hg is the chemical symbol of the element mercury.
Starting a new repository:
cd myproj
hg init
hg add
hg status
hg commit -m 'Initial import.'
Reviewing changes after editing some files:
hg status
hg diff
hg commit -m 'Refactored widgets.'
hg tip -vp
Clone to a remote repository (note that Mercurial assumes path relative to home directory, so ~ in unnecessary; use // if you need an absolute path):
hg clone ./ ssh://example.com/projects/myproj
Update local repository from remote repository (and update working copy):
hg pull ssh://example.com/projects/myproj/
hg update
Push local changes to a remote repository:
hg status
hg commit -m 'Code cleanup.'
hg push ssh://example.com/projects/myproj/
See a history of changes with hg log -r : or hg log -v. Examine history of a particular changeset with hg log -v -r 3 (where "3" is the start of a changeset id like "3:0272e0d5a517").
Change the working copy to a different revision like hg update 3, and change back to the latest revision with hg update tip.
To stop tracking a file under version control: hg remove myfile.
Also: hg copy file1 file2 and hg rename old new.
See finding and fixing mistakes for how to rollback the last commit (hg rollback), revert pre-commit changes (hg revert file), and more.
If it doesn't already exist, create an .hgignore file in the root of the repository. if you run hg status and see:
M myrepo/foo/doc.tex ? myrepo/foo/doc.aux ? myrepo/foo/doc.log
Add the line myrepo/foo/doc.log to .hgignore, and Mercurial will ignore that file. It should no longer show when you run hg status. You can also add patterns to the ignore file, such as .*.swp to ignore vim's swap files.
After installing Mercurial, create an ~/.hgrc:
[ui]
username = John Smith <jsmith@example.com>
editor = gvim
merge = meld
[merge-tools]
meld.args = $local $other $base
meld.priority = 1
[extensions]
hgext.extdiff =
hgext.hgk =
[extdiff]
cmd.meld =
cmd.vimdiff = gvim
Stick this in myproject/.hg/hgrc:
[paths]
default = ssh://example.com/repo/myproject
Unlike SVN or CVS, Mercurial is a distributed system. Instead of having one central repository from which developers checkout individuals files, in a distributed system each developer clones the entire repository. This is practical because distributed systems are better at merging than SVN or CVS, and faster generally.
A Mercurial repository has a store (stored in the .hg directory) and a working copy. It is possible (and often useful) to checkout older version from the repository into the working copy.
Each commit generates a changeset, which records the state of the working directory. Each changeset has its own changeset ID.
A head is a changeset with not child changesets. A tip is the most recently changed head in a repository.
A branch is a repository, a repository is a branch. Each time you clone a repository, you create a new branch. (Technically, a branch is the set of all changesets with the same branch name. The default branch name is 'default', so a repository will be all once branch unless you create a named branch.)
A tag is a symbolic identifier for a changeset. A local tag (hg tag -l my_tag) is a convenience identifier that is not revision controlled, and doesn't propagate with other changes. A tag with no special specifier (hg tag my_tag) is revision controlled, and does propagate with other changes.