Versioning Systems

1
Versioning Systems
Has one of your projects ever looked like this ?
Working alone Probably manageable Working in a
group Good luck!
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Versioning Systems Ways of avoiding a repository
mess

• Versioning Systems allow
• To store one master copy of the source code
• multiple users to modify the same code
• automated updates between versions
• Access to any previous state of the source code

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CVS dos and donts

• Facilitates bug detection when software is
  modified
• Economy in disk space while saving versions
• Prevents code over-writing in a team project

• Not a build system
• Not a substitute for communication between
  developers or for management
• No change control available

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Revision numbers
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DISCOVER example session Variables

• Setting up variables
• CVS_RSH What remote shell to use
• CVSROOT Tells where the repository is
• Example
• sh/ksh export CVS_RSHssh
• csh setenv CVS_RSH ssh
• sh/ksh export CVSROOT/caip/u2/DevGroup/cvsroot/
  
• csh setenv CVSROOT /caip/u2/DevGroup/cvsroot

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DISCOVER example session Getting the source
code

• Get to a working directory on local computer (cd
  /work/)
• cvs checkout DISCOVER/Client/java or
• cvs co DISCOVER/Client/java
• Will download all source files into the current
  directory.
• Similarly using Module name Client
• cvs co Client

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DISCOVER example session Committing a change

• Checking file in repository
• cvs commit ltfile1gt,ltfile2gt,
• If no filename is given all files are scanned by
  CVS and all modified files are committed.

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DISCOVER example session Adding a file

• To add a file or directory to be checked by CVS
• cvs add ltfile1gt,ltfile2gt,
• cvs commit
• To add an entire directory of source files
• cvs import ltrepositorygt ltvtaggt ltrtaggt
• repository is the directory name in the
  repository
• vtag is a vendor tag for entire branch 1.1.1
• rtag is a release tag

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DISCOVER example session removing a file

• Local file needs to be deleted and then removed
  from the repository
• rm ltfile1gt,ltfile2gt,
• cvs remove ltfile1gt,ltfile2gt,
• cvs commit

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Branches

• Tag symbolic name for revision of file
• -v flag in status see tags and rev. nos.
• Tag all files at strategic points release
• -r flag in checkout checkout a rev. no.
• Need for branches good for bug-fixing
• Put modified code in branch and later merge with
  main trunk

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DISCOVER example session branching out

• Create your independent branch (harmless to the
  main trunck)
• cvs b r release1-0 release1-0-patch SRC
• Merging a branch back to the main trunck
• cvs j ltbranchnamegt

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Modules

• modules are alias names to projects kept in the
  repository.
• More convenient to call a module name rather
  than a long pathname
• Example
• If repository is in
• /home/cvsroot/Project_AX/Client/Synchronous/withLi
  mit
• A module could declare this simply as Client

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Defining the module

• Get working copy of modules file
• Edit file to define new module
• Commit changes to modules file
• Release the working copy
• Eg - cvs checkout CVSROOT/modules
• new line newdir newcode/newdir
• cvs commit m Added module modules
• cvs release d modules

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cvs Status

• Status gives the state of the file
• Up-to-date latest revision
• Locally modified not committed changes
• Locally added added but not committed
• Locally removed removed, not committed
• Needs checkout, Needs merge
• Unresolved Conflict update conflict
• Unknown

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Tracking mechanisms

• cvs watchinfo to inform other about commits
• cvs watch on/off places watch on files
  working copies created as read-only
• cvs watch add/remove CVS notification
• cvs edit/unedit edit/abandon watched files
• cvs watchers/editors list of users watching
  changes or working on files

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Links
GNUs site on CVS http//www.gnu.org/manual/cvs/h
tml_chapter/cvs_20.html CVS Man
page http//hoth.stsci.edu/man/man1/cvs.html