Provided by: bup-doc_0.29-3_all 
NAME
bup-index - print and/or update the bup filesystem index
SYNOPSIS
bup index <-p|-m|-s|-u|--clear|--check> [-H] [-l] [-x] [--fake-valid] [--no-check-device] [--fake-in‐
valid] [-f indexfile] [--exclude path] [--exclude-from filename] [--exclude-rx pattern] [--ex‐
clude-rx-from filename] [-v] <paths...>
DESCRIPTION
bup index manipulates the filesystem index, which is a cache of absolute paths and their metadata (att‐
tributes, SHA-1 hashes, etc.). The bup index is similar in function to the git(1) index, and the default
index can be found in $BUP_DIR/bupindex.
Creating a backup in bup consists of two steps: updating the index with bup index, then actually backing
up the files (or a subset of the files) with bup save. The separation exists for these reasons:
1. There is more than one way to generate a list of files that need to be backed up. For example, you
might want to use inotify(7) or dnotify(7).
2. Even if you back up files to multiple destinations (for added redundancy), the file names, attributes,
and hashes will be the same each time. Thus, you can save the trouble of repeatedly re-generating the
list of files for each backup set.
3. You may want to use the data tracked by bup index for other purposes (such as speeding up other pro‐
grams that need the same information).
NOTES
At the moment, bup will ignore Linux attributes (cf. chattr(1) and lsattr(1)) on some systems (any
big-endian systems where sizeof(long) < sizeof(int)). This is because the Linux kernel and FUSE current‐
ly disagree over the type of the attr system call arguments, and so on big-endian systems there's no way
to get the results without the risk of stack corruption (http://lwn.net/Articles/575846/). In these sit‐
uations, bup will print a warning the first time Linux attrs are relevant during any index/save/restore
operation.
bup makes accommodations for the expected "worst-case" filesystem timestamp resolution -- currently one
second; examples include VFAT, ext2, ext3, small ext4, etc. Since bup cannot know the filesystem time‐
stamp resolution, and could be traversing multiple filesystems during any given run, it always assumes
that the resolution may be no better than one second.
As a practical matter, this means that index updates are a bit imprecise, and so bup save may occasional‐
ly record filesystem changes that you didn't expect. That's because, during an index update, if bup en‐
counters a path whose actual timestamps are more recent than one second before the update started, bup
will set the index timestamps for that path (mtime and ctime) to exactly one second before the run, --
effectively capping those values.
This ensures that no subsequent changes to those paths can result in timestamps that are identical to
those in the index. If that were possible, bup could overlook the modifications.
You can see the effect of this behavior in this example (assume that less than one second elapses between
the initial file creation and first index run):
$ touch src/1 src/2
# A "sleep 1" here would avoid the unexpected save.
$ bup index src
$ bup save -n src src # Saves 1 and 2.
$ date > src/1
$ bup index src
$ date > src/2 # Not indexed.
$ bup save -n src src # But src/2 is saved anyway.
Strictly speaking, bup should not notice the change to src/2, but it does, due to the accommodations de‐
scribed above.
MODES
-u, --update
recursively update the index for the given paths and their descendants. One or more paths must be
specified, and if a path ends with a symbolic link, the link itself will be indexed, not the tar‐
get. If no mode option is given, --update is the default, and paths may be excluded by the --ex‐
clude, --exclude-rx, and --one-file-system options.
-p, --print
print the contents of the index. If paths are given, shows the given entries and their descen‐
dants. If no paths are given, shows the entries starting at the current working directory (.).
-m, --modified
prints only files which are marked as modified (ie. changed since the most recent backup) in the
index. Implies -p.
-s, --status
prepend a status code (A, M, D, or space) before each path. Implies -p. The codes mean, respec‐
tively, that a file is marked in the index as added, modified, deleted, or unchanged since the
last backup.
--check
carefully check index file integrity before and after updating. Mostly useful for automated
tests.
--clear
clear the default index.
OPTIONS
-H, --hash
for each file printed, prepend the most recently recorded hash code. The hash code is normally
generated by bup save. For objects which have not yet been backed up, the hash code will be
0000000000000000000000000000000000000000. Note that the hash code is printed even if the file is
known to be modified or deleted in the index (ie. the file on the filesystem no longer matches
the recorded hash). If this is a problem for you, use --status.
-l, --long
print more information about each file, in a similar format to the -l option to ls(1).
-x, --xdev, --one-file-system
don't cross filesystem boundaries when traversing the filesystem -- though as with tar and rsync,
the mount points themselves will still be indexed. Only applicable if you're using -u.
--fake-valid
mark specified paths as up-to-date even if they aren't. This can be useful for testing, or to
avoid unnecessarily backing up files that you know are boring.
--fake-invalid
mark specified paths as not up-to-date, forcing the next "bup save" run to re-check their con‐
tents.
-f, --indexfile=indexfile
use a different index filename instead of $BUP_DIR/bupindex.
--exclude=path
exclude path from the backup (may be repeated).
--exclude-from=filename
read --exclude paths from filename, one path per-line (may be repeated). Ignore completely empty
lines.
--exclude-rx=pattern
exclude any path matching pattern, which must be a Python regular expression
(http://docs.python.org/library/re.html). The pattern will be compared against the full path,
without anchoring, so "x/y" will match "ox/yard" or "box/yards". To exclude the contents of /tmp,
but not the directory itself, use "^/tmp/.". (may be repeated)
Examples:
• '/foo$' - 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, but not /tmp itself
--exclude-rx-from=filename
read --exclude-rx patterns from filename, one pattern per-line (may be repeated). Ignore com‐
pletely empty lines.
--no-check-device
don't mark an entry invalid if the device number (stat(2) st_dev) changes. This can be useful
when indexing remote, automounted, or snapshot filesystems (LVM, Btrfs, etc.), where the device
number isn't fixed.
-v, --verbose
increase log output during update (can be used more than once). With one -v, print each directory
as it is updated; with two -v, print each file too.
EXAMPLES
bup index -vux /etc /var /usr
SEE ALSO
bup-save(1), bup-drecurse(1), bup-on(1)
BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup debian/0.29-3 2017-04-01 bup-index(1)