Ubuntu Manpage: shatag - tag files with their SHA-256 checksums

NAME

       shatag - tag files with their SHA-256 checksums

SYNOPSIS

       shatag [-fhlLqrstuv0] [-d DATABASE] [-n NAME] [-R NAME]...  [FILES]...

DESCRIPTION

       shatag  is a tool for computing and caching SHA-256 file checksums, and efficiently search
       for identical  file  across  systems.  Checksums  are  stored  using  the  POSIX  Extended
       Attributes  filesystem  facility,  and  are  preserved  when  files  are moved or renamed.
       Checksums can be fetched from a remote host and stored in  an  sqlite  database  for  fast
       lookups.

OPTIONS

When invoked with no options, shatag just displays the cached, valid checksums. If no
files are specified, it applies to all non-hidden files in the current directory. The
output format is identical to the one of the sha256sum command.

-0, --null
Instead of outputting one record per line (like sha256sum does,) separate records
with null characters.

-c, --canonical
Show canonical (full path) file names.

-d DATABASE, --database DATABASE
Set the path of the SQLite database to query when using -l , -L or -p (The default
path is $HOME/.shatagdb, overridable from the config file)

Instead of a file name, a PostgreSQL database can be specified with a prefix of
"pg:" followed by a psycopg2 DSN string, like:

"pg:dbname=shatag user=myuser password=mypassword host=192.168.1.3"

-f, --force
When running with -t or -u , force recompute the checksum and overwrite the old
one, even if the timestamp indicates a good checksum.

-h, --help
Displays the help message

-l, --lookup
Instead of displaying the checksums, look them up against the local database and
indicate if the file exists. A yellow - mark indicates that the file does not exist
somewhere else, a green = that the file exists at one or several remote locations,
a red + that the file has a duplicate on the local system, and a magenta * that the
file is empty.

-L, --lookup-verbose
Instead of displaying the checksums, look them up against the local database.
Print all the known remote locations for identical files.

-n NAME, --name NAME
Name of local storage (defaults to canonical local host name). This needs to be
correct if the local database contains entries for this own host.

-p, --put
Record found tags in the database, for duplicate detection.

-q, --quiet
Do not display the valid checksums when they are found.

-r, --recursive
Recurse trough subdirectories

-R NAME, --remote NAME
When using -l or -L , This is used to restrict the set of remote names to consider.
If present, other storages will be ignored.

-s, --scrub
Recompute the checksum even if the timestamp indicates it would not be needed, and
report inconsistencies. Useful to detect silent corruption.

-t, --tag
Compute new checksums for files that don't have one, or when it is outdated.

-u, --update
Recompute the outdated checksums only. Be aware that this can behave counter-
intuitively; outdated checksums will only exists for files that have been appended
to or partially modified. Many programs dealing with small files (some well-known
text editors, notably) will overwrite the whole file when saving, and the new file
will be lacking a checksum entirely. For these cases, use -t instead.

-v, --verbose
Report encoutered files that have an outated or missing checksum.

EXAMPLES

       Retag a whole directory and record everything to the database:
              shatag -pqrt .

       Check files in the current directory for remote duplicates:
              shatag -l

       Show alternate locations for duplicates of a single file:
              shatag -L somefile

FILES

       ~/.shatagrc
              YAML  configuration  file.  Currently  has  only  two  possible configuration keys:
              "database", which sets the database path (by default, ~/.shatagdb) and  "name"  for
              the volume name in the database (default to canonical host name.)

              Examples:

              database:  /var/lib/shatag.db    #  sqlite3  backend  database:  "pg: dbname=shatag
              host=localhost  user=shatag  password=xxxsecretpasswordxxx"   #  postgres   backend
              database:   http://service.com/shatag     #   http   backend   database:  insecure-
              https://service.com/shatag  # http backend, skip ssl certificate verification

BUGS

       Support for non-ASCII filenames across systems of different and/or inconsistent  encodings
       have not been fully tested.

       Not all option combinations are sensible.

REPORTING BUGS

       Report shatag bugs to the bugtracker at http://bitbucket.org/maugier/shatag,