bup-get(1)

NAME
bup-get - copy repository items (note CAUTION below)

SYNOPSIS
bup get [-s source-path] [-r host:path] OPTIONS <(METHOD ref [dest])>...

DESCRIPTION
bup get transfers the indicated refs from the source repository to the destination repository (respecting --bup-dir and BUP_DIR), according to the specified METHOD, which may be one of --ff, --ff:, --append, --append:, --pick, --pick:, --force-pick, --force-pick:, --new-tag, --new-tag:, --replace, --replace:, or --unnamed. By default it will --copy the data without alteration, but it can also --rewrite it, potentially changing the deduplication granularity, and --repair some kinds of damage. See the EXAMPLES below for a quick introduction.

The ref is the source repository reference of the object to be fetched, and the dest is the optional destination reference. A dest may only be specified for a METHOD whose name ends in a colon. For example:

        bup get -s /source/repo --ff foo
        bup get -s /source/repo --ff: foo/latest bar
        bup get -s /source/repo --pick: foo/2010-10-10-101010 bar
        bup get -s /source/repo --pick: foo/2010-10-10-101010 .tag/bar

The behavior of any given METHOD is determined in part by the ref and dest types, i.e. branch, save, tag, etc.

As a special case, if ref names the “latest” save symlink, then bup will act exactly as if the save that “latest” points to had been specified, rather than the “latest” symlink itself, so bup get foo/latest will actually be interpreted as something like bup get foo/2013-01-01-030405.

In some situations bup get will evaluate a branch operation according to whether or not it will be a “fast-forward” (which requires that any existing destination branch be an ancestor of the source).

An existing destination tag can only be overwritten by a --replace or --force-pick.

When a new commit is created (i.e. via --append, --pick, etc.), it will have the same author, author date, and message as the original, but a committer and committer date corresponding to the current user and time.

If requested by the appropriate options, bup will print the commit, tree, or tag hash for each destination reference updated. When relevant, the tree hash will be printed before the commit hash.

Local refs can be pushed to a remote repository with the --remote option, and remote refs can be pulled into a local repository via “bup on HOST get ...”. See bup-on(1) and the EXAMPLES below for further information.

CAUTION: This is one of the few bup commands that can modify your archives in intentionally destructive ways. Though if an attempt to join or restore the data you still care about succeeds after you’ve run this command, then that’s a fairly encouraging sign that it worked correctly. (The dev/compare-trees command in the source tree can be used to help test before/after results.)

METHODS

--ff ref, --ff: ref dest
    fast-forward dest to match ref. If dest is not specified and ref names a save, set dest to the save’s branch. If dest is not specified and ref names a branch or a tag, use the same name for dest.

--append ref, --append: ref dest
    append all of the commits represented by ref to dest as new commits. If ref names a directory/tree, append a new commit for that tree. If dest is not specified and ref names a save or branch, set dest to the ref branch name. If dest is not specified and ref names a tag, use the same name for dest.

--pick ref, --pick: ref dest
    append the single commit named by ref to dest as a new commit. If dest is not specified and ref names a save, set dest to the ref branch name. If dest is not specified and ref names a tag, use the same name for dest.

--force-pick ref, --force-pick: ref dest
    do the same thing as --pick, but don’t refuse to overwrite an existing tag, and if the tag refers to a commit, make it the parent of ref.

--new-tag ref, --new-tag: ref dest
    create a dest tag for ref, but refuse to overwrite an existing tag. If dest is not specified and ref names a tag, use the same name for dest.

--replace ref, --replace: ref dest
    clobber dest with ref, overwriting any existing tag, or replacing any existing branch. If dest is not specified and ref names a branch or tag, use the same name for dest.

--unnamed ref
    copy ref into the destination repository, without any name, leaving a potentially dangling reference until/unless the object named by ref is referred to some other way (cf. bup tag). Currently only compatible with --copy.

OPTIONS

-s path, -S url, --source path, --source-url url*
    use path or url as the source repository, instead of the default. See bup(1) REPOSITORY URLS for further information.

-r, --remote=[user@]host:[path], --remote=URL
    write the refs to the specified remote repository, by default via SSH. See bup(1) REMOTE OPTIONS for further information.

-c, --print-commits
    for each updated branch, print the new git commit id.

-t, --print-trees
    for each updated branch, print the new git tree id of the filesystem root.

--print-tags
    for each updated tag, print the new git id.

--copy
    copy the data without changes (i.e. without rewrites or repairs). This is the default.

--rewrite
    rewrite the data according to the destination repository configuration, e.g. its bup.split.files, and bup.split.trees values. Some incidental repairs may be performed during the transfer when they do not materially alter the result (see REPAIRS below). Currently, --rewrite, ---repair, or --copy must be specified whenever the source and destination repository configurations differ in a relevant way, and so far, --rewrite is only supported for appends and picks of saves (e.g. not trees).
    Note that rewriting a git-created save may, and for now will, introduce bup-related changes. Further, while tested, --rewrite is relatively new and so warrants even more caution (see CAUTION above) than bup get itself. Please consider validating the results carefully for now. This option is contextual (see CONTEXTUAL OPTIONS).

--repair
    in addition to what --rewrite does, perform all known repairs during the transfer. See REPAIRS below. This option is contextual (see CONTEXTUAL OPTIONS).

--repair-id ID
    set the repair session identifier, defaults to a UUID (v4). This identifier will be included in any --repairs made during the transfer. Currently, the identifier must be ASCII and must not include control characters or DEL (i.e. must be comprised of bytes >= 20 and < 127). This option is contextual (see CONTEXTUAL OPTIONS).

--ignore-missing
    ignore missing objects encountered during a transfer. Currently only supported by --unnamed, and potentially dangerous.

--exclude-rx=pattern
    exclude any path matching pattern, which must be a Python regular expression (http://docs.python.org/library/re.html). The pattern will be compared against the full path, without anchoring, so “x/y” will match “ox/yard” or “box/yards”. To exclude the contents of /tmp, but not the directory itself, use “^/tmp/.”. (may be repeated)
    Examples:

    •   /foo$ - exclude any file named foo

    •   /foo/$ - exclude any directory named foo

    •   /foo/. - exclude the content of any directory named foo

    •   ^/tmp/. - exclude root-level tmp’s content Only supported when rewriting or repairing. This option is contextual (see CONTEXTUAL OPTIONS).

--exclude-rx-from=filename
    read –exclude-rx patterns from filename, one pattern per-line (may be repeated). Ignore completely empty lines. Only supported when rewriting. This option is contextual (see CONTEXTUAL OPTIONS).

--no-excludes
    forget any previous --exclude-rx or --exclude-rx-from options. This option is contextual (see CONTEXTUAL OPTIONS).

-v, --verbose
    increase verbosity (can be used more than once). With -v, print the name of every item fetched, with -vv add directory names, and with -vvv add every filename.

--bwlimit=bytes/sec
    don’t transmit more than bytes/sec bytes per second to the server. This can help avoid sucking up all your network bandwidth. Use a suffix like k, M, or G to specify multiples of 1024, 1024*1024, 1024*1024*1024 respectively.

-#, --compress=#
    set the compression level to # (a value from 0-9, where 9 is the highest and 0 is no compression). Defaults to a configured pack.compression or core.compression, or 1 (fast, loose compression).

CONTEXTUAL OPTIONS
Some options like --repair and --ignore-missing can differ across METHODs, and each option changes the context for the next METHOD. So you can have

        bup get ... --ignore-missing --unnamed REF \
            --no-ignore-missing --rewrite --append REF

Without --no-ignore-missing this command would fail because --ignore-missing is incompatible with --rewrite.

Changing the currently active excludes is expensive because at the moment the cache of remembered rewrites must be cleared whenever a METHODs excludes differ from those for the previous METHOD.

REPAIRS
bup get can fix (or mitigate) a number of known issues during the transfer when --repair is requested, and a subset of “incidental” repairs may also be performed during a --rewrite.

•   Versions of bup at or after 0.25 and before 0.30.1 might rarely drop metadata entries for non-directories (which can be detected by bup-validate-refs(1) --bupm). This makes the metadata for all of the other non-directory paths in the same directory unusable (ambiguous). When such an abridged .bupm is detected, --repair drops all of the .bupm entries except the one for the directory itself, “.”, and so the affected paths lose most or all of their metadata (ownership, permissions, timestamps, etc.). These paths will have restrictive permissions (as if via umask 077) when presented, e.g. via bup-restore(1), bup-ls(1), etc.

•   Use of bup get or bup gc versions before 0.33.5 could cause repositories to end up with missing objects (which can be detected by bup-validate-object-links(1)). To fix affected trees, --repair substitutes synthesized “repair files” for any paths with missing objects. Note that there is currently no support for retrieving the unaffected parts of split files; the entire file is replaced with a repair file. These repair files contain the --repair-id and information about the replacement. Support for split trees was added after the problem was fixed, and so should be unaffected. See the 0.33.5 release notes (0.33.5-from-0.33.4.md) (https://github.com/bup/bup/blob/main/note/0.33.5-from-0.33.4.md) for additional information.

“Incidental” repairs may also be performed — repairs that do not functionally alter the result. For example, bup records symlink targets in two places, but generally only refers to one of them. If the other one is missing, it can and will be restored from the first.

EXAMPLES

        # Update or copy the archives branch in src-repo to the local repository.
        $ bup get -s src-repo --ff archives
        # Append a particular archives save to the pruned-archives branch.
        $ bup get -s src-repo --pick: archives/2013-01-01-030405 pruned-archives
        # Update or copy the archives branch on remotehost to the local
        # repository.
        $ bup on remotehost get --ff archives
        # Update or copy the local branch archives to remotehost.
        $ bup get -r remotehost: --ff archives
        # Update or copy the archives branch in src-repo to remotehost.
        $ bup get -s src-repo -r remotehost: --ff archives
        # Update the archives-2 branch on remotehost to match archives.
        # If archives-2 exists and is not an ancestor of archives, bup
        # will refuse.
        $ bup get -r remotehost: --ff: archives archives-2
        # Replace the contents of branch y with those of x.
        $ bup get --replace: x y
        # Copy the latest local save from the archives branch to the
        # remote tag foo.
        $ bup get -r remotehost: --pick: archives/latest .tag/foo
        # Or if foo already exists:
        $ bup get -r remotehost: --force-pick: archives/latest .tag/foo
        # Append foo (from above) to the local other-archives branch.
        $ bup on remotehost get --append: .tag/foo other-archives
        # Append only the /home directory from archives/latest to only-home.
        $ bup get -s "$BUP_DIR" --append: archives/latest/home only-home
        # Resplit (rewrite) the archives branch. Note that, done all at
        # once, this may require additional space up to the size of the
        # archives branch. The pick methods can do the rewriting more
        # selectively or incrementally. (Assume BUP_DIR has no split
        # settings.)
        #
        $ git --git-dir "$BUP_DIR" config bup.split.trees true
        $ git --git-dir "$BUP_DIR" config bup.split.files legacy:16
        $ bup get --rewrite --append: archives archives-resplit
        #
        # Check that archives-resplit looks OK, perhaps via trial
        # restores, joining it, etc. (see CAUTION above), and once
        # satisfied, perhaps...
        #
        $ bup rm archives
        $ bup gc
        $ git --git-dir "$BUP_DIR" branch -m archives-resplit archives
        #
        # Repair a single save.
        $ bup get --repair --pick archives/latest fixed
        #
        # Check that fixed/latest looks OK, perhaps via trial
        # restores, joining it, etc. (see CAUTION above).

EXIT STATUS
An exit status of 3 indicates that repairs were needed and were successful, and that no other errors occurred.

SEE ALSO
bup-on(1), bup-tag(1), ssh_config(5)

BUP
Part of the bup(1) suite.

AUTHORS
Rob Browning rlb@defaultvalue.org