docs/frontends/CLI.rst: Unicode arguments to 'tahoe' work on Windows as of v1.7.1.

[tahoe-lafs/tahoe-lafs.git] / docs / frontends / CLI.rst

======================
The Tahoe CLI commands
======================

1.  `Overview`_
2.  `CLI Command Overview`_
3.  `Node Management`_
4.  `Filesystem Manipulation`_

    1.  `Starting Directories`_
    2.  `Command Syntax Summary`_
    3.  `Command Examples`_

5.  `Storage Grid Maintenance`_
6.  `Debugging`_


Overview
========

Tahoe provides a single executable named "``tahoe``", which can be used to
create and manage client/server nodes, manipulate the filesystem, and perform
several debugging/maintenance tasks.

This executable lives in the source tree at "``bin/tahoe``". Once you've done a
build (by running "make"), ``bin/tahoe`` can be run in-place: if it discovers
that it is being run from within a Tahoe source tree, it will modify sys.path
as necessary to use all the source code and dependent libraries contained in
that tree.

If you've installed Tahoe (using "``make install``", or by installing a binary
package), then the tahoe executable will be available somewhere else, perhaps
in ``/usr/bin/tahoe``. In this case, it will use your platform's normal
PYTHONPATH search paths to find the tahoe code and other libraries.


CLI Command Overview
====================

The "``tahoe``" tool provides access to three categories of commands.

* node management: create a client/server node, start/stop/restart it
* filesystem manipulation: list files, upload, download, delete, rename
* debugging: unpack cap-strings, examine share files

To get a list of all commands, just run "``tahoe``" with no additional
arguments. "``tahoe --help``" might also provide something useful.

Running "``tahoe --version``" will display a list of version strings, starting
with the "allmydata" module (which contains the majority of the Tahoe
functionality) and including versions for a number of dependent libraries,
like Twisted, Foolscap, pycryptopp, and zfec.


Node Management
===============

"``tahoe create-node [NODEDIR]``" is the basic make-a-new-node command. It
creates a new directory and populates it with files that will allow the
"``tahoe start``" command to use it later on. This command creates nodes that
have client functionality (upload/download files), web API services
(controlled by the 'webport' file), and storage services (unless
"--no-storage" is specified).

NODEDIR defaults to ~/.tahoe/ , and newly-created nodes default to
publishing a web server on port 3456 (limited to the loopback interface, at
127.0.0.1, to restrict access to other programs on the same host). All of the
other "``tahoe``" subcommands use corresponding defaults.

"``tahoe create-client [NODEDIR]``" creates a node with no storage service.
That is, it behaves like "``tahoe create-node --no-storage [NODEDIR]``".
(This is a change from versions prior to 1.6.0.)

"``tahoe create-introducer [NODEDIR]``" is used to create the Introducer node.
This node provides introduction services and nothing else. When started, this
node will produce an introducer.furl, which should be published to all
clients.

"``tahoe create-key-generator [NODEDIR]``" is used to create a special
"key-generation" service, which allows a client to offload their RSA key
generation to a separate process. Since RSA key generation takes several
seconds, and must be done each time a directory is created, moving it to a
separate process allows the first process (perhaps a busy wapi server) to
continue servicing other requests. The key generator exports a FURL that can
be copied into a node to enable this functionality.

"``tahoe run [NODEDIR]``" will start a previously-created node in the foreground.

"``tahoe start [NODEDIR]``" will launch a previously-created node. It will launch
the node into the background, using the standard Twisted "twistd"
daemon-launching tool. On some platforms (including Windows) this command is
unable to run a daemon in the background; in that case it behaves in the
same way as "``tahoe run``".

"``tahoe stop [NODEDIR]``" will shut down a running node.

"``tahoe restart [NODEDIR]``" will stop and then restart a running node. This is
most often used by developers who have just modified the code and want to
start using their changes.


Filesystem Manipulation
=======================

These commands let you exmaine a Tahoe filesystem, providing basic
list/upload/download/delete/rename/mkdir functionality. They can be used as
primitives by other scripts. Most of these commands are fairly thin wrappers
around wapi calls.

By default, all filesystem-manipulation commands look in ~/.tahoe/ to figure
out which Tahoe node they should use. When the CLI command uses wapi calls,
it will use ~/.tahoe/node.url for this purpose: a running Tahoe node that
provides a wapi port will write its URL into this file. If you want to use
a node on some other host, just create ~/.tahoe/ and copy that node's wapi
URL into this file, and the CLI commands will contact that node instead of a
local one.

These commands also use a table of "aliases" to figure out which directory
they ought to use a starting point. This is explained in more detail below.

As of Tahoe v1.7 (v1.7.1 on Windows), passing non-ASCII characters to the
CLI should work. On Unix, the command-line arguments are assumed to use the
character encoding specified by the current locale.

Starting Directories
--------------------

As described in `docs/architecture.rst <../architecture.rst>`_, the
Tahoe-LAFS distributed filesystem consists of a collection of directories
and files, each of which has a "read-cap" or a "write-cap" (also known as
a URI). Each directory is simply a table that maps a name to a child file
or directory, and this table is turned into a string and stored in a
mutable file. The whole set of directory and file "nodes" are connected
together into a directed graph.

To use this collection of files and directories, you need to choose a
starting point: some specific directory that we will refer to as a
"starting directory".  For a given starting directory, the "``ls
[STARTING_DIR]:``" command would list the contents of this directory,
the "``ls [STARTING_DIR]:dir1``" command would look inside this directory
for a child named "dir1" and list its contents, "``ls
[STARTING_DIR]:dir1/subdir2``" would look two levels deep, etc.

Note that there is no real global "root" directory, but instead each
starting directory provides a different, possibly overlapping
perspective on the graph of files and directories.

Each tahoe node remembers a list of starting points, named "aliases",
in a file named ~/.tahoe/private/aliases . These aliases are short UTF-8
encoded strings that stand in for a directory read- or write- cap. If
you use the command line "``ls``" without any "[STARTING_DIR]:" argument,
then it will use the default alias, which is "tahoe", therefore "``tahoe
ls``" has the same effect as "``tahoe ls tahoe:``".  The same goes for the
other commands which can reasonably use a default alias: get, put,
mkdir, mv, and rm.

For backwards compatibility with Tahoe-1.0, if the "tahoe": alias is not
found in ~/.tahoe/private/aliases, the CLI will use the contents of
~/.tahoe/private/root_dir.cap instead. Tahoe-1.0 had only a single starting
point, and stored it in this root_dir.cap file, so Tahoe-1.1 will use it if
necessary. However, once you've set a "tahoe:" alias with "``tahoe set-alias``",
that will override anything in the old root_dir.cap file.

The Tahoe CLI commands use the same filename syntax as scp and rsync
-- an optional "alias:" prefix, followed by the pathname or filename.
Some commands (like "tahoe cp") use the lack of an alias to mean that
you want to refer to a local file, instead of something from the tahoe
virtual filesystem. [TODO] Another way to indicate this is to start
the pathname with a dot, slash, or tilde.

When you're dealing a single starting directory, the "tahoe:" alias is
all you need. But when you want to refer to something that isn't yet
attached to the graph rooted at that starting directory, you need to
refer to it by its capability. The way to do that is either to use its
capability directory as an argument on the command line, or to add an
alias to it, with the "tahoe add-alias" command. Once you've added an
alias, you can use that alias as an argument to commands.

The best way to get started with Tahoe is to create a node, start it, then
use the following command to create a new directory and set it as your
"tahoe:" alias::

 tahoe create-alias tahoe

After that you can use "``tahoe ls tahoe:``" and
"``tahoe cp local.txt tahoe:``", and both will refer to the directory that
you've just created.

SECURITY NOTE: For users of shared systems
``````````````````````````````````````````

Another way to achieve the same effect as the above "tahoe create-alias"
command is::

 tahoe add-alias tahoe `tahoe mkdir`

However, command-line arguments are visible to other users (through the
'ps' command, or the Windows Process Explorer tool), so if you are using a
tahoe node on a shared host, your login neighbors will be able to see (and
capture) any directory caps that you set up with the "``tahoe add-alias``"
command.

The "``tahoe create-alias``" command avoids this problem by creating a new
directory and putting the cap into your aliases file for you. Alternatively,
you can edit the NODEDIR/private/aliases file directly, by adding a line like
this::

 fun: URI:DIR2:ovjy4yhylqlfoqg2vcze36dhde:4d4f47qko2xm5g7osgo2yyidi5m4muyo2vjjy53q4vjju2u55mfa

By entering the dircap through the editor, the command-line arguments are
bypassed, and other users will not be able to see them. Once you've added the
alias, no other secrets are passed through the command line, so this
vulnerability becomes less significant: they can still see your filenames and
other arguments you type there, but not the caps that Tahoe uses to permit
access to your files and directories.


Command Syntax Summary
----------------------

tahoe add-alias alias cap

tahoe create-alias alias

tahoe list-aliases

tahoe mkdir

tahoe mkdir [alias:]path

tahoe ls [alias:][path]

tahoe webopen [alias:][path]

tahoe put [--mutable] [localfrom:-]

tahoe put [--mutable] [localfrom:-] [alias:]to

tahoe put [--mutable] [localfrom:-] [alias:]subdir/to

tahoe put [--mutable] [localfrom:-] dircap:to

tahoe put [--mutable] [localfrom:-] dircap:./subdir/to

tahoe put [localfrom:-] mutable-file-writecap

tahoe get [alias:]from [localto:-]

tahoe cp [-r] [alias:]frompath [alias:]topath

tahoe rm [alias:]what

tahoe mv [alias:]from [alias:]to

tahoe ln [alias:]from [alias:]to

tahoe backup localfrom [alias:]to

Command Examples
----------------

``tahoe mkdir``

 This creates a new empty unlinked directory, and prints its write-cap to
 stdout. The new directory is not attached to anything else.

``tahoe add-alias fun DIRCAP``

 An example would be::

  tahoe add-alias fun URI:DIR2:ovjy4yhylqlfoqg2vcze36dhde:4d4f47qko2xm5g7osgo2yyidi5m4muyo2vjjy53q4vjju2u55mfa

 This creates an alias "fun:" and configures it to use the given directory
 cap. Once this is done, "tahoe ls fun:" will list the contents of this
 directory. Use "tahoe add-alias tahoe DIRCAP" to set the contents of the
 default "tahoe:" alias.

``tahoe create-alias fun``

 This combines "``tahoe mkdir``" and "``tahoe add-alias``" into a single step.

``tahoe list-aliases``

 This displays a table of all configured aliases.

``tahoe mkdir subdir``

``tahoe mkdir /subdir``

 This both create a new empty directory and attaches it to your root with the
 name "subdir".

``tahoe ls``

``tahoe ls /``

``tahoe ls tahoe:``

``tahoe ls tahoe:/``

 All four list the root directory of your personal virtual filesystem.

``tahoe ls subdir``

 This lists a subdirectory of your filesystem.

``tahoe webopen``

``tahoe webopen tahoe:``

``tahoe webopen tahoe:subdir/``

``tahoe webopen subdir/``

 This uses the python 'webbrowser' module to cause a local web browser to
 open to the web page for the given directory. This page offers interfaces to
 add, dowlonad, rename, and delete files in the directory. If not given an
 alias or path, opens "tahoe:", the root dir of the default alias.

``tahoe put file.txt``

``tahoe put ./file.txt``

``tahoe put /tmp/file.txt``

``tahoe put ~/file.txt``

 These upload the local file into the grid, and prints the new read-cap to
 stdout. The uploaded file is not attached to any directory. All one-argument
 forms of "``tahoe put``" perform an unlinked upload.

``tahoe put -``

``tahoe put``

 These also perform an unlinked upload, but the data to be uploaded is taken
 from stdin.

``tahoe put file.txt uploaded.txt``

``tahoe put file.txt tahoe:uploaded.txt``

 These upload the local file and add it to your root with the name
 "uploaded.txt"

``tahoe put file.txt subdir/foo.txt``

``tahoe put - subdir/foo.txt``

``tahoe put file.txt tahoe:subdir/foo.txt``

``tahoe put file.txt DIRCAP:./foo.txt``

``tahoe put file.txt DIRCAP:./subdir/foo.txt``

 These upload the named file and attach them to a subdirectory of the given
 root directory, under the name "foo.txt". Note that to use a directory
 write-cap instead of an alias, you must use ":./" as a separator, rather
 than ":", to help the CLI parser figure out where the dircap ends. When the
 source file is named "-", the contents are taken from stdin.

``tahoe put file.txt --mutable``

 Create a new mutable file, fill it with the contents of file.txt, and print
 the new write-cap to stdout.

``tahoe put file.txt MUTABLE-FILE-WRITECAP``

 Replace the contents of the given mutable file with the contents of file.txt
 and prints the same write-cap to stdout.

``tahoe cp file.txt tahoe:uploaded.txt``

``tahoe cp file.txt tahoe:``

``tahoe cp file.txt tahoe:/``

``tahoe cp ./file.txt tahoe:``

 These upload the local file and add it to your root with the name
 "uploaded.txt".

``tahoe cp tahoe:uploaded.txt downloaded.txt``

``tahoe cp tahoe:uploaded.txt ./downloaded.txt``

``tahoe cp tahoe:uploaded.txt /tmp/downloaded.txt``

``tahoe cp tahoe:uploaded.txt ~/downloaded.txt``

 This downloads the named file from your tahoe root, and puts the result on
 your local filesystem.

``tahoe cp tahoe:uploaded.txt fun:stuff.txt``

 This copies a file from your tahoe root to a different virtual directory,
 set up earlier with "tahoe add-alias fun DIRCAP".

``tahoe rm uploaded.txt``

``tahoe rm tahoe:uploaded.txt``

 This deletes a file from your tahoe root.

``tahoe mv uploaded.txt renamed.txt``

``tahoe mv tahoe:uploaded.txt tahoe:renamed.txt``

 These rename a file within your tahoe root directory.

``tahoe mv uploaded.txt fun:``

``tahoe mv tahoe:uploaded.txt fun:``

``tahoe mv tahoe:uploaded.txt fun:uploaded.txt``

 These move a file from your tahoe root directory to the virtual directory
 set up earlier with "tahoe add-alias fun DIRCAP"

``tahoe backup ~ work:backups``

 This command performs a full versioned backup of every file and directory
 underneath your "~" home directory, placing an immutable timestamped
 snapshot in e.g. work:backups/Archives/2009-02-06_04:00:05Z/ (note that the
 timestamp is in UTC, hence the "Z" suffix), and a link to the latest
 snapshot in work:backups/Latest/ . This command uses a small SQLite database
 known as the "backupdb", stored in ~/.tahoe/private/backupdb.sqlite, to
 remember which local files have been backed up already, and will avoid
 uploading files that have already been backed up. It compares timestamps and
 filesizes when making this comparison. It also re-uses existing directories
 which have identical contents. This lets it run faster and reduces the
 number of directories created.

 If you reconfigure your client node to switch to a different grid, you
 should delete the stale backupdb.sqlite file, to force "tahoe backup" to
 upload all files to the new grid.

``tahoe backup --exclude=*~ ~ work:backups``

 Same as above, but this time the backup process will ignore any
 filename that will end with '~'. '--exclude' will accept any standard
 unix shell-style wildcards, have a look at
 http://docs.python.org/library/fnmatch.html for a more detailed
 reference.  You may give multiple '--exclude' options.  Please pay
 attention that the pattern will be matched against any level of the
 directory tree, it's still impossible to specify absolute path exclusions.

``tahoe backup --exclude-from=/path/to/filename ~ work:backups``

 '--exclude-from' is similar to '--exclude', but reads exclusion
 patterns from '/path/to/filename', one per line.

``tahoe backup --exclude-vcs ~ work:backups``

 This command will ignore any known file or directory that's used by
 version control systems to store metadata. The excluded names are:

  * CVS
  * RCS
  * SCCS
  * .git
  * .gitignore
  * .cvsignore
  * .svn
  * .arch-ids
  * {arch}
  * =RELEASE-ID
  * =meta-update
  * =update
  * .bzr
  * .bzrignore
  * .bzrtags
  * .hg
  * .hgignore
  * _darcs

Storage Grid Maintenance
========================

``tahoe manifest tahoe:``

``tahoe manifest --storage-index tahoe:``

``tahoe manifest --verify-cap tahoe:``

``tahoe manifest --repair-cap tahoe:``

``tahoe manifest --raw tahoe:``

 This performs a recursive walk of the given directory, visiting every file
 and directory that can be reached from that point. It then emits one line to
 stdout for each object it encounters.

 The default behavior is to print the access cap string (like URI:CHK:.. or
 URI:DIR2:..), followed by a space, followed by the full path name.

 If --storage-index is added, each line will instead contain the object's
 storage index. This (string) value is useful to determine which share files
 (on the server) are associated with this directory tree. The --verify-cap
 and --repair-cap options are similar, but emit a verify-cap and repair-cap,
 respectively. If --raw is provided instead, the output will be a
 JSON-encoded dictionary that includes keys for pathnames, storage index
 strings, and cap strings. The last line of the --raw output will be a JSON
 encoded deep-stats dictionary.

``tahoe stats tahoe:``

 This performs a recursive walk of the given directory, visiting every file
 and directory that can be reached from that point. It gathers statistics on
 the sizes of the objects it encounters, and prints a summary to stdout.


Debugging
=========

For a list of all debugging commands, use "tahoe debug".

"``tahoe debug find-shares STORAGEINDEX NODEDIRS..``" will look through one or
more storage nodes for the share files that are providing storage for the
given storage index.

"``tahoe debug catalog-shares NODEDIRS..``" will look through one or more
storage nodes and locate every single share they contain. It produces a report
on stdout with one line per share, describing what kind of share it is, the
storage index, the size of the file is used for, etc. It may be useful to
concatenate these reports from all storage hosts and use it to look for
anomalies.

"``tahoe debug dump-share SHAREFILE``" will take the name of a single share file
(as found by "tahoe find-shares") and print a summary of its contents to
stdout. This includes a list of leases, summaries of the hash tree, and
information from the UEB (URI Extension Block). For mutable file shares, it
will describe which version (seqnum and root-hash) is being stored in this
share.

"``tahoe debug dump-cap CAP``" will take a URI (a file read-cap, or a directory
read- or write- cap) and unpack it into separate pieces. The most useful
aspect of this command is to reveal the storage index for any given URI. This
can be used to locate the share files that are holding the encoded+encrypted
data for this file.

"``tahoe debug repl``" will launch an interactive python interpreter in which
the Tahoe packages and modules are available on sys.path (e.g. by using 'import
allmydata'). This is most useful from a source tree: it simply sets the
PYTHONPATH correctly and runs the 'python' executable.

"``tahoe debug corrupt-share SHAREFILE``" will flip a bit in the given
sharefile. This can be used to test the client-side verification/repair code.
Obviously, this command should not be used during normal operation.