focal (1) darcs.1.gz

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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)