view mercurial/help/hgignore.txt @ 34857:84c6b9384d6a

log: add -L/--line-range option to follow file history by line range

We add an experimental -L/--line-range option to 'hg log' taking file patterns
along with a line range using the (new) FILE,FROMLINE-TOLINE syntax where FILE
may be a pattern (matching exactly one file). The resulting history is similar
to what the "followlines" revset except that, if --patch is specified,
only diff hunks within specified line range are shown.

Basically, this brings the CLI on par with what currently only exists in hgweb
through line selection in "file" and "annotate" views resulting in a file log
with filtered patch to only display followed line range.

The option may be specified multiple times and can be combined with --rev and
regular file patterns to further restrict revisions. Usage of this option
requires --follow; revisions are shown in descending order and renames are
followed. Only the --graph option is currently not supported.

The UI is the result of a consensus from review feedback at:

  https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-October/106749.html


The implementation spreads between commands.log() and cmdutil module.
In commands.log(), the main loop may now use a "hunksfilter" factory (similar
to "filematcher") that, for a given "rev", produces a filtering function
for diff hunks for a given file context object.
The logic to build revisions from -L/--line-range options lives in
cmdutil.getloglinerangerevs() which produces "revs", "filematcher" and
"hunksfilter" information. Revisions obtained by following files' line range
are filtered if they do not match the revset specified by --rev option. If
regular FILE arguments are passed along with -L options, both filematchers are
combined into a new matcher.

.. feature::

   Add an experimental -L/--line-range FILE,FROMLINE-TOLINE option to 'hg log'
   command to follow the history of files by line range. In combination with
   -p/--patch option, only diff hunks within specified line range will be
   displayed. Feedback, especially on UX aspects, is welcome.

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/