view mercurial/help/hgignore.txt @ 26755:bb0b955d050d

streamclone: support for producing and consuming stream clone bundles

Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.

This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).

The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.

Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.

We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.

It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.

Synopsis
========

The Mercurial system uses a file called ``.hgignore`` in the root
directory of a repository to control its behavior when it searches
for files that it is not currently tracking.

Description
===========

The working directory of a Mercurial repository will often contain
files that should not be tracked by Mercurial. These include backup
files created by editors and build products created by compilers.
These files can be ignored by listing them in a ``.hgignore`` file in
the root of the working directory. The ``.hgignore`` file must be
created manually. It is typically put under version control, so that
the settings will propagate to other repositories with push and pull.

An untracked file is ignored if its path relative to the repository
root directory, or any prefix path of that path, is matched against
any pattern in ``.hgignore``.

For example, say we have an untracked file, ``file.c``, at
``a/b/file.c`` inside our repository. Mercurial will ignore ``file.c``
if any pattern in ``.hgignore`` matches ``a/b/file.c``, ``a/b`` or ``a``.

In addition, a Mercurial configuration file can reference a set of
per-user or global ignore files. See the ``ignore`` configuration
key on the ``[ui]`` section of :hg:`help config` for details of how to
configure these files.

To control Mercurial's handling of files that it manages, many
commands support the ``-I`` and ``-X`` options; see
:hg:`help <command>` and :hg:`help patterns` for details.

Files that are already tracked are not affected by .hgignore, even
if they appear in .hgignore. An untracked file X can be explicitly
added with :hg:`add X`, even if X would be excluded by a pattern
in .hgignore.

Syntax
======

An ignore file is a plain text file consisting of a list of patterns,
with one pattern per line. Empty lines are skipped. The ``#``
character is treated as a comment character, and the ``\`` character
is treated as an escape character.

Mercurial supports several pattern syntaxes. The default syntax used
is Python/Perl-style regular expressions.

To change the syntax used, use a line of the following form::

  syntax: NAME

where ``NAME`` is one of the following:

``regexp``
  Regular expression, Python/Perl syntax.
``glob``
  Shell-style glob.

The chosen syntax stays in effect when parsing all patterns that
follow, until another syntax is selected.

Neither glob nor regexp patterns are rooted. A glob-syntax pattern of
the form ``*.c`` will match a file ending in ``.c`` in any directory,
and a regexp pattern of the form ``\.c$`` will do the same. To root a
regexp pattern, start it with ``^``.

Subdirectories can have their own .hgignore settings by adding
``subinclude:path/to/subdir/.hgignore`` to the root ``.hgignore``. See
:hg:`help patterns` for details on ``subinclude:`` and ``include:``.

.. note::

  Patterns specified in other than ``.hgignore`` are always rooted.
  Please see :hg:`help patterns` for details.

Example
=======

Here is an example ignore file. ::

  # use glob syntax.
  syntax: glob

  *.elc
  *.pyc
  *~

  # switch to regexp syntax.
  syntax: regexp
  ^\.pc/