How to undo a commit partially in Subversion?

If I do commit a change in Subversion, say to revision 330 ( which consists of 3 different independent codes files, a b and c ) and then realise that I need to revert back the older version of c and undo the commit changes only related to file c. How do I do it without touching the other two files a and b? Basically partially undo commit 330...

I am not using Tortoise SVN and would apprec开发者_StackOverflow中文版iate if someone could tell me to do this through the svn client command line.

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svn merge -r 330:329 c
svn commit -m "Rollback to revision 329"