Next: Best practices Up: Darcs User Manual Previous: Getting started Contents
There are several ways you can adjust darcs' behavior to suit your needs.
The first is to edit files in the _darcs/prefs/ directory of a
repository. Such configuration only applies when working with that
repository. To configure darcs on a per-user rather than per-repository
basis (but with essentially the same methods), you can edit (or create)
files in the ~/.darcs/ directory.
Finally, the behavior of some darcs commands can be modified by setting
appropriate environment variables.
The global darcs directory is %APPDATA%\darcs\. This typically expands to
C:\Documents And Settings\user\Application Data\darcs\.
This folder contains the cache, as well as all the per-user
settings files: preferences, boring etc... These will became the new defaults
that can be overridden on per-repository basis.
The _darcs directory contains a prefs directory. This
directory exists simply to hold user configuration settings specific to
this repository. The contents of this directory are intended to be
modifiable by the user, although in some cases a mistake in such a
modification may cause darcs to behave strangely.
Default values for darcs commands can be configured on a per-repository
basis by editing (and possibly creating) the _darcs/prefs/defaults
file. Each line of this file has the following form:
COMMAND FLAG VALUEwhere
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 is one such as verbose that doesn't 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
didn't in previous versions. A command like obliterate could be
devastating with the ``wrong'' flags (for example -all). Only use safe
flags with ALL.
~/.darcs/defaults |
provides defaults for this user account
(for MS Windows, see ![[*]](./crossref.png) ) |
repo/_darcs/prefs/defaults |
provides defaults for one project, |
| overrules changes per user |
For example, if your system clock is bizarre, you could instruct darcs to
always ignore the file modification times by adding the following line to
your _darcs/prefs/defaults file. (Note that this would have to be
done for each repository!)
ALL ignore-times
If you never want to run a test when recording to a particular repository
(but still want to do so when running
check on that repository), and like to name
all your patches ``Stupid patch'', you could use the following:
record no-test record patch-name Stupid patch
If you would like a command to be run every time patches are recorded in a particular repository (for example if you have one central repository, that all developers contribute to), then you can set apply to always run a command when apply is successful. For example, if you need to make sure that the files in the repository have the correct access rights you might use the following. There are two things to note about using darcs this way:
darcs add; doing so would
allow people to modify that file and then run arbitrary scripts on
your main repository, possibly damaging or violating security.
apply posthook chmod -R a+r * apply run-posthook
Similarly, if you need a command to run automatically before darcs performs an action you can use a prehook. Using prehooks it could be possible to canonicalize line endings before recording patches.
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-record, add the following line to
_darcs/prefs/defaults:
amend-record disable
Also, a global preferences file can be created with the name
.darcs/defaults in your home directory, on MS Windows .
Options present there will be added to the repository-specific preferences.
If they conflict with repository-specific options, the repository-specific
ones will take precedence.
_darcs/prefs/repos file contains a list of repositories you have
pulled from or pushed to, and is used for autocompletion of pull and push
commands in bash. Feel free to delete any lines from this list that might
get in there, or to delete the file as a whole.
_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 $EMAIL.
_darcs/prefs/boring file may contain a list of regular
expressions describing files, such as object files, that you do not expect
to add to your project. As an example, you could have:
\.hi$ \.o$ ^\.[^/] ^_ ~$ (^|/)CVS($|/)A newly created repository has a longer 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,
(see on MS Windows), which will be
used with all of your darcs repositories.
Any file not already managed by darcs and whose repository path (such
as manual/index.html) 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 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
^Z\ or '\0' 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
(see on MS Windows).
_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/sources file is used to indicate alternative
locations from which to download patches when using a ``hashed''
repository. This file contains lines such as:
cache:/home/droundy/.darcs/cache readonly:/home/otheruser/.darcs/cache repo:http://darcs.netThis would indicate that darcs should first look in
/home/droundy/.darcs/cache for patches that might be missing, and if
the patch isn't there, it should save a copy there for future use. In that
case, darcs will look in /home/otheruser/.darcs/cache to see if that
user might have downloaded a copy, but won't 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 get 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/motd file may contain a ``message of the day''
which will be displayed to users who get or pull from the repository without the
--quiet option.
There are a few environment variables whose contents affect darcs' behavior. Here is a quick list of all the variables and their documentation in the rest of the manual:
| Variable | Section |
|---|---|
| DARCS_EDITOR, EDITOR, VISUAL | |
| DARCS_PAGER, PAGER | |
| HOME | |
| TERM | |
| DARCS_EMAIL, EMAIL | |
| DARCS_APPLY_FOO | |
| DARCS_GET_FOO | |
| DARCS_MGET_FOO | |
| DARCS_MGETMAX | |
| DARCS_PROXYUSERPWD | |
| DARCS_CONNECTION_TIMEOUT | |
| DARCS_SSH | |
| DARCS_SCP | |
| DARCS_SFTP | |
| SSH_PORT | |
| DARCS_ALTERNATIVE_COLOR | |
| DARCS_ALWAYS_COLOR | |
| DARCS_DO_COLOR_LINES | |
| DARCS_DONT_COLOR | |
| DARCS_DONT_ESCAPE_TRAILING_CR | |
| DARCS_DONT_ESCAPE_TRAILING_SPACES | |
| DARCS_DONT_ESCAPE_8BIT | |
| DARCS_DONT_ESCAPE_ANYTHING | |
| DARCS_DONT_ESCAPE_ISPRINT | |
| DARCS_ESCAPE_EXTRA | |
| DARCS_DONT_ESCAPE_EXTRA | |
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.
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.
[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.
This method overrides all other ways of getting foo://xxx URLs.
Note that each command should be constructed so that it sends the downloaded content to STDOUT, and the next argument to it should be the URL. Here are some examples that should work for DARCS_GET_HTTP:
fetch -q -o - curl -s -f lynx -source wget -q -O -
Apart from such toy examples, it is likely that you will need to manipulate the argument before passing it to the actual fetcher program. For example, consider the problem of getting read access to a repository on a CIFS (SMB) share without mount privileges:
export DARCS_GET_SMB="smbclient -c get" darcs get smb://fs/twb/Desktop/hello-world
The above command will not work for several reasons. Firstly, Darcs will pass it an argument beginning with `smb:', which smbclient does not understand. Secondly, the host and share `//fs/twb' must be presented as a separate argument to the path `Desktop/hello-world'. Thirdly, smbclient requires that `get' and the path be a single argument (including a space), rather than two separate arguments. Finally, smbclient's `get' command writes the file to disk, while Darcs expects it to be printed to standard output.
In principle, we could get around such problems by making the variable contain a shell script, e.g.
export DARCS_GET_SMB='sh -c "...; smbclient $x -c \"get $y\""'
Unfortunately, Darcs splits the command on whitespace and does not understand that quotation or escaping, so there is no way to make Darcs pass the text after `-c' to sh as a single argument. Therefore, we instead need to put such one-liners in separate, executable scripts.
Continuing our smbclient example, we create an executable script
~/.darcs/libexec/get_smb with the following contents:
#!/bin/bash -e
IFS=/ read host share file <<<"${1#smb://}"
smbclient //$host/$share -c "get $file -"
And at last we can say
export DARCS_GET_SMB=~/.darcs/libexec/get_smb darcs get smb://fs/twb/Desktop/hello-world
If set, DARCS_MGET_FOO will be used to fetch many files from a single repository simultaneously. Replace FOO and foo as appropriate to handle other URL schemes. These commands are not interpreted by a shell, so you cannot use shell metacharacters, and the first word in the command must be the name of an executable located in your path. The GET command will be called with a URL for each file. The MGET command will be invoked with a number of URLs and is expected to download the files to the current directory, preserving the file name but not the path. The APPLY command will be called with a darcs patchfile piped into its standard input. Example:
wget -q
These commands are not interpreted by a shell, so you cannot use shell meta-characters.
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.
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 needs to escape certain characters when printing patch contents to a terminal. Characters like backspace can otherwise hide patch content from the user, and other character sequences can even in some cases redirect commands to the shell if the terminal allows it.
By default darcs will only allow printable 7-bit ASCII characters (including space),
and the two control characters tab and newline.
(See the last paragraph in this section for a way to tailor this behavior.)
All other octets are printed in quoted form (as ^<control letter> or
\<hex code>).
Darcs has some limited support for locales. If the system's locale is a single-byte character encoding, like the Latin encodings, you can set the environment variable DARCS_DONT_ESCAPE_ISPRINT to 1 and darcs will display all the printables in the current system locale instead of just the ASCII ones. NOTE: This curently does not work on some architectures if darcs is compiled with GHC 6.4 or later. Some non-ASCII control characters might be printed and can possibly spoof the terminal.
For multi-byte character encodings things are less smooth. UTF-8 will work if you set DARCS_DONT_ESCAPE_8BIT to 1, but non-printables outside the 7-bit ASCII range are no longer escaped. E.g., the extra control characters from Latin-1 might leave your terminal at the mercy of the patch contents. Space characters outside the 7-bit ASCII range are no longer recognized and will not be properly escaped at line endings.
As a last resort 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.
There are two environment variables you can set to explicitly tell darcs to not escape or escape octets. They are DARCS_DONT_ESCAPE_EXTRA and DARCS_ESCAPE_EXTRA. Their values should be strings consisting of the verbatim octets 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).
darcs-unstable 2012-06-20