# HG changeset patch # User Arne Babenhauserheide # Date 1240399565 -7200 # Node ID 7a057bf137c5216033c820324b0057619200fca8 # Parent 03591004ed444289b7c2ba77f4b015b82cbe6b04 Added a bastic draft for a quick_start - copied from the mailing list :) . diff -r 03591004ed44 -r 7a057bf137c5 text/quick_start.txt --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/text/quick_start.txt Wed Apr 22 13:26:05 2009 +0200 @@ -0,0 +1,137 @@ += Quick Start = + +When you've been using Mercurial for some time, many things become +second nature, so it's sometimes hard to remember that its basic concepts are +quite revolutionary compared to Subversion. + +Please don't let that intimidate you. Mercurial is damn powerful, even if you +just use the basics (init, commit, log, pull, push, serve, merge). And the +basics are very easy to use, once you see the model behind that: Each +repository has the whole history, and history is not necessarily linear. + +Just stick to these and learn the rest of its commands as you need them. + +As a short intro: + +- init: create a new repository +- commit: save your changes in the current repository +- log: see all changes in your repository +- pull: get all changes from another repository int the current one +- push: get all changes from your repository into another one +- serve: create an instant-webserver. People can see the history there and +pull from it +- merge: join different lines of history + +If you want to see a nice graph of the history, just do "hg serve" in your +repository and then direct your browser to + + http://127.0.0.1:8000 + +This also helps getting a feeling for what the commands do. + +(you can do more finegrained stuff with command options. Just call "hg help +" to see them). + + +I hope your experience with Mercurial will be as great as mine! + +- Arne Babenhauserheide + += Basic concepts of Mercurial = + +//If you're interested in the concepts behind Mercurial, please come with us and listen to a great explanation from Martin Geisler: // + +Let me try to make +some of the basic concepts clear: + +* Like in Subversion, history consists of a number of commits. They're + called changesets in Mercurial. + +* Subversion requires a strict linear ordering of the commits and + gives nice linear revision numbers to them. So revision N has only + one child revision, rN+1. + + This is simple, but it requires a central server to make sure that + everybody agrees on the revision numbers. + +* Mercurial generalizes this by letting each changeset have multiple + children. If I work alone and make commits I'll make + + C1 --> C2 --> C3 + + by making three commits. The commit C3 with no children is a "head". + It is also the newest changeset in the repository -- called "tip". + + If I shared C1 with you and you started your work from that, your + commits will build a repository like this: + + C1 --> C2' --> C3' + + Here C3' is a head in your repository and I don't know anything + about C2' and C3' yet. + +* If I pull from you, or you push to me, the two repositories are + compared. By default, all missing changesets are transferred. This + is all there is to push/pull: compare two graphs of changesets and + transfer the missing ones. + + After a pull from you my repository will look like this: + + /-> C2 --> C3 + C1 -< + \-> C2' --> C3' + + Here C1 has two child changesets, and the repository has two heads + since the development has diverged. + + The changeset C3' will be the new tip since it is the newest + changeset in the repository. Note that tip is always a head, but a + head need not be the tip. + +* Having two heads suggest that someone should merge them -- otherwise + the changes from one will never be combined with the changed made in + the other head. + + When merging with 'hg merge' the task is to figure out the canonical + way to combine the changesets. If the changes do not overlap this is + usually trivial, otherwise you have to do a three-way merge. The + merge must be committed and this creates a changeset which explains + to the world how you think the two heads should be combined: + + /-> C2 --> C3 -\ + C1 -< >-> M + \-> C2' --> C3' -/ + + Note that the merge changeset M has two parents. + + If you do not merge C3 and C3' and try to push you get the 'new + remote head' message and push aborts. It aborts since it is a little + "impolite" to leave the job of merging to someone else -- he who + created the two heads by pulling in some code should also normally + do the merging. + + +> Sometimes it's hard to keep the several DVCS workings in my mind + + It helped me a lot to think in terms of the changeset graph. Remember +that: + + * "hg commit" adds a new node. The parent changesets of the new node + is given by "hg parents" + + * "hg push" and "hg pull" transfer nodes in the graph between two + repositories. + + * "hg update" updates the working copy to reflect a given node in + the history graph. This also changes the parent changeset of the + next commit, see "hg parents". + +> Is there not a simple Mercurial cheat sheet somewhere? + +There are some here: + +http://www.selenic.com/mercurial/wiki/index.cgi/QuickReferenceCardsAndCheatSheets + +- Martin Geisler + +PS: These descriptions were written on the [Mercurial mailinglist](http://selenic.com/mailman/listinfo/mercurial). \ No newline at end of file