DARCS(1)

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.