Provided by: darcs_2.14.2-2build2_amd64 bug

NAME

       darcs - an advanced revision control system

SYNOPSIS

       darcs command <arguments|[options]>...

       Where the commands and their respective arguments are

       darcs help [<darcs_command> [darcs_subcommand]]
       darcs initialize [<directory>]
       darcs add <file|directory> ...
       darcs whatsnew [file|directory]...
       darcs record [file|directory]...
       darcs clone <repository> [<directory>]
       darcs pull [repository]...
       darcs push [repository]
       darcs move <source> ... <destination>
       darcs remove <file|directory> ...
       darcs replace <old> <new> <file> ...
       darcs log [file|directory]...
       darcs annotate [file|directory]
       darcs diff [file|directory]...
       darcs show contents [file]...
       darcs show dependencies
       darcs show files [file|directory]...
       darcs show index
       darcs show pristine
       darcs show repo
       darcs show authors
       darcs show tags
       darcs show patch-index
       darcs test [[initialization] command]
       darcs revert [file|directory]...
       darcs unrevert
       darcs amend [file|directory]...
       darcs rebase pull [repository]...
       darcs rebase apply <patchfile>
       darcs rebase suspend
       darcs rebase unsuspend
       darcs rebase obliterate
       darcs rebase log
       darcs rollback [file|directory]...
       darcs unrecord
       darcs obliterate
       darcs tag [tagname]
       darcs setpref <pref> <value>
       darcs send [repository]
       darcs apply <patchfile>
       darcs optimize clean
       darcs optimize http
       darcs optimize reorder
       darcs optimize enable-patch-index
       darcs optimize disable-patch-index
       darcs optimize compress
       darcs optimize uncompress
       darcs optimize relink
       darcs optimize pristine
       darcs optimize upgrade
       darcs optimize cache <directory> ...
       darcs dist
       darcs mark-conflicts [file|directory]...
       darcs repair
       darcs convert darcs-2 <source> [<destination>]
       darcs convert export
       darcs convert import [<directory>]
       darcs fetch [repository]...

DESCRIPTION

       Darcs is a free, open source revision control system. It is:

       •  Distributed: Every user has access to the full command set, removing boundaries between
          server and client or committer and non‐committers.

       •  Interactive: Darcs is easy to learn and efficient to use because it asks you  questions
          in response to simple commands, giving you choices in your work flow. You can choose to
          record one change in a file, while ignoring another. As you update from  upstream,  you
          can review each patch name, even the full `diff' for interesting patches.

       •  Smart:  Originally  developed  by  physicist  David  Roundy, darcs is based on a unique
          algebra of patches.  This smartness lets you respond to changing demands in  ways  that
          would otherwise not be possible. Learn more about spontaneous branches with darcs.

OPTIONS

       Different options are accepted by different Darcs commands.  Each command's most important
       options are listed in the COMMANDS section.  For a full list of all options accepted by  a
       particular command, run `darcs command --help'.

   Selecting Patches:
       The  --patches option yields patches with names matching an *extended* regular expression.
       See regex(7) for details.  The --matches  option  yields  patches  that  match  a  logical
       (Boolean) expression: one or more primitive expressions combined by grouping (parentheses)
       and the complement (not),  conjunction  (and)  and  disjunction  (or)  operators.   The  C
       notation for logic operators (!, && and ||) can also be used.

       -  --patches=regex  is a synonym for --matches='name regex' - --hash=HASH is a synonym for
       --matches='hash HASH' - --from-patch and --to-patch are synonyms for --from-match='name...
       and --to-match='name...  - --from-patch and --to-match can be unproblematically combined:
         `darcs log --from-patch='html.*documentation' --to-match='date 20040212'`

       The following primitive Boolean expressions are supported:

         exact STRING - check literal STRING is equal to patch name.
         name REGEX - match REGEX against patch name.
         author REGEX - match REGEX against patch author.
         hunk REGEX - match REGEX against contents of a hunk patch.
         comment REGEX - match REGEX against the full log message.
         hash HASH - match HASH against (a prefix of) the hash of a patch.
         date DATE - match DATE against the patch date.
         touch REGEX - match file paths for a patch.

       Here are some examples:

         darcs log --match 'exact "Resolve issue17: use dynamic memory allocation."'
         darcs log --match 'name issue17'
         darcs log --match 'name "^[Rr]esolve issue17\>"'
         darcs log --match 'author "David Roundy"'
         darcs log --match 'author droundy'
         darcs log --match 'author droundy@darcs.net'
         darcs log --match 'hunk "foo = 2"'
         darcs log --match 'hunk "^instance .* Foo where$"'
         darcs log --match 'comment "prevent deadlocks"'
         darcs log --match 'hash c719567e92c3b0ab9eddd5290b705712b8b918ef'
         darcs log --match 'hash c7195'
         darcs log --match 'date "2006-04-02 22:41"'
         darcs log --match 'date "tea time yesterday"'
         darcs log --match 'touch src/foo.c'
         darcs log --match 'touch src/'
         darcs log --match 'touch "src/*.(c|h)"'

COMMANDS

       darcs help [<darcs_command> [darcs_subcommand]]
           Without  arguments,  `darcs  help`  prints  a categorized list of darcs commands and a
           short description of each one.  With  an  extra  argument,  `darcs  help  foo`  prints
           detailed help about the darcs command foo.

   Most used/starting out:
       darcs initialize [<directory>]
           The  `darcs  initialize` command creates an empty repository in the current directory.
           This repository lives in a  new  `_darcs`  directory,  which  stores  version  control
           metadata and settings.

           Any  existing files and subdirectories become UNSAVED changes: record them with `darcs
           record --look-for-adds`.

           By default, patches of the new repository are in the darcs-2 semantics.  However it is
           possible  to  create  a  repository  in  darcs-1  semantics with the flag `--darcs-1`,
           althought this is not recommended except for sharing patches with a project that  uses
           patches in the darcs-1 semantics.

           Initialize is commonly abbreviated to `init`.

       darcs add <file|directory> ...
           Generally the working tree contains both files that should be version controlled (such
           as source code) and files that Darcs should ignore (such as executables compiled  from
           the  source  code).   The  `darcs  add`  command  is used to tell Darcs which files to
           version control.

           When an existing project is first imported into a Darcs repository, it  is  common  to
           run `darcs add -r *` or `darcs record -l` to add all initial source files into darcs.

           Adding symbolic links (symlinks) is not supported.

           Darcs  will  ignore  all  files and folders that look "boring".  The `--boring` option
           overrides this behaviour.

           Darcs will not add file if another file in the same folder has the same  name,  except
           for  case.  The `--case-ok` option overrides this behaviour.  Windows and OS X usually
           use filesystems that do not allow files a folder to have the same name except for case
           (for example, `ReadMe` and `README`).  If `--case-ok` is used, the repository might be
           unusable on those systems!

       darcs whatsnew [file|directory]...
           The `darcs whatsnew` command lists unrecorded changes to the  working  tree.   If  you
           specify  a  set  of  files and directories, only unrecorded changes to those files and
           directories are listed.

           With the `--summary` option, the changes are condensed to  one  line  per  file,  with
           mnemonics  to  indicate  the  nature  and extent of the change.  The `--look-for-adds`
           option causes candidates for `darcs  add`  to  be  included  in  the  summary  output.
           Summary mnemonics are as follows:

           *  `A  f` and `A d/` respectively mean an added file or directory.  * `R f` and `R d/`
           respectively mean a removed file or directory.  * `M f -N  +M  rP`  means  a  modified
           file, with `N` lines deleted, `M`
             lines  added,  and  `P`  lexical  replacements.   *  `f  -> g` means a moved file or
           directory.  * `a f` and `a d/` respectively mean a new, but unadded, file or
             directory, when using `--look-for-adds`.

             An exclamation mark (!) as in `R! foo.c`, means the change is known to
             conflict with a change in another patch.  The phrase `duplicated`
             means the change is known to be identical to a change in another patch.

           The `--machine-readable` option implies `--summary` while  making  it  more  parsable.
           Modified files are only shown as `M f`, and moves are shown in two lines: `F f` and `T
           g` (as in 'From f To g').

           By default, `darcs whatsnew` uses Darcs' internal format for  changes.   To  see  some
           context  (unchanged  lines)  around  each change, use the `--unified` option.  To view
           changes in conventional `diff` format, use the `darcs diff`  command;  but  note  that
           `darcs whatsnew` is faster.

           This  command  exits  unsuccessfully  (returns a non-zero exit status) if there are no
           unrecorded changes.

       darcs record [file|directory]...
           The `darcs record` command is used to create a patch from changes in the working tree.
           If you specify a set of files and directories, changes to other files will be skipped.

           Every patch has a name, an optional description, an author and a date.

           Darcs  will  launch a text editor (see `darcs help environment`) after the interactive
           selection, to let you enter the patch name (first  line)  and  the  patch  description
           (subsequent lines).

           You  can  supply the patch name in advance with the `-m` option, in which case no text
           editor is launched, unless you use `--edit-long-comment`.

           The patch description is an optional block of free-form text.  It is  used  to  supply
           additional  information  that  doesn't  fit  in the patch name.  For example, it might
           include a rationale of WHY the change was necessary.

           A technical difference between patch name and patch description, is that matching with
           the flag `-p` is only done on patch names.

           Finally,  the `--logfile` option allows you to supply a file that already contains the
           patch name and description.  This is useful if a previous record  failed  and  left  a
           `_darcs/patch_description.txt` file.

           Each  patch  is attributed to its author, usually by email address (for example, `Fred
           Bloggs <fred@example.net>`).  Darcs looks in several places for  this  author  string:
           the  `--author`  option,  the  files  `_darcs/prefs/author`  (in  the  repository) and
           `~/.darcs/author`  (in  your  home   directory),   and   the   environment   variables
           `$DARCS_EMAIL`  and  `$EMAIL`.   If  none of those exist, Darcs will prompt you for an
           author string and write it to `~/.darcs/author`.  Note that if you have more than  one
           email  address, you can put them all in `~/.darcs/author`, one author per line.  Darcs
           will still prompt you for an author, but it allows you to select from the list, or  to
           type in an alternative.

           If  you  want to manually define any explicit dependencies for your patch, you can use
           the `--ask-deps` flag. Some  dependencies  may  be  automatically  inferred  from  the
           patch's  content  and  cannot  be  removed.  A patch with specific dependencies can be
           empty.

           The patch date is generated automatically.  It  can  only  be  spoofed  by  using  the
           `--pipe` option.

           If  you  run record with the `--pipe` option, you will be prompted for the patch date,
           author, and the long comment. The long comment will extend until the end  of  file  or
           stdin  is  reached.  This interface is intended for scripting darcs, in particular for
           writing repository conversion scripts.  The prompts are intended mostly  as  a  useful
           guide (since scripts won't need them), to help you understand the input format. Here's
           an example of what the `--pipe` prompts look like:

               What is the date? Mon Nov 15 13:38:01 EST 2004
               Who is the author? David Roundy
               What is the log? One or more comment lines

           If a test command has been defined with `darcs setpref`, attempting to record a  patch
           will  cause  the  test command to be run in a clean copy of the working tree (that is,
           including only recorded changes).  If the test fails, you will be offered to abort the
           record operation.

           The  `--set-scripts-executable`  option  causes  scripts  to be made executable in the
           clean copy of the working tree, prior to running the test.  See `darcs clone`  for  an
           explanation of the script heuristic.

           If your test command is tediously slow (e.g. `make all`) and you are recording several
           patches in a row, you may wish to use `--no-test` to skip all but the final test.

           To see some context (unchanged lines) around each change, use the `--unified` option.

       darcs clone <repository> [<directory>]
           Clone creates a copy of a  repository.   The  optional  second  argument  specifies  a
           destination  directory  for  the  new copy; if omitted, it is inferred from the source
           location.

           By default Darcs will copy every patch from the original repository.   If  you  expect
           the  original  repository  to remain accessible, you can use `--lazy` to avoid copying
           patches until they are needed ('copy on demand').  This is  particularly  useful  when
           copying a remote repository with a long history that you don't care about.

           When  cloning  locally, Darcs automatically uses hard linking where possible.  As well
           as saving time and space, this enables to  move  or  delete  the  original  repository
           without  affecting  the  copy.   Hard  linking  requires  that the copy be on the same
           filesystem as the original repository, and that the filesystem support  hard  linking.
           This  includes  NTFS,  HFS+ and all general-purpose Unix filesystems (such as ext, UFS
           and ZFS). FAT does not support hard links.

           When cloning from a remote location, Darcs will look for  and  attempt  to  use  packs
           created by `darcs optimize http` in the remote repository.  Packs are single big files
           that can be downloaded faster than many little files.

           Darcs clone will not copy unrecorded changes to the source repository's working tree.

           You can copy a repository to a ssh url, in which case the new repository  will  always
           be complete.

           It  is often desirable to make a copy of a repository that excludes some patches.  For
           example, if releases are tagged then `darcs clone --tag .` would make a  copy  of  the
           repository as at the latest release.

           An  untagged repository state can still be identified unambiguously by a context file,
           as generated by `darcs log --context`.  Given the name of such a file, the `--context`
           option  will  create  a  repository  that includes only the patches from that context.
           When a user reports a bug in an unreleased version of your  project,  the  recommended
           way  to  find  out  exactly  what  version they were running is to have them include a
           context file in the bug report.

           You can also make a copy of an untagged state using the `--to-patch`  or  `--to-match`
           options,  which  exclude  patches  *after*  the  first  matching patch.  Because these
           options treat the set of patches as an ordered sequence, you may get different results
           after reordering with `darcs optimize reorder`.

           The  `--set-scripts-executable`  option  causes  scripts  to be made executable in the
           working tree. A script is any file that starts with a shebang ("#!").

       darcs pull [repository]...
           Pull is used to bring patches made in another repository into the  current  repository
           (that  is,  either  the  one  in  the current directory, or the one specified with the
           `--repodir` option). Pull accepts arguments, which are URLs from which  to  pull,  and
           when   called  without  an  argument,  pull  will  use  the  repository  specified  at
           `_darcs/prefs/defaultrepo`.

           The default (`--union`) behavior is to pull  any  patches  that  are  in  any  of  the
           specified  repositories.   If  you  specify the `--intersection` flag, darcs will only
           pull those patches which are present in all source repositories.  If you  specify  the
           `--complement` flag, darcs will only pull elements in the first repository that do not
           exist in any of the remaining repositories.

           If `--reorder` is supplied, the  set  of  patches  that  exist  only  in  the  current
           repository  is brought at the top of the current history. This will work even if there
           are no new patches to pull.

           See `darcs help apply` for detailed description of many options.

       darcs push [repository]
           Push is the opposite of pull.  Push allows  you  to  copy  patches  from  the  current
           repository into another repository.

           If  you  give  the  `--apply-as` flag, darcs will use `sudo` to apply the patches as a
           different user.  This can be useful if you want to set up a system where several users
           can  modify  the  same repository, but you don't want to allow them full write access.
           This isn't secure against skilled malicious attackers, but at least can  protect  your
           repository from clumsy, inept or lazy users.

           `darcs  push`  will compress the patch data before sending it to a remote location via
           ssh. This works as long as the remote darcs is not older than version 2.5. If you  get
           errors  that  indicate  a  corrupt  patch  bundle,  you  should  try  again  with  the
           `--no-compress` option.

   Preparing patches before recording:
       darcs move <source> ... <destination>
           Darcs cannot reliably distinguish between a file being deleted and a  new  one  added,
           and  a  file being moved.  Therefore Darcs always assumes the former, and provides the
           `darcs mv` command to let Darcs know when you want the latter.  This command will also
           move  the file in the working tree (unlike `darcs remove`), unless it has already been
           moved.

           Darcs will not rename a file if another file in the same folder  has  the  same  name,
           except  for  case.  The `--case-ok` option overrides this behaviour.  Windows and OS X
           usually use filesystems that do not allow files a folder to have the same name  except
           for case (for example, `ReadMe` and `README`).  If `--case-ok` is used, the repository
           might be unusable on those systems!

       darcs remove <file|directory> ...
           The `darcs remove` command exists primarily for symmetry  with  `darcs  add`,  as  the
           normal  way  to  remove  a  file  from version control is simply to delete it from the
           working tree.  This command is only useful in the unusual  case  where  one  wants  to
           record  a  removal  patch  WITHOUT deleting the copy in the working tree (which can be
           re-added).

           Note that applying a removal patch to a repository (e.g. by pulling  the  patch)  will
           ALWAYS affect the working tree of that repository.

       darcs replace <old> <new> <file> ...
           In  addition  to  line-based  patches,  Darcs  supports  a  limited  form  of  lexical
           substitution.  Files are treated as sequences of words, and each occurrence of the old
           word is replaced by the new word.  This is intended to provide a clean way to rename a
           function or variable.  Such renamings typically affect lines all  through  the  source
           code,  so  a  traditional line-based patch would be very likely to conflict with other
           branches, requiring manual merging.

           Files are tokenized according to one simple rule: words are  strings  of  valid  token
           characters, and everything between them (punctuation and whitespace) is discarded.  By
           default, valid  token  characters  are  letters,  numbers  and  the  underscore  (i.e.
           `[A-Za-z0-9_]`).   However  if  the  old  and/or new token contains either a hyphen or
           period, BOTH hyphen and period are treated as valid (i.e. `[A-Za-z0-9_.-]`).

           The set of valid characters can be customized using the `--token-chars`  option.   The
           argument  must  be  surrounded  by  square  brackets.   If a hyphen occurs between two
           characters in the set, it is treated as a set range.  For  example,  in  most  locales
           `[A-Z]`  denotes  all  uppercase  letters.   If  the first character is a caret, valid
           tokens are taken to be the complement  of  the  remaining  characters.   For  example,
           `[^:\n]`  could be used to match fields in the passwd(5), where records and fields are
           separated by newlines and colons respectively.

           If  you  choose  to  use  `--token-chars`,  you  are  STRONGLY  encouraged  to  do  so
           consistently.   The  consequences  of  using  multiple  replace patches with different
           `--token-chars` arguments on the same file are not well tested nor well understood.

           By default Darcs will refuse to perform a replacement if the new token is  already  in
           use,  because  the  replacements  would  be  not  be distinguishable from the existing
           tokens.  This behaviour can be overridden by supplying the `--force`  option,  but  an
           attempt to `darcs rollback` the resulting patch will affect these existing tokens.

           Limitations:

           The  tokenizer treats files as byte strings, so it is not possible for `--token-chars`
           to include multi-byte characters, such as the non-ASCII parts  of  UTF-8.   Similarly,
           trying  to  replace a "high-bit" character from a unibyte encoding will also result in
           replacement of the same byte in files with different encodings.  For example, an acute
           a from ISO 8859-1 will also match an alpha from ISO 8859-7.

           Due  to limitations in the patch file format, `--token-chars` arguments cannot contain
           literal whitespace.  For example, `[^ \n\t]` cannot be used to declare all  characters
           except  the  space,  tab  and  newline  as  valid within a word, because it contains a
           literal space.

           Unlike POSIX regex(7) bracket expressions, character classes (such  as  `[[:alnum:]]`)
           are  NOT supported by `--token-chars`, and will be silently treated as a simple set of
           characters.

   Querying the repository:
       darcs log [file|directory]...
           The `darcs log` command lists patches of the current repository or, with  `--repo`,  a
           remote repository.  Without options or arguments, ALL patches will be listed.

           When  given  files  or directories paths as arguments, only patches which affect those
           paths are listed.  This includes patches that happened to files before they were moved
           or renamed.

           When  given  `--from-tag`  or `--from-patch`, only patches since that tag or patch are
           listed.  Similarly, the `--to-tag` and `--to-patch` options restrict the list to older
           patches.

           The  `--last`  and `--max-count` options both limit the number of patches listed.  The
           former applies BEFORE other filters, whereas the latter applies AFTER  other  filters.
           For  example  `darcs  log  foo.c --max-count 3` will print the last three patches that
           affect foo.c, whereas `darcs log --last 3 foo.c` will,  of  the  last  three  patches,
           print only those that affect foo.c.

           Four  output formats exist.  The default is `--human-readable`. The slightly different
           `--machine-readable` format enables to see patch dependencies in non-interactive mode.
           You  can  also  select `--context`, which is an internal format that can be re-read by
           Darcs (e.g. `darcs clone --context`).

           Finally, there is `--xml-output`, which emits valid XML... unless a the patch metadata
           (author,  name  or  description)  contains a non-ASCII character and was recorded in a
           non-UTF8 locale.

       darcs annotate [file|directory]
           When `darcs annotate` is called on a file, it will find the patch that  last  modified
           each line in that file. This also works on directories.

           The   `--machine-readable`   option  can  be  used  to  generate  output  for  machine
           postprocessing.

       darcs diff [file|directory]...
           The `darcs diff` command compares two versions of the  working  tree  of  the  current
           repository.  Without options, the pristine (recorded) and unrecorded working trees are
           compared.  This is lower-level than the `darcs whatsnew` command, since it  outputs  a
           line-by-line  diff,  and  it is also slower.  As with `darcs whatsnew`, if you specify
           files or directories, changes to other files are not listed.  The command always  uses
           an external diff utility.

           With  the `--patch` option, the comparison will be made between working trees with and
           without that patch.  Patches *after* the selected patch are not present in  either  of
           the compared working trees.  The `--from-patch` and `--to-patch` options allow the set
           of patches in the `old' and `new' working trees to be specified separately.

           The associated tag and match options are also understood, e.g. `darcs diff  --from-tag
           1.0  --to-tag 1.1`.  All these options assume an ordering of the patch set, so results
           may be affected by operations such as `darcs optimize reorder`.

           diff(1) is called with the arguments `-rN`.  The `--unified` option causes `-u` to  be
           passed  to diff(1).  An additional argument can be passed using `--diff-opts`, such as
           `--diff-opts=-ud` or `--diff-opts=-wU9`.

           The `--diff-command` option can be used to specify an alternative  utility.  Arguments
           may be included, separated by whitespace.  The value is not interpreted by a shell, so
           shell constructs cannot be used.  The arguments %1 and %2 MUST be included, these  are
           substituted for the two working trees being compared. For instance:

               darcs diff -p . --diff-command "meld %1 %2"

           If this option is used, `--diff-opts` is ignored.

       darcs show contents [file]...
           Show  contents can be used to display an earlier version of some file(s).  If you give
           show contents no version arguments, it displays the recorded version of the file(s).

       darcs show dependencies
           The `darcs show dependencies` command is used to create a graph  of  the  dependencies
           between patches of the repository (by default up to last tag).

           The resulting graph is described in Dot Language, a general example of use could be:

           darcs show dependencies | dot -Tpdf -o FILE.pdf

       darcs show files [file|directory]...
           The  `darcs  show files` command lists those files and directories in the working tree
           that are under version control.  This command is primarily for scripting purposes; end
           users will probably want `darcs whatsnew --summary`.

           A  file is "pending" if it has been added but not recorded.  By default, pending files
           (and directories) are listed; the `--no-pending` option prevents this.

           By default `darcs show files` lists both files and directories, but  the  `--no-files`
           and `--no-directories` flags modify this behaviour.

           By default entries are one-per-line (i.e. newline separated).  This can cause problems
           if the files themselves contain newlines or other control characters.  To  get  around
           this,  the  `--null`  option uses the null character instead.  The script interpreting
           output from this command needs to understand this idiom; `xargs -0` is such a command.

           For example, to list version-controlled files by size:

               darcs show files -0 | xargs -0 ls -ldS

       darcs show index
           The `darcs show index` command lists  all  version-controlled  files  and  directories
           along  with their hashes as stored in `_darcs/index`. For files, the fields correspond
           to file size, sha256 of the current file content and the filename.
       darcs show pristine
           The `darcs show pristine` command lists all version-controlled files  and  directories
           along  with  the  hashes of their pristine copies. For files, the fields correspond to
           file size, sha256 of the pristine file content and the filename.
       darcs show repo
           The `darcs show repo`  command  displays  statistics  about  the  current  repository,
           allowing  third-party  scripts  to access this information without inspecting `_darcs`
           directly (and without breaking when the `_darcs` format changes).

           The 'Weak Hash' identifies the  set  of  patches  of  a  repository  independently  of
           ordering.  It  can be used to easily compare two repositories of a same project. It is
           not cryptographically secure.

           By default, output includes  statistics  that  require  walking  through  the  patches
           recorded  in the repository, namely the 'Weak Hash' and the count of patches.  If this
           data isn't needed, use `--no-enum-patches` to accelerate this  command  from  O(n)  to
           O(1).

           By  default,  output  is in a human-readable format.  The `--xml-output` option can be
           used to generate output for machine postprocessing.

       darcs show authors
           The `darcs show authors` command lists the authors of the current  repository,  sorted
           by  the  number  of  patches  contributed.   With the `--verbose` option, this command
           simply lists the author of each patch (without aggregation or sorting).

           An author's name or email address may change over time.  To tell Darcs  when  multiple
           author  strings refer to the same individual, create an `.authorspellings` file in the
           root of the working tree.  Each line in this file begins with  an  author's  canonical
           name  and  address,  and may be followed by a comma separated list of extended regular
           expressions.  Blank lines and lines beginning  with  two  hyphens  are  ignored.   The
           format of `.authorspelling` can be described by this pattern:

               name <address> [, regexp ]*

           There  are  some  pitfalls concerning special characters: Whitespaces are stripped, if
           you need space in regexp use [ ].  Because comma serves as a  separator  you  have  to
           escape  it  if you want it in regexp. Note that `.authorspelling` use extended regular
           expressions so +, ? and so on are metacharacters and you need to  escape  them  to  be
           interpreted literally.

           Any  patch  with  an  author  string  that matches the canonical address or any of the
           associated regexps is considered to be the work  of  that  author.   All  matching  is
           case-insensitive  and  partial  (it can match a substring). Use ^,$ to match the whole
           string in regexps

           Currently this canonicalization step is done only  in  `darcs  show  authors`.   Other
           commands, such as `darcs log` use author strings verbatim.

           An example `.authorspelling` file is:

               -- This is a comment.
               Fred Nurk <fred@example.com>
               John Snagge <snagge@bbc.co.uk>, John, snagge@, js@(si|mit).edu
               Chuck Jones\, Jr. <chuck@pobox.com>, cj\+user@example.com

       darcs show tags
           The tags command writes a list of all tags in the repository to standard output.

           Tab  characters  (ASCII  character  9)  in  tag names are changed to spaces for better
           interoperability with shell tools. A warning is printed if this happens.

       darcs show patch-index
           When given the `--verbose` flag, the command dumps the complete content of  the  patch
           index and checks its integrity.
       darcs test [[initialization] command]
           Run test on the current recorded state of the repository.  Given no arguments, it uses
           the default repository test (see `darcs setpref`).  Given one argument, it  treats  it
           as  a  test  command.  Given two arguments, the first is an initialization command and
           the second is the test (meaning the exit code of the first command is not  taken  into
           account  to  determine  success  of  the test).  If given the `--linear` or `--bisect`
           flags, it tries to find the most recent version in the repository which passes a test.

           `--linear` does linear search starting from head, and  moving  away  from  head.  This
           strategy  is  best when the test runs very quickly or the patch you're seeking is near
           the head.

           `--bisect` does binary search.  This strategy is best when the test runs  very  slowly
           or the patch you're seeking is likely to be in the repository's distant past.

           `--backoff`  starts  searching  from  head, skipping further and further into the past
           until the test succeeds.  It then does a binary search on a subset  of  those  skipped
           patches.   This  strategy  works  well  unless  the  patch  you're  seeking  is in the
           repository's distant past.

           Under the assumption that failure is monotonous, `--linear` and `--bisect` produce the
           same  result.   (Monotonous  means  that  when  moving away from head, the test result
           changes only once from "fail" to "ok".)  If failure is not monotonous, any one of  the
           patches that break the test is found at random.

   Undoing and correcting:
       darcs revert [file|directory]...
           The  `darcs  revert`  command  discards  unrecorded changes the working tree.  As with
           `darcs record`, you will be asked which hunks (changes) to revert.  The `--all` switch
           can  be  used  to  avoid  such prompting. If files or directories are specified, other
           parts of the working tree are not reverted.

           In you accidentally reverted something you wanted to keep (for example, typing  `darcs
           rev  -a`  instead  of  `darcs  rec  -a`),  you can immediately run `darcs unrevert` to
           restore it.  This is only guaranteed to work if the repository has not  changed  since
           `darcs revert` ran.

       darcs unrevert
           Unrevert is a rescue command in case you accidentally reverted something you wanted to
           keep (for example, typing `darcs rev -a` instead of `darcs rec -a`).

           This command may fail if the repository has  changed  since  the  revert  took  place.
           Darcs  will  ask  for  confirmation  before executing an interactive command that will
           DEFINITELY prevent unreversion.

       darcs amend [file|directory]...
           Amend updates a "draft" patch with additions or improvements, resulting  in  a  single
           "finished" patch.

           By  default `amend` proposes you to record additional changes.  If instead you want to
           remove changes, use the flag `--unrecord`.

           When recording a draft patch, it is a good idea to start the name with `DRAFT:`.  When
           done,  remove it with `darcs amend --edit-long-comment`.  Alternatively, to change the
           patch name without starting an editor, use the `--name`/`-m` flag:

               darcs amend --match 'name "DRAFT: foo"' --name 'foo2'

           Like `darcs record`, if you call amend with files as arguments, you will only be asked
           about  changes  to  those  files.   So  to amend a patch to foo.c with improvements in
           bar.c, you would run:

               darcs amend --match 'touch foo.c' bar.c

           It is usually a bad idea to amend another developer's patch.  To make amend  only  ask
           about  your  own  patches  by  default,  you can add something like `amend match David
           Roundy` to `~/.darcs/defaults`, where `David Roundy` is your name.

       darcs rebase pull [repository]...
           Copy and apply patches from another repository,  suspending  any  local  patches  that
           conflict.
       darcs rebase apply <patchfile>
           Apply a patch bundle, suspending any local patches that conflict.
       darcs rebase suspend
           Select patches to move into a suspended state at the end of the repo.

       darcs rebase unsuspend
           Selected patches to restore from a suspended state to the end of the repo.

       darcs rebase obliterate
           Obliterate a patch that is currently suspended.

       darcs rebase log
           List the currently suspended changes.

       darcs rollback [file|directory]...
           Rollback  is  used to undo the effects of some changes from patches in the repository.
           The selected changes are undone in your working  tree,  but  the  repository  is  left
           unchanged. First you are offered a choice of which patches to undo, then which changes
           within the patches to undo.

           Before doing `rollback`, you may want to temporarily undo the changes of your  working
           tree (if there are) and save them for later use.  To do so, you can run `revert`, then
           run `rollback`, record a patch, and run `unrevert` to restore the saved  changes  into
           your working tree.

       darcs unrecord
           Unrecord  does the opposite of record: it deletes patches from the repository, without
           changing the working tree.  Deleting patches from the repository makes active  changes
           again  which  you  may  record  or  revert later.  Beware that you should not use this
           command if there is a possibility that another user may have already pulled the patch.

       darcs obliterate
           Obliterate completely removes recorded patches from your local repository. The changes
           will  be undone in your working tree and the patches will not be shown in your changes
           list anymore. Beware that you can lose precious code by obliterating!

           One way to save obliterated patches is to use the -O flag.  A  patch  bundle  will  be
           created  locally,  that you will be able to apply later to your repository with `darcs
           apply`.

   Direct modification of the repository:
       darcs tag [tagname]
           The `darcs tag` command names the current repository state, so that it can  easily  be
           referred to later.  Every *important* state should be tagged; in particular it is good
           practice to tag each stable release with a number  or  codename.   Advice  on  release
           numbering can be found at <http://producingoss.com/en/development-cycle.html>.

           To reproduce the state of a repository `R` as at tag `t`, use the command `darcs clone
           --tag t R`.  The command `darcs show tags` lists all tags in the current repository.

           Tagging also provides significant performance benefits: when Darcs  reaches  a  shared
           tag that depends on all antecedent patches, it can simply stop processing.

           Like  normal  patches,  a  tag has a name, an author, a timestamp and an optional long
           description, but it does not change the working tree.  A tag can have any name, but it
           is generally best to pick a naming scheme and stick to it.

           By  default a tag names the entire repository state at the time the tag is created. If
           the --ask-deps option is used, the patches to include  as  part  of  the  tag  can  be
           explicitly selected.

           The  `darcs  tag`  command  accepts the `--pipe` option, which behaves as described in
           `darcs record`.

       darcs setpref <pref> <value>
           When working on project with multiple repositories and contributors, it  is  sometimes
           desirable  for  a preference to be set consistently project-wide.  This is achieved by
           treating a preference set with `darcs setpref` as an unrecorded change, which can then
           be recorded and then treated like any other patch.

           Valid preferences are:

           *  test  -- a shell command that runs regression tests * predist -- a shell command to
           run before `darcs dist' * boringfile -- the path to a version-controlled boring file *
           binariesfile -- the path to a version-controlled binaries file

           For  example,  a  project  using  GNU  autotools, with a `make test` target to perform
           regression tests, might enable Darcs' integrated regression testing with the following
           command:

               darcs setpref test 'autoconf && ./configure && make && make test'

           Note that merging is not currently implemented for preferences: if two patches attempt
           to set the same preference, the last patch applied to the repository will always  take
           precedence.   This  is  considered  a low-priority bug, because preferences are seldom
           set.

   Exchanging patches by e-mail:
       darcs send [repository]
           Send is used to prepare  a  bundle  of  patches  that  can  be  applied  to  a  target
           repository.   Send  accepts  the  URL  of  the repository as an argument.  When called
           without an argument, send will use the most recent repository that was  either  pushed
           to, pulled from or sent to.  By default, the patch bundle is saved to a file, although
           you may directly send it by mail.

           The `--output`, `--output-auto-name`, and `--to` flags determine what darcs does  with
           the  patch bundle after creating it.  If you provide an `--output` argument, the patch
           bundle is saved to that file.  If you specify `--output-auto-name`, the  patch  bundle
           is  saved  to  a  file  with an automatically generated name.  If you give one or more
           `--to` arguments, the bundle of patches is sent to those locations. The locations  may
           either be email addresses or urls that the patch should be submitted to via HTTP.

           If   you  provide  the  `--mail`  flag,  darcs  will  look  at  the  contents  of  the
           `_darcs/prefs/email` file in the target repository (if it exists), and send the  patch
           by  email  to  that  address.   In this case, you may use the `--cc` option to specify
           additional recipients without overriding the default repository email address.

           If `_darcs/prefs/post` exists in the target repository, darcs will upload to  the  URL
           contained  in that file, which may either be a `mailto:` URL, or an `http://` URL.  In
           the latter case, the patch is posted to that URL.

           If there is no email address associated with the repository, darcs will prompt you for
           an email address.

           Use  the  `--subject`  flag to set the subject of the e-mail to be sent.  If you don't
           provide a subject on the command line, darcs will make one up based on  names  of  the
           patches in the patch bundle.

           Use  the  `--in-reply-to`  flag  to  set the In-Reply-To and References headers of the
           e-mail to be sent. By default no additional headers are included so e-mail will not be
           treated as reply by mail readers.

           If  you want to include a description or explanation along with the bundle of patches,
           you need to specify the `--edit-description` flag, which will cause darcs to  open  up
           an editor with which you can compose a message to go along with your patches.

           If  you  want  to  use a command different from the default one for sending email, you
           need to specify a command line with the `--sendmail-command` option. The command  line
           can  contain  some format specifiers which are replaced by the actual values. Accepted
           format specifiers are `%s` for subject, `%t` for to, `%c` for cc, `%b` for the body of
           the  mail,  `%f`  for  from,  `%a`  for  the  patch  bundle and the same specifiers in
           uppercase for the URL-encoded values.  Additionally you can add `%<` to the end of the
           command line if the command expects the complete email message on standard input. E.g.
           the command lines for evolution and msmtp look like this:

               evolution "mailto:%T?subject=%S&attach=%A&cc=%C&body=%B"
               msmtp -t %<

           Do not confuse the `--author` options with the return address that `darcs  send`  will
           set for your patch bundle.

           For example, if you have two email addresses A and B:

           * If you use `--author A` but your machine is configured to send mail from
             address  B  by default, then the return address on your message will be B.  * If you
           use `--from A` and your mail client supports setting the
             From: address arbitrarily (some non-Unix-like mail clients, especially,
             may not support this), then the return address will be A; if it does
             not support this, then the return address will  be  B.   *  If  you  supply  neither
           `--from` nor `--author` then the return
             address will be B.

           In  addition, unless you specify the sendmail command with `--sendmail-command`, darcs
           sends email using the default email command on your computer. This default command  is
           determined  by  the  `configure` script. Thus, on some non-Unix-like OSes, `--from` is
           likely to not work at all.

       darcs apply <patchfile>
           The `darcs apply` command takes a patch bundle and attempts  to  insert  it  into  the
           current  repository.  In addition to invoking it directly on bundles created by `darcs
           send`, it is used internally by `darcs push` on the remote end of an SSH connection.

           If no file is supplied, the bundle is read from standard input.

           If given an email instead of a patch bundle, Darcs will look for the bundle as a  MIME
           attachment to that email.  Currently this will fail if the MIME boundary is rewritten,
           such as in Courier and Mail.app.

           If the `--reply noreply@example.net` option is used, and the bundle is attached to  an
           email,  Darcs  will send a report (indicating success or failure) to the sender of the
           bundle (the `To` field).  The argument to noreply  is  the  address  the  report  will
           appear to originate FROM.

           The  `--cc`  option  will  cause the report to be CC'd to another address, for example
           `--cc  reports@lists.example.net,admin@lists.example.net`.    Using   `--cc`   without
           `--reply` is undefined.

           If you want to use a command different from the default one for sending mail, you need
           to specify a command line with the `--sendmail-command` option.  The command line  can
           contain  the  format  specifier  `%t`  for  to  and you can add `%<` to the end of the
           command line if the command expects the complete mail on standard input. For  example,
           the command line for msmtp looks like this:

               msmtp -t %<

           If  gpg(1)  is  installed,  you  can use `--verify pubring.gpg` to reject bundles that
           aren't signed by a key in `pubring.gpg`.

           If `--test` is supplied and a test is defined (see `darcs setpref`), the  bundle  will
           be  rejected  if  the test fails after applying it.  In that case, the rejection email
           from `--reply` will include the test output.

           A patch bundle may introduce unresolved conflicts with existing patches  or  with  the
           working   tree.    By   default,   Darcs   will   add  conflict  markers  (see  `darcs
           mark-conflicts`).

           The `--external-merge` option lets you resolve these conflicts using an external merge
           tool.   In  the  option,  `%a` is replaced with the common ancestor (merge base), `%1`
           with the first version, `%2` with the second version, and `%o`  with  the  path  where
           your  resolved  content  should  go.  For example, to use the xxdiff visual merge tool
           you'd specify: `--external-merge='xxdiff -m -O -M %o %1 %a %2'`

           The `--allow-conflicts` option will skip conflict marking; this  is  useful  when  you
           want  to  treat  a  repository  as  just a bunch of patches, such as using `darcs pull
           --union` to download of your co-workers patches before going offline.

           This can mess up unrecorded changes in the working tree, forcing you  to  resolve  the
           conflict  immediately.   To simply reject bundles that introduce unresolved conflicts,
           using the `--dont-allow-conflicts` option.  Making  this  the  default  in  push-based
           workflows is strongly recommended.

           Unlike   most   Darcs   commands,   `darcs   apply`  defaults  to  `--all`.   Use  the
           `--interactive` option to pick which patches to apply from a bundle.

   Other commands:
       darcs optimize clean
           This command deletes obsolete files within the repository.
       darcs optimize http
           Using this  option  creates  'repository  packs'  that  could  dramatically  speed  up
           performance  when a user does a `darcs clone` of the repository over HTTP. To make use
           of packs, the clients must have a darcs of at least version 2.10.

       darcs optimize reorder
           This command moves recent patches (those not  included  in  the  latest  tag)  to  the
           "front",  reducing  the  amount  that  a typical remote command needs to download.  It
           should also reduce the CPU time needed for some operations.
       darcs optimize enable-patch-index
           Build the patch index, an internal data structure that accelerates commands that  need
           to know what patches touch a given file. Such as annotate and log.
       darcs optimize disable-patch-index
           Delete and stop maintaining the patch index from the repository.
       darcs optimize compress
           By  default  patches  are  compressed  with  zlib  (RFC  1951)  to reduce storage (and
           download)  size.   In  exceptional  circumstances,  it  may  be  preferable  to  avoid
           compression.   In this case the `--dont-compress` option can be used (e.g. with `darcs
           record`) to avoid compression.

           The `darcs optimize uncompress` and `darcs optimize compress` commands can be used  to
           ensure  existing  patches  in  the current repository are respectively uncompressed or
           compressed.
       darcs optimize uncompress
           By default patches are  compressed  with  zlib  (RFC  1951)  to  reduce  storage  (and
           download)  size.   In  exceptional  circumstances,  it  may  be  preferable  to  avoid
           compression.  In this case the `--dont-compress` option can be used (e.g. with  `darcs
           record`) to avoid compression.

           The  `darcs optimize uncompress` and `darcs optimize compress` commands can be used to
           ensure existing patches in the current repository  are  respectively  uncompressed  or
           compressed.
       darcs optimize relink
           The `darcs optimize relink` command hard-links patches that the current repository has
           in   common   with   its   peers.    Peers   are   those   repositories   listed    in
           `_darcs/prefs/sources`,  or  defined  with  the  `--sibling` option (which can be used
           multiple times).

           Darcs uses hard-links automatically, so this command is rarely  needed.   It  is  most
           useful  if  you  used `cp -r` instead of `darcs clone` to copy a repository, or if you
           pulled the same patch from a remote repository into multiple local repositories.
       darcs optimize pristine
           This command updates the format  of  `_darcs/pristine.hashed/`,  which  was  different
           before darcs 2.3.1.
       darcs optimize upgrade
           Convert old-fashioned repositories to the current default hashed format.
       darcs optimize cache <directory> ...
           This  command  deletes  obsolete  files within the global cache.  It takes one or more
           directories as arguments, and  recursively  searches  all  repositories  within  these
           directories.  Then  it  deletes  all  files in the global cache not belonging to these
           repositories.  When no directory is given, it searches repositories in the user's home
           directory.

           It also automatically migrates the global cache to the (default) bucketed format.

       darcs dist
           `darcs  dist`  creates  a  compressed  archive  in  the  repository's  root directory,
           containing the recorded state of the working tree (unrecorded changes and the `_darcs`
           directory  are  excluded).   The command accepts matchers to create an archive of some
           past repository state, for instance `--tag`.

           By default, the archive (and the top-level directory within the archive) has the  same
           name as the repository, but this can be overridden with the `--dist-name` option.

           If  a  predist  command  is set (see `darcs setpref`), that command will be run on the
           recorded state prior to archiving.  For example, autotools projects would  set  it  to
           `autoconf && automake`.

           If `--zip` is used, matchers and the predist command are ignored.

       darcs mark-conflicts [file|directory]...
           Darcs  requires  human  guidance  to  unify changes to the same part of a source file.
           When a conflict first occurs, darcs will add the initial state and both choices to the
           working  tree,  delimited  by  the  markers `v v v`, `=====`,  `* * *` and `^ ^ ^`, as
           follows:

               v v v v v v v
               Initial state.
               =============
               First choice.
               *************
               Second choice.
               ^ ^ ^ ^ ^ ^ ^

           However, you might revert or manually delete these markers without actually  resolving
           the  conflict.   In  this case, `darcs mark-conflicts` is useful to show where are the
           unresolved conflicts.  It is also useful if `darcs apply` or `darcs  pull`  is  called
           with `--allow-conflicts`, where conflicts aren't marked initially.

           Unless you use the `--dry-run` flag, any unrecorded changes to the affected files WILL
           be lost forever when you run this command!  You  will  be  prompted  for  confirmation
           before this takes place.

       darcs repair
           The  `darcs  repair`  command  attempts  to  fix corruption in the current repository.
           Currently it can only repair  damage  to  the  pristine  tree,  which  is  where  most
           corruption occurs.  This command rebuilds a pristine tree by applying successively the
           patches in the repository to an empty tree.

           The flag `--dry-run` make this operation read-only, making darcs  exit  unsuccessfully
           (with  a  non-zero  exit status) if the rebuilt pristine is different from the current
           pristine.

       darcs convert darcs-2 <source> [<destination>]
           This command converts a repository that uses the old patch semantics  `darcs-1`  to  a
           new repository with current `darcs-2` semantics.

           WARNING:  the  repository produced by this command is not understood by Darcs 1.x, and
           patches cannot be exchanged between repositories in darcs-1 and darcs-2 formats.

           Furthermore, repositories created by different invocations of this command SHOULD  NOT
           exchange patches.

       darcs convert export
           This command enables you to export darcs repositories into git.

           For a one-time export you can use the recipe:

               $ cd repo
               $ git init ../mirror
               $ darcs convert export | (cd ../mirror && git fast-import)

           For incremental export using marksfiles:

               $ cd repo
               $ git init ../mirror
               $ touch ../mirror/git.marks
               $ darcs convert export --read-marks darcs.marks --write-marks darcs.marks
                  |     (cd     ../mirror    &&    git    fast-import    --import-marks=git.marks
           --export-marks=git.marks)

           In the case of incremental export, be  careful  to  never  amend,  delete  or  reorder
           patches in the source darcs repository.

           Also,  be  aware  that  exporting  a darcs repo to git will not be exactly faithful in
           terms of history if the darcs repository contains conflicts.

           Limitations:

           * Empty directories  are  not  supported  by  the  fast-export  protocol.   *  Unicode
           filenames are currently not correctly handled.
             See http://bugs.darcs.net/issue2359 .

       darcs convert import [<directory>]
           This  command  imports  git repositories into new darcs repositories.  Further options
           are accepted (see `darcs help init`).

           To convert a git repo to a new darcs one you may run:
               $ (cd gitrepo && git fast-export --all -M) | darcs convert import darcsmirror

           WARNING: git repositories with branches will produce weird results,
                    use at your own risks.

           Incremental import with marksfiles is currently not supported.

       darcs fetch [repository]...
           Fetch is similar to `pull` except that it does not apply any patches  to  the  current
           repository.  Instead,  it  generates  a  patch  bundle  that  you can apply later with
           `apply`.

           Fetch's behaviour is essentially similar to pull's, so  please  consult  the  help  of
           `pull` to know more.

ENVIRONMENT

   HOME and APPDATA
       Per-user  preferences  are  set in $HOME/.darcs (on Unix) or %APPDATA%/darcs (on Windows).
       This is also the default location of the cache.

   DARCS_EDITOR, VISUAL, and EDITOR
       To edit a patch description of email comment, Darcs will invoke an external editor.   Your
       preferred  editor can be set as any of the environment variables $DARCS_EDITOR, $VISUAL or
       $EDITOR.  If none of these are set, nano is used.  If nano crashes or is not found in your
       PATH, vi, emacs, emacs -nw and (on Windows) edit are each tried in turn.

   DARCS_PAGER and PAGER
       Darcs  will  invoke  a  pager if the output of some command is longer than 20 lines. Darcs
       will use the pager specified by $DARCS_PAGER or $PAGER.  If neither are set,  `less`  will
       be used.

   DARCS_DONT_COLOR, DARCS_ALWAYS_COLOR, DARCS_ALTERNATIVE_COLOR, and DARCS_DO_COLOR_LINES
       If  the  terminal  understands  ANSI  color escape sequences, darcs will highlight certain
       keywords and delimiters when printing patches. This can  be  turned  off  by  setting  the
       environment  variable DARCS_DONT_COLOR to 1. If you use a pager that happens to understand
       ANSI colors, like `less -R`, darcs can be forced always to highlight the output by setting
       DARCS_ALWAYS_COLOR to 1. If you can't see colors you can set DARCS_ALTERNATIVE_COLOR to 1,
       and darcs will use ANSI codes for bold and reverse video instead of colors.  In  addition,
       there  is  an extra-colorful mode, which is not enabled by default, which can be activated
       with DARCS_DO_COLOR_LINES

   DARCS_DONT_ESCAPE_TRAILING_SPACES and DARCS_DONT_ESCAPE_TRAILING_CR
       By default darcs will escape (by highlighting if possible) any kind of spaces at  the  end
       of  lines  when  showing  patch  contents.   If you don't want this you can turn it off by
       setting DARCS_DONT_ESCAPE_TRAILING_SPACES to 1. A special case exists  for  only  carriage
       returns: DARCS_DONT_ESCAPE_TRAILING_CR

   DARCS_DONT_ESCAPE_ANYTHING,            DARCS_DONT_ESCAPE_EXTRA,            DARCS_ESCAPE_EXTRA,
       DARCS_DONT_ESCAPE_ISPRINT, and DARCS_ESCAPE_8BIT
       Darcs needs to escape certain characters when  printing  patch  contents  to  a  terminal,
       depending on the encoding specified in your locale setting.

       By  default,  darcs  assumes that your locale encoding is ASCII compatible.  This includes
       UTF-8 and some 8-bit encodings like ISO/IEC-8859 (including  its  variants).  Since  ASCII
       contains  control  characters like backspace (which could hide patch content from the user
       when printed literally to the terminal), and even ones that may introduce  security  risks
       such  as  redirecting  commands to the shell, darcs needs to escape such characters.  They
       are printed as `^<control letter>` or `\<hex code>`. Darcs also uses  special  markup  for
       line  endings that are preceeded by white space, since the white space would otherwise not
       be recognizable.

       If you use an encoding that is not ASCII compatible, things are somewhat less smooth. Such
       encodings include UTF-16 and UTF-32, as well as many of the encodings that became obsolete
       with unicode. In this case you have two options: you can set DARCS_DONT_ESCAPE_ANYTHING to
       1.  Then everything that doesn't flip code sets should work, and so will all the bells and
       whistles in your terminal. This environment variable can also be handy  if  you  pipe  the
       output  to  a  pager  or  external  filter that knows better than darcs how to handle your
       encoding. Note that all escaping, including  the  special  escaping  of  any  line  ending
       spaces, will be turned off by this setting.

       Another  possibility  is  to  explicitly tell darcs to not escape or escape certain bytes,
       using DARCS_DONT_ESCAPE_EXTRA and  DARCS_ESCAPE_EXTRA.  Their  values  should  be  strings
       consisting  of  the  verbatim  bytes  in question. The do-escapes take precedence over the
       dont-escapes. Space characters are still escaped  at  line  endings  though.  The  special
       environment  variable  DARCS_DONT_ESCAPE_TRAILING_CR turns off escaping of carriage return
       last on the line (DOS style).

       For   historical   reasons,   darcs   also    supports    DARCS_DONT_ESCAPE_ISPRINT    and
       DARCS_USE_ISPRINT  (which  are  synonyms).  These make sense only for 8-bit encodings like
       ISO-8859 and are no longer needed since nowadays  darcs  does  the  right  thing  here  by
       default.

       Finally,  if  you are in a highly security sensitive situation (or just paranoid for other
       reasons), you can set DARCS_ESCAPE_8BIT to 1.  This  will  cause  darcs  to  escape  every
       non-ASCII byte in addition to ASCII control characters.

   DARCS_TMPDIR and TMPDIR
       Darcs  often creates temporary directories.  For example, the `darcs diff` command creates
       two for the working trees to be diffed.  By default temporary directories are  created  in
       /tmp,  or  if  that  doesn't  exist,  in  _darcs  (within  the current repo).  This can be
       overridden by specifying some other directory  in  the  file  _darcs/prefs/tmpdir  or  the
       environment variable $DARCS_TMPDIR or $TMPDIR.

   DARCS_KEEP_TMPDIR
       If  the  environment  variable  DARCS_KEEP_TMPDIR  is  defined,  darcs will not remove the
       temporary directories it creates.  This is intended primarily for debugging Darcs  itself,
       but  it can also be useful, for example, to determine why your test preference (see `darcs
       setpref`) is failing when you run `darcs record`, but working when run manually.

   DARCS_EMAIL and EMAIL
       Each patch is attributed to its author, usually  by  email  address  (for  example,  `Fred
       Bloggs  <fred@example.net>`).   Darcs  looks in several places for this author string: the
       `--author`   option,   the   files   `_darcs/prefs/author`   (in   the   repository)   and
       `~/.darcs/author`  (in  your home directory), and the environment variables `$DARCS_EMAIL`
       and `$EMAIL`.  If none of those exist, Darcs will prompt you  for  an  author  string  and
       write it to `~/.darcs/author`.  Note that if you have more than one email address, you can
       put them all in `~/.darcs/author`, one author per line.  Darcs will still prompt  you  for
       an author, but it allows you to select from the list, or to type in an alternative.

   SENDMAIL
       On  Unix,  the  `darcs  send`  command relies on sendmail(8).  The `--sendmail-command` or
       $SENDMAIL environment variable can be used to provide an explicit path  to  this  program;
       otherwise the standard locations /usr/sbin/sendmail and /usr/lib/sendmail will be tried.

   DARCS_SLOPPY_LOCKS
       If on some filesystems you get an error of the kind:

           darcs: takeLock [...]: atomic_create [...]: unsupported operation

       you may want to try to export DARCS_SLOPPY_LOCKS=True.

   DARCS_SSH
       Repositories  of  the  form  [user@]host:[dir]  are taken to be remote repositories, which
       Darcs accesses with the external program ssh(1).

       The environment variable $DARCS_SSH can be used to  specify  an  alternative  SSH  client.
       Arguments  may  be  included,  separated by whitespace.  The value is not interpreted by a
       shell, so shell constructs cannot be used; in particular,  it  is  not  possible  for  the
       program name to contain whitespace by using quoting or escaping.

   DARCS_SCP and DARCS_SFTP
       When  reading from a remote repository, Darcs will attempt to run `darcs transfer-mode` on
       the remote host.  This will fail if the remote host only has Darcs  1  installed,  doesn't
       have Darcs installed at all, or only allows SFTP.

       If  transfer-mode fails, Darcs will fall back on scp(1) and sftp(1).  The commands invoked
       can be customized with the environment variables $DARCS_SCP and $DARCS_SFTP  respectively,
       which  behave  like  $DARCS_SSH.   If  the  remote  end  allows  only  sftp,  try  setting
       DARCS_SCP=sftp.

   SSH_PORT
       If this environment variable is set, it will be used as the port number for all SSH  calls
       made  by  Darcs (when accessing remote repositories over SSH).  This is useful if your SSH
       server does  not  run  on  the  default  port,  and  your  SSH  client  does  not  support
       ssh_config(5).    OpenSSH   users  will  probably  prefer  to  put  something  like  `Host
       *.example.net Port 443` into their ~/.ssh/config file.

   HTTP_PROXY, HTTPS_PROXY, FTP_PROXY, ALL_PROXY, and NO_PROXY
       If Darcs was built with libcurl, the environment  variables  HTTP_PROXY,  HTTPS_PROXY  and
       FTP_PROXY can be set to the URL of a proxy in the form

           [protocol://]<host>[:port]

       In  which  case  libcurl  will  use the proxy for the associated protocol (HTTP, HTTPS and
       FTP). The environment variable ALL_PROXY can be used to set a single proxy for all libcurl
       requests.

       If  the  environment  variable NO_PROXY is a comma-separated list of host names, access to
       those hosts will bypass proxies defined by the above variables. For example, it  is  quite
       common to avoid proxying requests to machines on the local network with

           NO_PROXY=localhost,*.localdomain

       For  compatibility  with  lynx et al, lowercase equivalents of these environment variables
       (e.g. $http_proxy) are also understood  and  are  used  in  preference  to  the  uppercase
       versions.

       If Darcs was not built with libcurl, all these environment variables are silently ignored,
       and there is no way to use a web proxy.

   DARCS_PROXYUSERPWD
       If  Darcs  was  built  with  libcurl,  and  you  are  using  a  web  proxy  that  requires
       authentication,  you  can set the $DARCS_PROXYUSERPWD environment variable to the username
       and password expected by the proxy, separated by a colon.  This  environment  variable  is
       silently ignored if Darcs was not built with libcurl.

   DARCS_CONNECTION_TIMEOUT
       Set  the maximum time in seconds that darcs allows and connection to take. If the variable
       is not specified the default are 30 seconds.  This option only works with curl.

FILES

   _darcs/prefs/motd
       The `_darcs/prefs/motd` file may contain a 'message of the day' which will be displayed to
       users who clone or pull from the repository without the `--quiet` option.

   _darcs/prefs/email
       The  `_darcs/prefs/email`  file  is used to provide the e-mail address for your repository
       that others will use when they `darcs send` a patch back to you. The contents of the  file
       should simply be an e-mail address.

   _darcs/prefs/post
       If  `_darcs/prefs/post`  exists in the target repository, `darcs send ` will upload to the
       URL contained in that file, which may either be a `mailto:` URL, or an `http://`  URL.  In
       the latter case, the patch is posted to that URL.

   _darcs/prefs/author
       The  `_darcs/prefs/author`  file  contains  the  email address (or name) to be used as the
       author  when   patches   are   recorded   in   this   repository,   e.g.   `David   Roundy
       <droundy@abridgegame.org>`.  This file overrides the contents of the environment variables
       `$DARCS_EMAIL` and `$EMAIL`.

   _darcs/prefs/defaults
       Default values for darcs commands. Each line of this file has the following form:

           COMMAND FLAG VALUE

       where `COMMAND` is either the name of the command to which the default applies,  or  `ALL`
       to  indicate that the default applies to all commands accepting that flag. The `FLAG` term
       is the name of the long argument option without  the  `--`,  i.e.  `verbose`  rather  than
       `--verbose`.   Finally,  the  `VALUE` option can be omitted if the flag does not involve a
       value. If the value has spaces in it, use single quotes, not double  quotes,  to  surround
       it.  Each  line only takes one flag. To set multiple defaults for the same command (or for
       `ALL` commands), use multiple lines.

       Note that the use of  `ALL`  easily  can  have  unpredicted  consequences,  especially  if
       commands  in newer versions of darcs accepts flags that they did not in previous versions.
       Only use safe flags with `ALL`.

       For example, if your system clock is bizarre, you could instruct darcs  to  always  ignore
       the file modification times by adding the following line:

           ALL ignore-times

       There  are  some  options which are meant specifically for use in `_darcs/prefs/defaults`.
       One of them is `--disable`. As the name suggests, this option will disable  every  command
       that  got it as argument. So, if you are afraid that you could damage your repositories by
       inadvertent use of a command like amend, add the following line:

           amend disable

       Also, a global preferences file can be created with the  name  `.darcs/defaults`  in  your
       home directory. Options present there will be added to the repository-specific preferences
       if they do not conflict.

   _darcs/prefs/sources
       The `_darcs/prefs/sources` file is used to indicate alternative locations  from  which  to
       download patches. This file contains lines such as:

           cache:/home/droundy/.cache/darcs
           readonly:/home/otheruser/.cache/darcs
           repo:http://darcs.net

       This  would  indicate  that  darcs  should  first look in `/home/droundy/.cache/darcs` for
       patches that might be missing, and if the patch is not there, it should save a copy  there
       for future use.  In that case, darcs will look in `/home/otheruser/.cache/darcs` to see if
       that user might have downloaded a copy, but will not try to save a copy there, of  course.
       Finally,  it  will look in `http://darcs.net`. Note that the `sources` file can also exist
       in `~/.darcs/`. Also note that the sources mentioned in your `sources` file will be  tried
       *before*  the  repository you are pulling from. This can be useful in avoiding downloading
       patches multiple times when you pull from a remote  repository  to  more  than  one  local
       repository.

       A  global  cache  is  enabled by default in your home directory. The cache allows darcs to
       avoid re-downloading patches (for example, when doing a second darcs  clone  of  the  same
       repository), and also allows darcs to use hard links to reduce disk usage.

       Note  that  the cache directory should reside on the same filesystem as your repositories,
       so you may need to vary this. You can also use multiple  cache  directories  on  different
       filesystems, if you have several filesystems on which you use darcs.

   _darcs/prefs/boring
       The `_darcs/prefs/boring` file may contain a list of regular expressions describing files,
       such as object files, that you do not expect to add  to  your  project.  A  newly  created
       repository  has a boring file that includes many common source control, backup, temporary,
       and compiled files.

       You may want to have the boring file under version control. To do this you can  use  darcs
       setpref to set the value 'boringfile' to the name of your desired boring file (e.g. `darcs
       setpref boringfile .boring`, where `.boring` is the repository path of  a  file  that  has
       been   darcs   added   to   your   repository).   The   boringfile   preference  overrides
       `_darcs/prefs/boring`, so be sure to copy that file to the boringfile.

       You  can  also  set  up  a  'boring'  regexps  file  in   your   home   directory,   named
       `~/.darcs/boring`, which will be used with all of your darcs repositories.

       Any  file not already managed by darcs and whose repository path matches any of the boring
       regular expressions is considered boring. The boring file is  used  to  filter  the  files
       provided  to  darcs  add, to allow you to use a simple `darcs add newdir newdir/*` without
       accidentally adding a bunch of object files. It is also used  when  the  `--look-for-adds`
       flag  is given to whatsnew or record. Note that once a file has been added to darcs, it is
       not considered boring, even if it matches the boring file filter.

   _darcs/prefs/binaries
       The `_darcs/prefs/binaries` file may contain a  list  of  regular  expressions  describing
       files  that  should be treated as binary files rather than text files. Darcs automatically
       treats files containing characters `^Z` or `NULL` within the first  4096  bytes  as  being
       binary files.  You probably will want to have the binaries file under version control.  To
       do this you can use `darcs setpref` to set the value 'binariesfile' to the  name  of  your
       desired binaries file (e.g. `darcs setpref binariesfile ./.binaries`, where `.binaries` is
       a file that has been darcs added to your repository). As with the  boring  file,  you  can
       also set up a `~/.darcs/binaries` file if you like.

   _darcs/prefs/defaultrepo
       Contains  the URL of the default remote repository used by commands `pull`, `push`, `send`
       and  `optimize  relink`.  Darcs  edits  this  file  automatically   or   when   the   flag
       `--set-default` is used.

   _darcs/prefs/tmpdir
       By  default  temporary  directories  are  created  in `/tmp`, or if that doesn't exist, in
       `_darcs` (within the current repo).  This can  be  overridden  by  specifying  some  other
       directory in the file `_darcs/prefs/tmpdir` or the environment variable `$DARCS_TMPDIR` or
       `$TMPDIR`.

   _darcs/prefs/prefs
       Contains the preferences set by the command `darcs setprefs`.  Do not edit manually.

BUGS

       At http://bugs.darcs.net/ you can find a list of known bugs in Darcs.  Unknown bugs can be
       reported  at  that  site  (after  creating  an  account)  or  by  emailing  the  report to
       bugs@darcs.net.

SEE ALSO

       The Darcs website  provides  a  lot  of  additional  information.   It  can  be  found  at
       http://darcs.net/

LICENSE

       Darcs  is  free  software; you can redistribute it and/or modify it under the terms of the
       GNU General Public License as published by the Free Software Foundation; either version 2,
       or (at your option) any later version.

                                         2.14.2 (release)                                DARCS(1)