3.9 KiB
#: author: (Moshe Zadka (Community Moderator) https://opensource.com/users/moshez)
Getting started with Mercurial for version control
Learn the basics of Mercurial, a distributed version control system
written in Python.
Mercurial is a distributed version control system written in Python. Because it's written in a high-level language, you can write a Mercurial extension with a few Python functions.
There are several ways to install Mercurial, which are explained in the official documentation. My favorite one is not there: using pip. This is the most amenable way to develop local extensions!
For now, Mercurial only supports Python 2.7, so you will need to create a Python 2.7 virtual environment:
python2 -m virtualenv mercurial-env
./mercurial-env/bin/pip install mercurial
To have a short command, and to satisfy everyone's insatiable need for chemistry-based humor, the command is called hg.
$ source mercurial-env/bin/activate
(mercurial-env)$ mkdir test-dir
(mercurial-env)$ cd test-dir
(mercurial-env)$ hg init
(mercurial-env)$ hg status
(mercurial-env)$
The status is empty since you do not have any files. Add a couple of files:
(mercurial-env)$ echo 1 > one
(mercurial-env)$ echo 2 > two
(mercurial-env)$ hg status
? one
? two
(mercurial-env)$ hg addremove
adding one
adding two
(mercurial-env)$ hg commit -m 'Adding stuff'
(mercurial-env)$ hg log
changeset: 0:1f1befb5d1e9
tag: tip
user: Moshe Zadka <[moshez@zadka.club][4]>
date: Fri Mar 29 12:42:43 2019 -0700
summary: Adding stuff
The addremove command is useful: it adds any new files that are not ignored to the list of managed files and removes any files that have been removed.
As I mentioned, Mercurial extensions are written in Python—they are just regular Python modules.
This is an example of a short Mercurial extension:
from mercurial import registrar
from mercurial.i18n import _
cmdtable = {}
command = registrar.command(cmdtable)
@command('say-hello',
[('w', 'whom', '', _('Whom to greet'))])
def say_hello(ui, repo, **opts):
ui.write("hello ", opts['whom'], "\n")
A simple way to test it is to put it in a file in the virtual environment manually:
`$ vi ../mercurial-env/lib/python2.7/site-packages/hello_ext.py`
Then you need to enable the extension. You can start by enabling it only in the current repository:
$ cat >> .hg/hgrc
[extensions]
hello_ext =
Now, a greeting is possible:
(mercurial-env)$ hg say-hello --whom world
hello world
Most extensions will do more useful stuff—possibly even things to do with Mercurial. The repo object is a mercurial.hg.repository object.
Refer to the official documentation for more about Mercurial's API. And visit the official repo for more examples and inspiration.
via: https://opensource.com/article/19/4/getting-started-mercurial
作者：Moshe Zadka (Community Moderator) 选题：lujun9972 译者：译者ID 校对：校对者ID