Configuration Files

    The Mercurial system uses a set of configuration files to control aspects
    of its behavior.

    The configuration files use a simple ini-file format. A configuration file
    consists of sections, led by a "[section]" header and followed by "name =
    value" entries:

      [ui]
      username = Firstname Lastname <firstname.lastname@example.net>
      verbose = True

    The above entries will be referred to as "ui.username" and "ui.verbose",
    respectively. See the Syntax section below.

    Files
    -----

    Mercurial reads configuration data from several files, if they exist.
    These files do not exist by default and you will have to create the
    appropriate configuration files yourself: global configuration like the
    username setting is typically put into "%USERPROFILE%\mercurial.ini" or
    "$HOME/.hgrc" and local configuration is put into the per-repository
    "<repo>/.hg/hgrc" file.

    The names of these files depend on the system on which Mercurial is
    installed. "*.rc" files from a single directory are read in alphabetical
    order, later ones overriding earlier ones. Where multiple paths are given
    below, settings from earlier paths override later ones.

    (Unix, Windows) "<repo>/.hg/hgrc"

        Per-repository configuration options that only apply in a particular
        repository. This file is not version-controlled, and will not get
        transferred during a "clone" operation. Options in this file override
        options in all other configuration files. On Unix, most of this file
        will be ignored if it doesn't belong to a trusted user or to a trusted
        group. See the documentation for the "[trusted]" section below for
        more details.

    (Unix) "$HOME/.hgrc"
    (Windows) "%USERPROFILE%\.hgrc"
    (Windows) "%USERPROFILE%\Mercurial.ini"
    (Windows) "%HOME%\.hgrc"
    (Windows) "%HOME%\Mercurial.ini"

        Per-user configuration file(s), for the user running Mercurial. On
        Windows 9x, "%HOME%" is replaced by "%APPDATA%". Options in these
        files apply to all Mercurial commands executed by this user in any
        directory. Options in these files override per-system and per-
        installation options.

    (Unix) "/etc/mercurial/hgrc"
    (Unix) "/etc/mercurial/hgrc.d/*.rc"

        Per-system configuration files, for the system on which Mercurial is
        running. Options in these files apply to all Mercurial commands
        executed by any user in any directory. Options in these files override
        per-installation options.

    (Unix) "<install-root>/etc/mercurial/hgrc"
    (Unix) "<install-root>/etc/mercurial/hgrc.d/*.rc"

        Per-installation configuration files, searched for in the directory
        where Mercurial is installed. "<install-root>" is the parent directory
        of the **hg** executable (or symlink) being run. For example, if
        installed in "/shared/tools/bin/hg", Mercurial will look in
        "/shared/tools/etc/mercurial/hgrc". Options in these files apply to
        all Mercurial commands executed by any user in any directory.

    (Windows) "<install-dir>\Mercurial.ini" **or**
    (Windows) "<install-dir>\hgrc.d\*.rc" **or**
    (Windows) "HKEY_LOCAL_MACHINE\SOFTWARE\Mercurial"

        Per-installation/system configuration files, for the system on which
        Mercurial is running. Options in these files apply to all Mercurial
        commands executed by any user in any directory. Registry keys contain
        PATH-like strings, every part of which must reference a
        "Mercurial.ini" file or be a directory where "*.rc" files will be
        read.  Mercurial checks each of these locations in the specified order
        until one or more configuration files are detected.  If the pywin32
        extensions are not installed, Mercurial will only look for site-wide
        configuration in "C:\Mercurial\Mercurial.ini".

    Syntax
    ------

    A configuration file consists of sections, led by a "[section]" header and
    followed by "name = value" entries (sometimes called "configuration
    keys"):

      [spam]
      eggs=ham
      green=
         eggs

    Each line contains one entry. If the lines that follow are indented, they
    are treated as continuations of that entry. Leading whitespace is removed
    from values. Empty lines are skipped. Lines beginning with "#" or ";" are
    ignored and may be used to provide comments.

    Configuration keys can be set multiple times, in which case Mercurial will
    use the value that was configured last. As an example:

      [spam]
      eggs=large
      ham=serrano
      eggs=small

    This would set the configuration key named "eggs" to "small".

    It is also possible to define a section multiple times. A section can be
    redefined on the same and/or on different configuration files. For
    example:

      [foo]
      eggs=large
      ham=serrano
      eggs=small

      [bar]
      eggs=ham
      green=
         eggs

      [foo]
      ham=prosciutto
      eggs=medium
      bread=toasted

    This would set the "eggs", "ham", and "bread" configuration keys of the
    "foo" section to "medium", "prosciutto", and "toasted", respectively. As
    you can see there only thing that matters is the last value that was set
    for each of the configuration keys.

    If a configuration key is set multiple times in different configuration
    files the final value will depend on the order in which the different
    configuration files are read, with settings from earlier paths overriding
    later ones as described on the "Files" section above.

    A line of the form "%include file" will include "file" into the current
    configuration file. The inclusion is recursive, which means that included
    files can include other files. Filenames are relative to the configuration
    file in which the "%include" directive is found. Environment variables and
    "~user" constructs are expanded in "file". This lets you do something
    like:

      %include ~/.hgrc.d/$HOST.rc

    to include a different configuration file on each computer you use.

    A line with "%unset name" will remove "name" from the current section, if
    it has been set previously.

    The values are either free-form text strings, lists of text strings, or
    Boolean values. Boolean values can be set to true using any of "1", "yes",
    "true", or "on" and to false using "0", "no", "false", or "off" (all case
    insensitive).

    List values are separated by whitespace or comma, except when values are
    placed in double quotation marks:

      allow_read = "John Doe, PhD", brian, betty

    Quotation marks can be escaped by prefixing them with a backslash. Only
    quotation marks at the beginning of a word is counted as a quotation
    (e.g., "foo"bar baz" is the list of "foo"bar" and "baz").

    Sections
    --------

    This section describes the different sections that may appear in a
    Mercurial configuration file, the purpose of each section, its possible
    keys, and their possible values.

    "alias"
    """""""

    Defines command aliases. Aliases allow you to define your own commands in
    terms of other commands (or aliases), optionally including arguments.
    Positional arguments in the form of "$1", "$2", etc in the alias
    definition are expanded by Mercurial before execution. Positional
    arguments not already used by "$N" in the definition are put at the end of
    the command to be executed.

    Alias definitions consist of lines of the form:

      <alias> = <command> [<argument>]...

    For example, this definition:

      latest = log --limit 5

    creates a new command "latest" that shows only the five most recent
    changesets. You can define subsequent aliases using earlier ones:

      stable5 = latest -b stable

    Note:
       It is possible to create aliases with the same names as existing
       commands, which will then override the original definitions. This is
       almost always a bad idea!

    An alias can start with an exclamation point ("!") to make it a shell
    alias. A shell alias is executed with the shell and will let you run
    arbitrary commands. As an example,

      echo = !echo

    will let you do "hg echo foo" to have "foo" printed in your terminal. A
    better example might be:

      purge = !$HG status --no-status --unknown -0 | xargs -0 rm

    which will make "hg purge" delete all unknown files in the repository in
    the same manner as the purge extension.

    Shell aliases are executed in an environment where "$HG" expand to the
    path of the Mercurial that was used to execute the alias. This is useful
    when you want to call further Mercurial commands in a shell alias, as was
    done above for the purge alias. In addition, "$HG_ARGS" expand to the
    arguments given to Mercurial. In the "hg echo foo" call above, "$HG_ARGS"
    would expand to "echo foo".

    Note:
       Some global configuration options such as "-R" are processed before
       shell aliases and will thus not be passed to aliases.

    "annotate"
    """"""""""

    Settings used when displaying file annotations. All values are Booleans
    and default to False. See "diff" section for related options for the diff
    command.

    "ignorews"
        Ignore white space when comparing lines.

    "ignorewsamount"
        Ignore changes in the amount of white space.

    "ignoreblanklines"
        Ignore changes whose lines are all blank.

    "auth"
    """"""

    Authentication credentials for HTTP authentication. This section allows
    you to store usernames and passwords for use when logging *into* HTTP
    servers. See the "[web]" configuration section if you want to configure
    *who* can login to your HTTP server.

    Each line has the following format:

      <name>.<argument> = <value>

    where "<name>" is used to group arguments into authentication entries.
    Example:

      foo.prefix = hg.intevation.org/mercurial
      foo.username = foo
      foo.password = bar
      foo.schemes = http https

      bar.prefix = secure.example.org
      bar.key = path/to/file.key
      bar.cert = path/to/file.cert
      bar.schemes = https

    Supported arguments:

    "prefix"
        Either "*" or a URI prefix with or without the scheme part. The
        authentication entry with the longest matching prefix is used (where
        "*" matches everything and counts as a match of length 1). If the
        prefix doesn't include a scheme, the match is performed against the
        URI with its scheme stripped as well, and the schemes argument, q.v.,
        is then subsequently consulted.

    "username"
        Optional. Username to authenticate with. If not given, and the remote
        site requires basic or digest authentication, the user will be
        prompted for it. Environment variables are expanded in the username
        letting you do "foo.username = $USER". If the URI includes a username,
        only "[auth]" entries with a matching username or without a username
        will be considered.

    "password"
        Optional. Password to authenticate with. If not given, and the remote
        site requires basic or digest authentication, the user will be
        prompted for it.

    "key"
        Optional. PEM encoded client certificate key file. Environment
        variables are expanded in the filename.

    "cert"
        Optional. PEM encoded client certificate chain file. Environment
        variables are expanded in the filename.

    "schemes"
        Optional. Space separated list of URI schemes to use this
        authentication entry with. Only used if the prefix doesn't include a
        scheme. Supported schemes are http and https. They will match static-
        http and static-https respectively, as well. Default: https.

    If no suitable authentication entry is found, the user is prompted for
    credentials as usual if required by the remote.

    "decode/encode"
    """""""""""""""

    Filters for transforming files on checkout/checkin. This would typically
    be used for newline processing or other localization/canonicalization of
    files.

    Filters consist of a filter pattern followed by a filter command. Filter
    patterns are globs by default, rooted at the repository root. For example,
    to match any file ending in ".txt" in the root directory only, use the
    pattern "*.txt". To match any file ending in ".c" anywhere in the
    repository, use the pattern "**.c". For each file only the first matching
    filter applies.

    The filter command can start with a specifier, either "pipe:" or
    "tempfile:". If no specifier is given, "pipe:" is used by default.

    A "pipe:" command must accept data on stdin and return the transformed
    data on stdout.

    Pipe example:

      [encode]
      # uncompress gzip files on checkin to improve delta compression
      # note: not necessarily a good idea, just an example
      *.gz = pipe: gunzip

      [decode]
      # recompress gzip files when writing them to the working dir (we
      # can safely omit "pipe:", because it's the default)
      *.gz = gzip

    A "tempfile:" command is a template. The string "INFILE" is replaced with
    the name of a temporary file that contains the data to be filtered by the
    command. The string "OUTFILE" is replaced with the name of an empty
    temporary file, where the filtered data must be written by the command.

    Note:
       The tempfile mechanism is recommended for Windows systems, where the
       standard shell I/O redirection operators often have strange effects and
       may corrupt the contents of your files.

    This filter mechanism is used internally by the "eol" extension to
    translate line ending characters between Windows (CRLF) and Unix (LF)
    format. We suggest you use the "eol" extension for convenience.

    "defaults"
    """"""""""

    (defaults are deprecated. Don't use them. Use aliases instead)

    Use the "[defaults]" section to define command defaults, i.e. the default
    options/arguments to pass to the specified commands.

    The following example makes "hg log" run in verbose mode, and "hg status"
    show only the modified files, by default:

      [defaults]
      log = -v
      status = -m

    The actual commands, instead of their aliases, must be used when defining
    command defaults. The command defaults will also be applied to the aliases
    of the commands defined.

    "diff"
    """"""

    Settings used when displaying diffs. Everything except for "unified" is a
    Boolean and defaults to False. See "annotate" section for related options
    for the annotate command.

    "git"
        Use git extended diff format.

    "nodates"
        Don't include dates in diff headers.

    "showfunc"
        Show which function each change is in.

    "ignorews"
        Ignore white space when comparing lines.

    "ignorewsamount"
        Ignore changes in the amount of white space.

    "ignoreblanklines"
        Ignore changes whose lines are all blank.

    "unified"
        Number of lines of context to show.

    "email"
    """""""

    Settings for extensions that send email messages.

    "from"
        Optional. Email address to use in "From" header and SMTP envelope of
        outgoing messages.

    "to"
        Optional. Comma-separated list of recipients' email addresses.

    "cc"
        Optional. Comma-separated list of carbon copy recipients' email
        addresses.

    "bcc"
        Optional. Comma-separated list of blind carbon copy recipients' email
        addresses.

    "method"
        Optional. Method to use to send email messages. If value is "smtp"
        (default), use SMTP (see the "[smtp]" section for configuration).
        Otherwise, use as name of program to run that acts like sendmail
        (takes "-f" option for sender, list of recipients on command line,
        message on stdin). Normally, setting this to "sendmail" or
        "/usr/sbin/sendmail" is enough to use sendmail to send messages.

    "charsets"
        Optional. Comma-separated list of character sets considered convenient
        for recipients. Addresses, headers, and parts not containing patches
        of outgoing messages will be encoded in the first character set to
        which conversion from local encoding ("$HGENCODING",
        "ui.fallbackencoding") succeeds. If correct conversion fails, the text
        in question is sent as is. Defaults to empty (explicit) list.

        Order of outgoing email character sets:

        1. "us-ascii": always first, regardless of settings
        2. "email.charsets": in order given by user
        3. "ui.fallbackencoding": if not in email.charsets
        4. "$HGENCODING": if not in email.charsets
        5. "utf-8": always last, regardless of settings

    Email example:

      [email]
      from = Joseph User <joe.user@example.com>
      method = /usr/sbin/sendmail
      # charsets for western Europeans
      # us-ascii, utf-8 omitted, as they are tried first and last
      charsets = iso-8859-1, iso-8859-15, windows-1252

    "extensions"
    """"""""""""

    Mercurial has an extension mechanism for adding new features. To enable an
    extension, create an entry for it in this section.

    If you know that the extension is already in Python's search path, you can
    give the name of the module, followed by "=", with nothing after the "=".

    Otherwise, give a name that you choose, followed by "=", followed by the
    path to the ".py" file (including the file name extension) that defines
    the extension.

    To explicitly disable an extension that is enabled in an hgrc of broader
    scope, prepend its path with "!", as in "foo = !/ext/path" or "foo = !"
    when path is not supplied.

    Example for "~/.hgrc":

      [extensions]
      # (the mq extension will get loaded from Mercurial's path)
      mq =
      # (this extension will get loaded from the file specified)
      myfeature = ~/.hgext/myfeature.py

    "hostfingerprints"
    """"""""""""""""""

    Fingerprints of the certificates of known HTTPS servers. A HTTPS
    connection to a server with a fingerprint configured here will only
    succeed if the servers certificate matches the fingerprint. This is very
    similar to how ssh known hosts works. The fingerprint is the SHA-1 hash
    value of the DER encoded certificate. The CA chain and web.cacerts is not
    used for servers with a fingerprint.

    For example:

      [hostfingerprints]
      hg.intevation.org = 38:76:52:7c:87:26:9a:8f:4a:f8:d3:de:08:45:3b:ea:d6:4b:ee:cc

    This feature is only supported when using Python 2.6 or later.

    "format"
    """"""""

    "usestore"
        Enable or disable the "store" repository format which improves
        compatibility with systems that fold case or otherwise mangle
        filenames. Enabled by default. Disabling this option will allow you to
        store longer filenames in some situations at the expense of
        compatibility and ensures that the on-disk format of newly created
        repositories will be compatible with Mercurial before version 0.9.4.

    "usefncache"
        Enable or disable the "fncache" repository format which enhances the
        "store" repository format (which has to be enabled to use fncache) to
        allow longer filenames and avoids using Windows reserved names, e.g.
        "nul". Enabled by default. Disabling this option ensures that the on-
        disk format of newly created repositories will be compatible with
        Mercurial before version 1.1.

    "dotencode"
        Enable or disable the "dotencode" repository format which enhances the
        "fncache" repository format (which has to be enabled to use dotencode)
        to avoid issues with filenames starting with ._ on Mac OS X and spaces
        on Windows. Enabled by default. Disabling this option ensures that the
        on-disk format of newly created repositories will be compatible with
        Mercurial before version 1.7.

    "merge-patterns"
    """"""""""""""""

    This section specifies merge tools to associate with particular file
    patterns. Tools matched here will take precedence over the default merge
    tool. Patterns are globs by default, rooted at the repository root.

    Example:

      [merge-patterns]
      **.c = kdiff3
      **.jpg = myimgmerge

    "merge-tools"
    """""""""""""

    This section configures external merge tools to use for file-level merges.

    Example "~/.hgrc":

      [merge-tools]
      # Override stock tool location
      kdiff3.executable = ~/bin/kdiff3
      # Specify command line
      kdiff3.args = $base $local $other -o $output
      # Give higher priority
      kdiff3.priority = 1

      # Define new tool
      myHtmlTool.args = -m $local $other $base $output
      myHtmlTool.regkey = Software\FooSoftware\HtmlMerge
      myHtmlTool.priority = 1

    Supported arguments:

    "priority"
      The priority in which to evaluate this tool. Default: 0.

    "executable"
      Either just the name of the executable or its pathname.  On Windows, the
      path can use environment variables with ${ProgramFiles} syntax. Default:
      the tool name.

    "args"
      The arguments to pass to the tool executable. You can refer to the files
      being merged as well as the output file through these variables:
      "$base", "$local", "$other", "$output". Default: "$local $base $other"

    "premerge"
      Attempt to run internal non-interactive 3-way merge tool before
      launching external tool.  Options are "true", "false", or "keep" to
      leave markers in the file if the premerge fails. Default: True

    "binary"
      This tool can merge binary files. Defaults to False, unless tool was
      selected by file pattern match.

    "symlink"
      This tool can merge symlinks. Defaults to False, even if tool was
      selected by file pattern match.

    "check"
      A list of merge success-checking options:

      "changed"
        Ask whether merge was successful when the merged file shows no
        changes.

      "conflicts"
        Check whether there are conflicts even though the tool reported
        success.

      "prompt"
        Always prompt for merge success, regardless of success reported by
        tool.

    "checkchanged"
      True is equivalent to "check = changed". Default: False

    "checkconflicts"
      True is equivalent to "check = conflicts". Default: False

    "fixeol"
      Attempt to fix up EOL changes caused by the merge tool. Default: False

    "gui"
      This tool requires a graphical interface to run. Default: False

    "regkey"
      Windows registry key which describes install location of this tool.
      Mercurial will search for this key first under "HKEY_CURRENT_USER" and
      then under "HKEY_LOCAL_MACHINE". Default: None

    "regkeyalt"
      An alternate Windows registry key to try if the first key is not found.
      The alternate key uses the same "regname" and "regappend" semantics of
      the primary key.  The most common use for this key is to search for
      32bit applications on 64bit operating systems. Default: None

    "regname"
      Name of value to read from specified registry key. Defaults to the
      unnamed (default) value.

    "regappend"
      String to append to the value read from the registry, typically the
      executable name of the tool. Default: None

    "hooks"
    """""""

    Commands or Python functions that get automatically executed by various
    actions such as starting or finishing a commit. Multiple hooks can be run
    for the same action by appending a suffix to the action. Overriding a
    site-wide hook can be done by changing its value or setting it to an empty
    string.  Hooks can be prioritized by adding a prefix of "priority" to the
    hook name on a new line and setting the priority.  The default priority is
    0 if not specified.

    Example ".hg/hgrc":

      [hooks]
      # update working directory after adding changesets
      changegroup.update = hg update
      # do not use the site-wide hook
      incoming =
      incoming.email = /my/email/hook
      incoming.autobuild = /my/build/hook
      # force autobuild hook to run before other incoming hooks
      priority.incoming.autobuild = 1

    Most hooks are run with environment variables set that give useful
    additional information. For each hook below, the environment variables it
    is passed are listed with names of the form "$HG_foo".

    "changegroup"
      Run after a changegroup has been added via push, pull or unbundle. ID of
      the first new changeset is in "$HG_NODE". URL from which changes came is
      in "$HG_URL".

    "commit"
      Run after a changeset has been created in the local repository. ID of
      the newly created changeset is in "$HG_NODE". Parent changeset IDs are
      in "$HG_PARENT1" and "$HG_PARENT2".

    "incoming"
      Run after a changeset has been pulled, pushed, or unbundled into the
      local repository. The ID of the newly arrived changeset is in
      "$HG_NODE". URL that was source of changes came is in "$HG_URL".

    "outgoing"
      Run after sending changes from local repository to another. ID of first
      changeset sent is in "$HG_NODE". Source of operation is in "$HG_SOURCE";
      see "preoutgoing" hook for description.

    "post-<command>"
      Run after successful invocations of the associated command. The contents
      of the command line are passed as "$HG_ARGS" and the result code in
      "$HG_RESULT". Parsed command line arguments are passed as "$HG_PATS" and
      "$HG_OPTS". These contain string representations of the python data
      internally passed to <command>. "$HG_OPTS" is a dictionary of options
      (with unspecified options set to their defaults). "$HG_PATS" is a list
      of arguments. Hook failure is ignored.

    "pre-<command>"
      Run before executing the associated command. The contents of the command
      line are passed as "$HG_ARGS". Parsed command line arguments are passed
      as "$HG_PATS" and "$HG_OPTS". These contain string representations of
      the data internally passed to <command>. "$HG_OPTS" is a  dictionary of
      options (with unspecified options set to their defaults). "$HG_PATS" is
      a list of arguments. If the hook returns failure, the command doesn't
      execute and Mercurial returns the failure code.

    "prechangegroup"
      Run before a changegroup is added via push, pull or unbundle. Exit
      status 0 allows the changegroup to proceed. Non-zero status will cause
      the push, pull or unbundle to fail. URL from which changes will come is
      in "$HG_URL".

    "precommit"
      Run before starting a local commit. Exit status 0 allows the commit to
      proceed. Non-zero status will cause the commit to fail. Parent changeset
      IDs are in "$HG_PARENT1" and "$HG_PARENT2".

    "prelistkeys"
      Run before listing pushkeys (like bookmarks) in the repository. Non-zero
      status will cause failure. The key namespace is in "$HG_NAMESPACE".

    "preoutgoing"
      Run before collecting changes to send from the local repository to
      another. Non-zero status will cause failure. This lets you prevent pull
      over HTTP or SSH. Also prevents against local pull, push (outbound) or
      bundle commands, but not effective, since you can just copy files
      instead then. Source of operation is in "$HG_SOURCE". If "serve",
      operation is happening on behalf of remote SSH or HTTP repository. If
      "push", "pull" or "bundle", operation is happening on behalf of
      repository on same system.

    "prepushkey"
      Run before a pushkey (like a bookmark) is added to the repository. Non-
      zero status will cause the key to be rejected. The key namespace is in
      "$HG_NAMESPACE", the key is in "$HG_KEY", the old value (if any) is in
      "$HG_OLD", and the new value is in "$HG_NEW".

    "pretag"
      Run before creating a tag. Exit status 0 allows the tag to be created.
      Non-zero status will cause the tag to fail. ID of changeset to tag is in
      "$HG_NODE". Name of tag is in "$HG_TAG". Tag is local if "$HG_LOCAL=1",
      in repository if "$HG_LOCAL=0".

    "pretxnchangegroup"
      Run after a changegroup has been added via push, pull or unbundle, but
      before the transaction has been committed. Changegroup is visible to
      hook program. This lets you validate incoming changes before accepting
      them. Passed the ID of the first new changeset in "$HG_NODE". Exit
      status 0 allows the transaction to commit. Non-zero status will cause
      the transaction to be rolled back and the push, pull or unbundle will
      fail. URL that was source of changes is in "$HG_URL".

    "pretxncommit"
      Run after a changeset has been created but the transaction not yet
      committed. Changeset is visible to hook program. This lets you validate
      commit message and changes. Exit status 0 allows the commit to proceed.
      Non-zero status will cause the transaction to be rolled back. ID of
      changeset is in "$HG_NODE". Parent changeset IDs are in "$HG_PARENT1"
      and "$HG_PARENT2".

    "preupdate"
      Run before updating the working directory. Exit status 0 allows the
      update to proceed. Non-zero status will prevent the update. Changeset ID
      of first new parent is in "$HG_PARENT1". If merge, ID of second new
      parent is in "$HG_PARENT2".

    "listkeys"
      Run after listing pushkeys (like bookmarks) in the repository. The key
      namespace is in "$HG_NAMESPACE". "$HG_VALUES" is a dictionary containing
      the keys and values.

    "pushkey"
      Run after a pushkey (like a bookmark) is added to the repository. The
      key namespace is in "$HG_NAMESPACE", the key is in "$HG_KEY", the old
      value (if any) is in "$HG_OLD", and the new value is in "$HG_NEW".

    "tag"
      Run after a tag is created. ID of tagged changeset is in "$HG_NODE".
      Name of tag is in "$HG_TAG". Tag is local if "$HG_LOCAL=1", in
      repository if "$HG_LOCAL=0".

    "update"
      Run after updating the working directory. Changeset ID of first new
      parent is in "$HG_PARENT1". If merge, ID of second new parent is in
      "$HG_PARENT2". If the update succeeded, "$HG_ERROR=0". If the update
      failed (e.g. because conflicts not resolved), "$HG_ERROR=1".

    Note:
       It is generally better to use standard hooks rather than the generic
       pre- and post- command hooks as they are guaranteed to be called in the
       appropriate contexts for influencing transactions. Also, hooks like
       "commit" will be called in all contexts that generate a commit (e.g.
       tag) and not just the commit command.

    Note:
       Environment variables with empty values may not be passed to hooks on
       platforms such as Windows. As an example, "$HG_PARENT2" will have an
       empty value under Unix-like platforms for non-merge changesets, while
       it will not be available at all under Windows.

    The syntax for Python hooks is as follows:

      hookname = python:modulename.submodule.callable
      hookname = python:/path/to/python/module.py:callable

    Python hooks are run within the Mercurial process. Each hook is called
    with at least three keyword arguments: a ui object (keyword "ui"), a
    repository object (keyword "repo"), and a "hooktype" keyword that tells
    what kind of hook is used. Arguments listed as environment variables above
    are passed as keyword arguments, with no "HG_" prefix, and names in lower
    case.

    If a Python hook returns a "true" value or raises an exception, this is
    treated as a failure.

    "http_proxy"
    """"""""""""

    Used to access web-based Mercurial repositories through a HTTP proxy.

    "host"
        Host name and (optional) port of the proxy server, for example
        "myproxy:8000".

    "no"
        Optional. Comma-separated list of host names that should bypass the
        proxy.

    "passwd"
        Optional. Password to authenticate with at the proxy server.

    "user"
        Optional. User name to authenticate with at the proxy server.

    "always"
        Optional. Always use the proxy, even for localhost and any entries in
        "http_proxy.no". True or False. Default: False.

    "smtp"
    """"""

    Configuration for extensions that need to send email messages.

    "host"
        Host name of mail server, e.g. "mail.example.com".

    "port"
        Optional. Port to connect to on mail server. Default: 25.

    "tls"
        Optional. Method to enable TLS when connecting to mail server:
        starttls, smtps or none. Default: none.

    "username"
        Optional. User name for authenticating with the SMTP server. Default:
        none.

    "password"
        Optional. Password for authenticating with the SMTP server. If not
        specified, interactive sessions will prompt the user for a password;
        non-interactive sessions will fail. Default: none.

    "local_hostname"
        Optional. It's the hostname that the sender can use to identify itself
        to the MTA.

    "patch"
    """""""

    Settings used when applying patches, for instance through the 'import'
    command or with Mercurial Queues extension.

    "eol"
        When set to 'strict' patch content and patched files end of lines are
        preserved. When set to "lf" or "crlf", both files end of lines are
        ignored when patching and the result line endings are normalized to
        either LF (Unix) or CRLF (Windows). When set to "auto", end of lines
        are again ignored while patching but line endings in patched files are
        normalized to their original setting on a per-file basis. If target
        file does not exist or has no end of line, patch line endings are
        preserved. Default: strict.

    "paths"
    """""""

    Assigns symbolic names to repositories. The left side is the symbolic
    name, and the right gives the directory or URL that is the location of the
    repository. Default paths can be declared by setting the following
    entries.

    "default"
        Directory or URL to use when pulling if no source is specified.
        Default is set to repository from which the current repository was
        cloned.

    "default-push"
        Optional. Directory or URL to use when pushing if no destination is
        specified.

    "phases"
    """"""""

    Specifies default handling of phases. See "hg help phases" for more
    information about working with phases.

    "publish"
        Controls draft phase behavior when working as a server. When true,
        pushed changesets are set to public in both client and server and
        pulled or cloned changesets are set to public in the client. Default:
        True

    "new-commit"
        Phase of newly-created commits. Default: draft

    "profiling"
    """""""""""

    Specifies profiling format and file output. In this section description,
    'profiling data' stands for the raw data collected during profiling, while
    'profiling report' stands for a statistical text report generated from the
    profiling data. The profiling is done using lsprof.

    "format"
        Profiling format. Default: text.

        "text"
          Generate a profiling report. When saving to a file, it should be
          noted that only the report is saved, and the profiling data is not
          kept.

        "kcachegrind"
          Format profiling data for kcachegrind use: when saving to a file,
          the generated file can directly be loaded into kcachegrind.

    "output"
        File path where profiling data or report should be saved. If the file
        exists, it is replaced. Default: None, data is printed on stderr

    "revsetalias"
    """""""""""""

    Alias definitions for revsets. See "hg help revsets" for details.

    "server"
    """"""""

    Controls generic server settings.

    "uncompressed"
        Whether to allow clients to clone a repository using the uncompressed
        streaming protocol. This transfers about 40% more data than a regular
        clone, but uses less memory and CPU on both server and client. Over a
        LAN (100 Mbps or better) or a very fast WAN, an uncompressed streaming
        clone is a lot faster (~10x) than a regular clone. Over most WAN
        connections (anything slower than about 6 Mbps), uncompressed
        streaming is slower, because of the extra data transfer overhead. This
        mode will also temporarily hold the write lock while determining what
        data to transfer. Default is True.

    "validate"
        Whether to validate the completeness of pushed changesets by checking
        that all new file revisions specified in manifests are present.
        Default is False.

    "subpaths"
    """"""""""

    Defines subrepositories source locations rewriting rules of the form:

      <pattern> = <replacement>

    Where "pattern" is a regular expression matching the source and
    "replacement" is the replacement string used to rewrite it. Groups can be
    matched in "pattern" and referenced in "replacements". For instance:

      http://server/(.*)-hg/ = http://hg.server/\1/

    rewrites "http://server/foo-hg/" into "http://hg.server/foo/".

    All patterns are applied in definition order.

    "trusted"
    """""""""

    Mercurial will not use the settings in the ".hg/hgrc" file from a
    repository if it doesn't belong to a trusted user or to a trusted group,
    as various hgrc features allow arbitrary commands to be run. This issue is
    often encountered when configuring hooks or extensions for shared
    repositories or servers. However, the web interface will use some safe
    settings from the "[web]" section.

    This section specifies what users and groups are trusted. The current user
    is always trusted. To trust everybody, list a user or a group with name
    "*". These settings must be placed in an *already-trusted file* to take
    effect, such as "$HOME/.hgrc" of the user or service running Mercurial.

    "users"
      Comma-separated list of trusted users.

    "groups"
      Comma-separated list of trusted groups.

    "ui"
    """"

    User interface controls.

    "archivemeta"
        Whether to include the .hg_archival.txt file containing meta data
        (hashes for the repository base and for tip) in archives created by
        the "hg archive" command or downloaded via hgweb. Default is True.

    "askusername"
        Whether to prompt for a username when committing. If True, and neither
        "$HGUSER" nor "$EMAIL" has been specified, then the user will be
        prompted to enter a username. If no username is entered, the default
        "USER@HOST" is used instead. Default is False.

    "commitsubrepos"
        Whether to commit modified subrepositories when committing the parent
        repository. If False and one subrepository has uncommitted changes,
        abort the commit. Default is False.

    "debug"
        Print debugging information. True or False. Default is False.

    "editor"
        The editor to use during a commit. Default is "$EDITOR" or "vi".

    "fallbackencoding"
        Encoding to try if it's not possible to decode the changelog using
        UTF-8. Default is ISO-8859-1.

    "ignore"
        A file to read per-user ignore patterns from. This file should be in
        the same format as a repository-wide .hgignore file. This option
        supports hook syntax, so if you want to specify multiple ignore files,
        you can do so by setting something like "ignore.other = ~/.hgignore2".
        For details of the ignore file format, see the "hgignore(5)" man page.

    "interactive"
        Allow to prompt the user. True or False. Default is True.

    "logtemplate"
        Template string for commands that print changesets.

    "merge"
        The conflict resolution program to use during a manual merge. For more
        information on merge tools see "hg help merge-tools". For configuring
        merge tools see the "[merge-tools]" section.

    "portablefilenames"
        Check for portable filenames. Can be "warn", "ignore" or "abort".
        Default is "warn". If set to "warn" (or "true"), a warning message is
        printed on POSIX platforms, if a file with a non-portable filename is
        added (e.g. a file with a name that can't be created on Windows
        because it contains reserved parts like "AUX", reserved characters
        like ":", or would cause a case collision with an existing file). If
        set to "ignore" (or "false"), no warning is printed. If set to
        "abort", the command is aborted. On Windows, this configuration option
        is ignored and the command aborted.

    "quiet"
        Reduce the amount of output printed. True or False. Default is False.

    "remotecmd"
        remote command to use for clone/push/pull operations. Default is "hg".

    "report_untrusted"
        Warn if a ".hg/hgrc" file is ignored due to not being owned by a
        trusted user or group. True or False. Default is True.

    "slash"
        Display paths using a slash ("/") as the path separator. This only
        makes a difference on systems where the default path separator is not
        the slash character (e.g. Windows uses the backslash character ("\")).
        Default is False.

    "ssh"
        command to use for SSH connections. Default is "ssh".

    "strict"
        Require exact command names, instead of allowing unambiguous
        abbreviations. True or False. Default is False.

    "style"
        Name of style to use for command output.

    "timeout"
        The timeout used when a lock is held (in seconds), a negative value
        means no timeout. Default is 600.

    "traceback"
        Mercurial always prints a traceback when an unknown exception occurs.
        Setting this to True will make Mercurial print a traceback on all
        exceptions, even those recognized by Mercurial (such as IOError or
        MemoryError). Default is False.

    "username"
        The committer of a changeset created when running "commit". Typically
        a person's name and email address, e.g. "Fred Widget
        <fred@example.com>". Default is "$EMAIL" or "username@hostname". If
        the username in hgrc is empty, it has to be specified manually or in a
        different hgrc file (e.g. "$HOME/.hgrc", if the admin set "username ="
        in the system hgrc). Environment variables in the username are
        expanded.

    "verbose"
        Increase the amount of output printed. True or False. Default is
        False.

    "web"
    """""

    Web interface configuration. The settings in this section apply to both
    the builtin webserver (started by "hg serve") and the script you run
    through a webserver ("hgweb.cgi" and the derivatives for FastCGI and
    WSGI).

    The Mercurial webserver does no authentication (it does not prompt for
    usernames and passwords to validate *who* users are), but it does do
    authorization (it grants or denies access for *authenticated users* based
    on settings in this section). You must either configure your webserver to
    do authentication for you, or disable the authorization checks.

    For a quick setup in a trusted environment, e.g., a private LAN, where you
    want it to accept pushes from anybody, you can use the following command
    line:

      $ hg --config web.allow_push=* --config web.push_ssl=False serve

    Note that this will allow anybody to push anything to the server and that
    this should not be used for public servers.

    The full set of options is:

    "accesslog"
        Where to output the access log. Default is stdout.

    "address"
        Interface address to bind to. Default is all.

    "allow_archive"
        List of archive format (bz2, gz, zip) allowed for downloading. Default
        is empty.

    "allowbz2"
        (DEPRECATED) Whether to allow .tar.bz2 downloading of repository
        revisions. Default is False.

    "allowgz"
        (DEPRECATED) Whether to allow .tar.gz downloading of repository
        revisions. Default is False.

    "allowpull"
        Whether to allow pulling from the repository. Default is True.

    "allow_push"
        Whether to allow pushing to the repository. If empty or not set, push
        is not allowed. If the special value "*", any remote user can push,
        including unauthenticated users. Otherwise, the remote user must have
        been authenticated, and the authenticated user name must be present in
        this list. The contents of the allow_push list are examined after the
        deny_push list.

    "guessmime"
        Control MIME types for raw download of file content. Set to True to
        let hgweb guess the content type from the file extension. This will
        serve HTML files as "text/html" and might allow cross-site scripting
        attacks when serving untrusted repositories. Default is False.

    "allow_read"
        If the user has not already been denied repository access due to the
        contents of deny_read, this list determines whether to grant
        repository access to the user. If this list is not empty, and the user
        is unauthenticated or not present in the list, then access is denied
        for the user. If the list is empty or not set, then access is
        permitted to all users by default. Setting allow_read to the special
        value "*" is equivalent to it not being set (i.e. access is permitted
        to all users). The contents of the allow_read list are examined after
        the deny_read list.

    "allowzip"
        (DEPRECATED) Whether to allow .zip downloading of repository
        revisions. Default is False. This feature creates temporary files.

    "baseurl"
        Base URL to use when publishing URLs in other locations, so third-
        party tools like email notification hooks can construct URLs. Example:
        "http://hgserver/repos/".

    "cacerts"
        Path to file containing a list of PEM encoded certificate authority
        certificates. Environment variables and "~user" constructs are
        expanded in the filename. If specified on the client, then it will
        verify the identity of remote HTTPS servers with these certificates.
        The form must be as follows:

      -----BEGIN CERTIFICATE-----
      ... (certificate in base64 PEM encoding) ...
      -----END CERTIFICATE-----
      -----BEGIN CERTIFICATE-----
      ... (certificate in base64 PEM encoding) ...
      -----END CERTIFICATE-----

  This feature is only supported when using Python 2.6 or later. If you wish
  to use it with earlier versions of Python, install the backported
  version of the ssl library that is available from
  ``http://pypi.python.org``.

  You can use OpenSSL's CA certificate file if your platform has one.
  On most Linux systems this will be ``/etc/ssl/certs/ca-certificates.crt``.
  Otherwise you will have to generate this file manually.

  To disable SSL verification temporarily, specify ``--insecure`` from
  command line.

    "cache"
        Whether to support caching in hgweb. Defaults to True.

    "contact"
        Name or email address of the person in charge of the repository.
        Defaults to ui.username or "$EMAIL" or "unknown" if unset or empty.

    "deny_push"
        Whether to deny pushing to the repository. If empty or not set, push
        is not denied. If the special value "*", all remote users are denied
        push. Otherwise, unauthenticated users are all denied, and any
        authenticated user name present in this list is also denied. The
        contents of the deny_push list are examined before the allow_push
        list.

    "deny_read"
        Whether to deny reading/viewing of the repository. If this list is not
        empty, unauthenticated users are all denied, and any authenticated
        user name present in this list is also denied access to the
        repository. If set to the special value "*", all remote users are
        denied access (rarely needed ;). If deny_read is empty or not set, the
        determination of repository access depends on the presence and content
        of the allow_read list (see description). If both deny_read and
        allow_read are empty or not set, then access is permitted to all users
        by default. If the repository is being served via hgwebdir, denied
        users will not be able to see it in the list of repositories. The
        contents of the deny_read list have priority over (are examined
        before) the contents of the allow_read list.

    "descend"
        hgwebdir indexes will not descend into subdirectories. Only
        repositories directly in the current path will be shown (other
        repositories are still available from the index corresponding to their
        containing path).

    "description"
        Textual description of the repository's purpose or contents. Default
        is "unknown".

    "encoding"
        Character encoding name. Default is the current locale charset.
        Example: "UTF-8"

    "errorlog"
        Where to output the error log. Default is stderr.

    "hidden"
        Whether to hide the repository in the hgwebdir index. Default is
        False.

    "ipv6"
        Whether to use IPv6. Default is False.

    "logoimg"
        File name of the logo image that some templates display on each page.
        The file name is relative to "staticurl". That is, the full path to
        the logo image is "staticurl/logoimg". If unset, "hglogo.png" will be
        used.

    "logourl"
        Base URL to use for logos. If unset, "http://mercurial.selenic.com/"
        will be used.

    "name"
        Repository name to use in the web interface. Default is current
        working directory.

    "maxchanges"
        Maximum number of changes to list on the changelog. Default is 10.

    "maxfiles"
        Maximum number of files to list per changeset. Default is 10.

    "port"
        Port to listen on. Default is 8000.

    "prefix"
        Prefix path to serve from. Default is '' (server root).

    "push_ssl"
        Whether to require that inbound pushes be transported over SSL to
        prevent password sniffing. Default is True.

    "staticurl"
        Base URL to use for static files. If unset, static files (e.g. the
        hgicon.png favicon) will be served by the CGI script itself. Use this
        setting to serve them directly with the HTTP server. Example:
        "http://hgserver/static/".

    "stripes"
        How many lines a "zebra stripe" should span in multiline output.
        Default is 1; set to 0 to disable.

    "style"
        Which template map style to use.

    "templates"
        Where to find the HTML templates. Default is install path.