to groups, and match against
the groups in a preferred content expression. So rather than --in=usbdrive, put all
the USB drives into a "transfer" group, and use copies=transfer:1

lackingcopies=number
Matches only files that git-annex believes need the specified number or more
additional copies to be made in order to satisfy their numcopies settings.

approxlackingcopies=number
Like lackingcopies, but does not look at .gitattributes annex.numcopies settings.
This makes it significantly faster.

inbackend=name
Matches only files whose content is stored using the specified key-value backend.

securehash
Matches only files whose content is hashed using a cryptographically secure
function.

inallgroup=groupname
Matches only files that git-annex believes are present in all repositories in the
specified group.

smallerthan=size / largerthan=size
Matches only files whose content is smaller than, or larger than the specified
size.

The size can be specified with any commonly used units, for example, "0.5 gb" or
"100 KiloBytes"

metadata=field=glob
Matches only files that have a metadata field attached with a value that matches
the glob. The values of metadata fields are matched case insensitively.

To match a tag "done", use metadata=tag=done

To match author metadata, use metadata=author=*Smith

metadata=field<number / metadata=field>number

metadata=field<=number / metadata=field>=number
Matches only files that have a metadata field attached with a value that is a
number and is less than or greater than the specified number.

To match PDFs with between 100 and 200 pages (assuming something has set that
metadata), use metadata=pagecount>=100 and metadata=pagecount<=200

present
Makes content be wanted if it's present, but not otherwise.

This leaves it up to you to use git-annex manually to move content around. You can
use this to avoid preferred content settings from affecting a subdirectory. For
example: auto/* or (include=ad-hoc/* and present)

Note that not present is a very bad thing to put in a preferred content expression.
It'll make it want to get content that's not present, and drop content that is
present! Don't go there..

inpreferreddir
Makes content be preferred if it's in a directory (located anywhere in the tree)
with a particular name.

The name of the directory can be configured using git annex enableremote $remote
preferreddir=$dirname

(If no directory name is configured, it uses "public" by default.)

standard
git-annex comes with some built-in preferred content expressions, that can be used
with repositories that are in some standard groups such as "client" and "transfer".

When a repository is in exactly one such group, you can use the "standard" keyword
in its preferred content expression, to match whatever content the group's
expression matches.

Most often, the whole preferred content expression is simply "standard". But, you
can do more complicated things, for example: standard or include=otherdir/*

groupwanted
The "groupwanted" keyword can be used to refer to a preferred content expression
that is associated with a group, as long as there is exactly one such expression
amoung the groups a repository is in. This is like the "standard" keyword, but you
can configure the preferred content expressions using git annex groupwanted.

When writing a groupwanted preferred content expression, you can use all the
keywords documented here, including "standard". (But not "groupwanted".)

For example, to make a variant of the standard client preferred content expression
that does not want files in the "out" directory, you could run: git annex
groupwanted client "standard and exclude=out/*"

Then repositories that are in the client group and have their preferred content
expression set to "groupwanted" will use that, while other client repositories that
have their preferred content expression set to "standard" will use the standard
expression.

Or, you could make a new group, with your own custom preferred content expression
tuned for your needs, and every repository you put in this group and make its
preferred content be "groupwanted" will use it.

For example, the archive group only wants to archive 1 copy of each file, spread
among every repository in the group. Here's how to configure a group named
redundantarchive, that instead wants to contain 3 copies of each file:

git annex groupwanted redundantarchive "not (copies=redundantarchive:3)"
for repo in foo bar baz; do
git annex group $repo redundantarchive
git annex wanted $repo groupwanted
done

unused Matches only keys that git annex unused has determined to be unused.

This is related the the --unused option. However, putting unused in a preferred
content expression doesn't make git-annex consider those unused keys. So when git-
annex is only checking preferred content expressions against files in the
repository (which are obviously used), unused in a preferred content expression
won't match anything.

So when is unused useful in a preferred content expression?

Using git annex sync --content --all will operate on all files, including unused
ones, and take unused in preferred content expressions into account.

The git-annex assistant periodically scans for unused files, and moves them to some
repository whose preferred content expression says it wants them. (Or, if
annex.expireunused is set, it may just delete them.)

anything
Always matches.

nothing
Never matches. (Same as "not anything")

not expression
Inverts what the expression matches. For example, not include=archive/* is the same
as exclude=archive/*

and / or / ( expression )
These can be used to build up more complicated expressions.

TESTING

       To check at the command line which files are matched by a repository's  preferred  content
       settings, you can use the --want-get and --want-drop options.

       For example, git annex find --want-get --not --in . will find all the files that git annex
       get --auto will want to get, and git annex find --want-drop --in . will find all the files
       that git annex drop --auto will want to drop.

AUTHOR