Introduction to Mercurial (Hg) I presented this session in the Java Developers Conference in Egypt, 2012.

1. Hosam Aly, JDC 2012

2. Introduction to Mercurial (Hg)
 Distributed Version
Control System
 Practical demo
 Under the hood
(if time permits)
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3. Centralized Version Control
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4. Centralized Version Control
 When you check new code in,
everybody else gets it.
 You can check in buggy code and drive
everyone else crazy, or...
 You can avoid checking it in until it’s fully
debugged, even if it takes weeks.
 You lose the benefit
of version control!
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5. Centralized Version Control
 Different Versions / New Features:
Branch and Merge
 But SVN has a bad merging reputation!
 From the SVN Book v1.6 (§4.4.11):
The bottom line is that Subversion's merge-
tracking feature has an extremely complex
internal implementation. Because the
feature is relatively new, a numbers of edge
cases and possible unexpected behaviors
may pop up.
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6. Distributed Version Control
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7. Practical Demo
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8. Mercurial Commands
 Init
 Clone
 Commit
 Push
 Pull
 Update
 Revert
 Rollback
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9. Mercurial Advantages
 Locally accessible repository
 History information available all the time
 Fast operations using local data
 Backup on every machine!
 Easy branching and merging
 Branches can be named or unnamed
 Using changesets makes merging painless
 Encourages quick, throw-away prototyping
 Guarantees data integrity
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10. Mercurial Advantages (2)
 Very easy sharing, even without a
server!
 Safety of user’s changes when updating
 Sane history management
 Ability to recover from unpublished mistakes
 Ability to revert (backout) an old changeset
 Cross-platform first-class tool support
 With plugins for many IDEs
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11. Mercurial Advantages (3)
 Efficient management of tiered repositories
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12. Similar Tools
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Bazaar

13. Usability vs. Power
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Martin Fowler
Version Control Tools
17 Feb 2010

14. Mercurial Adoption
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15. Questions and Answers
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16. Resources
 Official Mercurial Wiki
http://mercurial.selenic.com/wiki/
 HgInit, Joel Spolsky’s tutorial
http://hginit.com
 Martin Geisler’s Presentations
http://cdn.bitbucket.org/mg/mercurial-talk/downloads/ibm-
2010-09-16.pdf
 Mercurial: The Definitive Guide book
http://hgbook.red-bean.com/
 More Presentations and Publications
http://mercurial.selenic.com/wiki/Presentations
 Source Control Made Easy, an excellent podcast about
DVCS Internals by Jim Weirich
http://pragprog.com/screencasts/v-jwsceasy/source-
control-made-easy
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17. Acknowledgement
 Most of the materials presented in this
presentation were aided by existing
content from Joel Spolsky, Martin
Geisler and Jim Weirich. I owe much of
my knowledge about Mercurial and
DVCS to them. If it weren’t for their
publicly available content, this
presentation would have been much
less useful. Many thanks.
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18. hosamaly@acm.org
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