Ubuntu Manpage: darcs - an advanced revision control system

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 edit
       darcs rebase obliterate
       darcs rebase log
       darcs rebase upgrade
       darcs rollback [file|directory]...
       darcs unrecord
       darcs obliterate
       darcs clean [file|directory]...
       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 upgrade
       darcs optimize cache
       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

       Unlike  conventional  revision control systems, Darcs is based on tracking changes, rather
       than versions: it can and does automatically re-order  independent  changes  when  needed.
       This  means that in Darcs the state of a repository should be regarded as a set of patches
       rather than a sequence of versions.

       Another distinguishing feature of darcs is that most commands are interactive by  default.
       For  instance, `darcs record' (the equivalent of what is usually called `commit') presents
       you with each unrecorded change and asks you whether it should be included in the patch to
       be  recorded.  Similarly,  `darcs  push'  and  `darcs  pull'  present you with each patch,
       allowing you to select which patches to push or pull.

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-hash and --to-hash are synonyms for
--from-match='hash...' and --to-match='hash...'
sensible combinations of --from-* and --to-* options are possible:
`darcs log --from-patch='html.*docu' --to-match='date 20040212'`
`darcs log --from-hash=368089c6969 --to-patch='^fix.*renamed or moved.$'`

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.

Existing files and subdirectories are not touched. You can record them with `darcs
record --look-for-adds`.

Initialize is commonly abbreviated to `init`.

Darcs currently supports three kinds of patch semantics. These are called `darcs-1`,
`darcs-2`, and `darcs-3`. They are mutually incompatible, that is, you cannot exchange
patches between repos with different semantics.

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.

The `darcs-3` semantics is EXPERIMENTAL and new in version 2.16. It is included only
as a technology preview and we do NOT recommend to use it for any serious work. The
on-disk format is not yet finalized and we cannot and will not promise that later
releases will work with darcs-3 repos created with any darcs version before 3.0.

Initialize and clone commands create the preferences files in _darcs/prefs/ directory
of the newly created repository. With option --with-prefs-templates `boring` and
`binaries` preferences files will be filled with default templates. If you want to
leave these files empty use --no-prefs-templates option. If you prefer to keep the
relevant settings globally, it will be convenient to add 'ALL no-prefs-templates' to
your ~/darcs/defaults file.

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 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 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.
WithSummary 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
conflicts with a change in an earlier patch. The phrase `duplicated`
means the change is identical to a change in an earlier 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. (This option
has no effect in interactive mode.) To view changes in conventional `diff` format, use
the `darcs diff` command; but note that `darcs diff` cannot properly display changes
when file renames are involved.

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 ("#!").

The --inherit-default option is meant to support a work flow where you have different
branches of the same upstream repository and want all your branches to have the same
upstream repo as the defaultrepo. It is most useful when enabled globally by adding
'ALL --inherit-default' to your ~/darcs/defaults file.

For the clone command it means the following: If the source repository already has a
defaultrepo set (either because you cloned it or because you explicitly used the
--set-default option), and both source and target are locally valid paths on the same
host, then the target repo will get the same defaultrepo as the source repo. Otherwise
the target repo gets the source repo itself as defaultrepo, i.e. we fall back to the
defalt behavior (--no-inherit-default).

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.

For the commands push, pull, and send it means the following: Changes the meaning of
the --set-default option so that it sets the (local) defaultrepo to the defaultrepo of
the remote repo, instead of the remote repo itself. This happens only if the remote
repo does have a defaultrepo set and both local and remote repositories are locally
valid paths on the same host, otherwise fall back to the default behavior (--no-
inherit-default).

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.

The --reorder-patches option works in the same way as it does for pull and apply:
instead of placing the new patches (coming from your local repository) on top of (i.e.
after) the existing (remote) ones, it puts the remote-only patches on top of the ones
that you are pushing. This can be useful, for instance, if you have recorded a tag
locally and want this tag to be clean in the remote repository after pushing.

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, `[^:0` 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, `[^ ]` 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 always called with the arguments `-rN` and by default also with `-u` to
show the differences in unified format. This can be turned off by passing `--no-
unified`. 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 subcommand
Display various information about a repository. See description of the subcommands for
details.

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
This command creates a graph of the dependencies between patches. The output format is
the Dot Language, see https://www.graphviz.org/doc/info/lang.html. The resulting graph
is transitively reduced, in other words, it contains only the direct dependencies, not
the indirect ones.

By default all patches in your repository are considered. You can limit this to a
range of patches using patch matching options, see `darcs help patterns` and the
options avaiable for this command. For instance, to visualize the dependencies between
all patches since the last tag, do:

darcs show dependencies --from-tag=. | dot -Tpdf -o FILE.pdf

This command can take a very(!) long time to compute its result, depending on the
number of patches in the selected range. For N patches it needs to do on the order of
N^3 commutations in the worst case.

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.

If the test command returns an exit code of 125, the repository state is treated as
"untestable" - for example you might get it to do this for a build break or other
result that isn't the actual problem you want to track down. This can lead to multiple
patches being reported as the source of the failure.

For example, if patch 1 introduces a build break, patch 2 breaks a test in an
unrelated bit of the code, and patch 3 fixes the build break, then patches 1,2 and 3
would be identified as causing the failure.

The `--shrink-failures` option, on by default, adds a post-processing step to reorder
patches to try to narrow down a failure more precisely. In the example above, it's
likely that patch 2 could be moved before patch 1 or after patch 3, allowing it to be
identified as the sole cause of the failure.

This shrinking can be disabled with `--no-shrink-failures`.

Undoing and correcting:
darcs revert [file|directory]...
The `darcs revert` command discards unrecorded changes in 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

Note that this command edits the history of your repo. It is primarily intended to be
used on patches that you authored yourself and did not yet publish. Using it for
patches that are already published, or even ones you did not author yourself, may
cause confusion and can disrupt your own and other people's work-flow. This depends a
lot on how your project is organized, though, so there may be valid exceptions to this
rule.

Using the `--not-in-remote` option is a good way to guard against accidentally editing
published patches. Without arguments, this deselects any patches that are also present
in the `defaultrepo`. If you work in a clone of some publically hosted repository,
then your `defaultrepo` will be that public repo. You can also give the option an
argument which is a path or URL of some other repository; you can use the option
multiple times with different repositories, which has the effect of treating all of
them as "upstream", that is, it prevents you from selecting a patch that is contained
in any of these repos.

You can also guard only against editing another developer's patch by using an
appropriate `--match` option with the `author` keyword. For instance, you could add
something like `<cmd> match Your Name` to your `~/.darcs/defaults`.

darcs rebase subcommand
The `darcs rebase' command is used to edit a collection of darcs patches.

The basic idea is that you can suspend patches from the end of a repository. These
patches are no longer part of the history and have no effect on the working tree.
Suspended patches are invisible to commands that access the repository from the
outside, such as push, pull, clone, send, etc.

The sequence of suspended patches can be manipulated in ways that are not allowed for
normal patches. For instance, `darcs rebase obliterate` allows you to remove a patch
in this sequence, even if other suspended patches depend on it. These other patches
will as a result become conflicted.

You can also operate on the normal patches in the usual way. If you add or remove
normal patches, the suspended patches will be automatically adapted to still apply to
the pristine state, possibly becoming conflicted in the course.

Note that as soon as a patch gets suspended, it will irrevocably loose its identity.
This means that suspending a patch is subject to the usual warnings about editing the
history of your project.

The opposite of suspending a patch is to unsuspend it. This turns it back into a
normal patch. If the patch is conflicted as a result of previous operations on either
the normal patches or the suspended patches, unsuspending will create appropriate
conflict markup. Note, however, that the unsuspended patch itself WILL NOT BE
CONFLICTED itself. This means that there is no way to re-generate the conflict markup.
Once you removed it, by editing files or using `darcs revert`, any information about
the conflict is lost.

As long as you have suspended patches, darcs will display a short message after each
command to remind you that your patch editing operation is still in progress.

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
Select suspended patches to restore to the end of the repo.

darcs rebase edit
Edit suspended patches.

darcs rebase obliterate
Obliterate a patch that is currently suspended.

darcs rebase log
List the currently suspended changes.

darcs rebase upgrade
Upgrade a repo with an old-style rebase in progress.

Doing this means you won't be able to use darcs version < 2.15 with this repository
until the rebase is finished.

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. The changes are now again visible with `darcs whatsnew` and
you can record or revert them as you please.

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`. See `darcs send` for a more detailed description.

darcs clean [file|directory]...
Remove unrecorded changes from the working tree.

This is an alias for `darcs revert -l/--look-for-adds` which means it works also on
files that have not been added. You can additionally pass `--boring` to get rid of
*every* unrecorded file or directory.

See description of `darcs revert` for more details.

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. It does so by recording a special kind of patch that makes no
changes and which explicitly depends on all patches currently existing in the
repository (except for those which are depended upon by other tags already in the
repository). In the common case of a sequential series of tags, this means that the
tag depends on all patches since the last tag, plus that tag itself.

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`. Note however that tags are matched as regular expressions, like with
`--patch`. To make sure you get the right tag it may be better to use `darcs clone
--tag '^t$'`. The command `darcs show tags` lists all tags in the current repository.

Tagging also provides significant performance benefits: when Darcs reaches a tag that
depends on all preceding patches, it can often stop processing. A tag in such a
position is called "clean". For instance, operations like push and pull need to
examine only patches that come after the latest shared clean tag.

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 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.

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

A patch bundle may introduce unresolved conflicts with existing patches or with the
working tree. By default, Darcs will refuse to apply conflicting patches (`--no-allow-
conflicts`).

The `--mark-conflicts` option instructs Darcs to allow conflicts and try to add
conflict markup in your working tree. Note that this may (partly) fail, because some
conflicts cannot be marked, such as e.g. conflicts between two adds of the same file.
In this case Darcs will warn you and display the conflicting changes instead. When
Darcs detects conflicts with unrecorded changes, it will give you an extra warning and
prompts you to confirm that you want to continue. This is because your original
unrecorded changes cannot be automatically restored by Darcs.

Note that conflict markup is something Darcs adds to your working tree files.
Nevertheless, you can always re-construct it using `darcs mark-conflicts`.

The `--external-merge` option lets you resolve 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 allows conflicts but does not add conflict markup.
This is useful when you want to treat a repository as just a bunch of patches, such as
using `darcs pull --union` to download all of your co-workers' patches before going
offline. Again, conflict markup can be added at any time later on using `darcs mark-
conflicts`.

For more information on conflicts in Darcs and how to resolve them, see the help on
`darcs mark-conflicts`.

Other commands:
darcs optimize subcommand
The `darcs optimize` command modifies internal data structures of the current
repository in an attempt to reduce its resource requirements.

For further details see the descriptions of the subcommands.

darcs optimize clean
Darcs normally does not delete hashed files that are no longer referenced by the
current repository state. This command can be use to get rid of these files to save
some disk space.

darcs optimize http
Using this option creates 'repository packs' that can 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. This is the behavior with
--shallow which is the default.

With the --deep option it tries to optimize all tags in the whole repository. This
breaks the history of patches into smaller bunches, which can further improve
efficiency, but requires all patches to be present. It is therefore less suitable for
lazy clones.

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
Patches, inventories, and pristine files are compressed with zlib (RFC 1951) to reduce
storage (and download) size. Older darcs versions allowed to store them uncompressed,
and darcs is still able to read those files if they are not compressed.

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
Patches, inventories, and pristine files are compressed with zlib (RFC 1951) to reduce
storage (and download) size. Older darcs versions allowed to store them uncompressed,
and darcs is still able to read those files if they are not compressed.

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 upgrade
Convert old-fashioned repositories to the current default hashed format.

darcs optimize cache
This command deletes obsolete files within the global cache.

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 reconcile independent changes to the same part of a
file. When a conflict first occurs, darcs will add the initial state and all
conflicting 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
*************
...more choices...
*************
last choice
^ ^ ^ ^ ^ ^ ^

If you happened to revert or manually delete this conflict markup without actually
resolving the conflict, `darcs mark-conflicts` can be used to re-create it; and
similarly if you have used `darcs apply` or `darcs pull` with `--allow-conflicts`,
where conflicts aren't marked initially.

In Darcs, a conflict counts as resolved when all of the changes involved in the
conflict (which can be more than two) are depended on by one or more later patches. If
you record a resolution for a particular conflict, `darcs mark-conflicts` will no
longer mark it, indicating that it is resolved. If you have unrecorded changes, these
count as (potential) conflict resolutions, too, just as if you had already recorded
them.

This principle extends to explicit "semantic" dependencies. For instance, recording a
tag will automatically mark all conflicts as resolved.

In the above schematic example the "initial state" corresponds to the recorded state
of the file in your repository. That is to say, the recorded effect of a conflict is
to apply none of the conflicting changes. This is usually not a state you would regard
as a successful resolution of the conflict; but there are exceptional situations where
this may be exactly what you want. In order to tell Darcs that you want this conflict
to be regarded as resolved, use `darcs record --ask-deps` to record a patch that
explicitly depends on all patches involved in the conflict.

darcs repair
The `darcs repair` command attempts to fix corruption in the current repository. It
works by successively applying all patches in the repository to an empty tree, each
time checking that the patch can be cleanly applied to the current pristine tree. If
we detect a problem, we try to repair the patch. Finally we compare the existing
pristine with the newly reconstructed one and if they differ, replace the existing
one. Any problem encountered is reported. The flag `--dry-run` makes this operation
read-only and causes it to exit unsuccessfully (with a non-zero exit status) in case
any problems are enountered.

darcs convert subcommand
Convert repositories between various formats.

See description of the subcommands for details.

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. Also,
you should not exchange patches between repositories created by different invocations
of this command. This means: - Before doing this conversion, you should merge into
this repo any patches
existing elsewhere that you might want to merge in future, so that they
will remain mergeable. (You can always remove them again after converting). - After
converting, you should tell everyone with a fork of this repo
to discard it and make a new fork of the converted repo.

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. Set $DARCS_PAGER - or $PAGER if the former is not set - to the empty string in
order not to use a pager.

DARCS_DONT_COLOR, DARCS_ALWAYS_COLOR, and DARCS_ALTERNATIVE_COLOR
If the terminal understands ANSI color escape sequences, darcs will highlight certain
keywords and delimiters when printing patches, and also print hunk lines in color
according to whether they are removed or added. 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.

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.

scp is also used by `darcs clone` if the destination is a remote ssh directory. This
operation can be made quite a bit faster by setting DARCS_SCP=rsync.

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.

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 options 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 with or without the `--`, i.e. `verbose` or
`--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.

Options listed in the defaults file are just that: defaults. You can override any default
on the command line.

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

A global defaults file can be created with the name `.darcs/defaults` in your home
directory. In case of conflicts, the defaults for a specific repository take precedence.

_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/sources
Besides the defaultrepo, darcs also keeps track of any other locations used in commands
for exchanging patches (e.g. push, pull, send). These are subsequently used as
alternatives from which to download patches. The file contains lines such as:

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

The prefix `cache:` indicates that darcs can use this as a read-write cache for patches,
`read-only:` indicates a cache that is only readable, and `repo:` denotes a (possibly
remote) repository. The order of the entries is immaterial: darcs will always try local
paths before remote ones, and only local ones will be used as potentially writable.

A global cache is enabled by default in your home directory under `.cache/darcs` (older
versions of darcs used `.darcs/cache` for this), or `$XDG_CACHE_HOME/darcs` if the
environment variable is set, see https://specifications.freedesktop.org/basedir-
spec/basedir-spec-latest.html. 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.

While darcs automatically adds entries to `_darcs/prefs/sources`, it does not currently
remove them. If one or more of the entries aren't accessible (e.g. because they resided on
a removable media), then darcs will bugger you with a hint, suggesting you remove those
entries. This is done because certain systems have extremely long timeouts associated with
some remotely accessible media (e.g. NFS over automounter on Linux), which can slow down
darcs operations considerably. On the other hand, when you clone a repo with --lazy from a
no longer accessible location, then the hint may give you an idea where the patches could
be found, so you can try to restore access to them.

_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.

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.

                                         2.18.4 (release)                                DARCS(1)