How to ignore build directory in SVN from command line

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This works for Windows/Mac/Linux, but its tested on Mac. On Windows, you can do it easily with Free TortoiseSVN Shell context menu, so this method will be useful on Mac/Linux.

Lets suppose your folder structure is
SVNfolder->trunk->development->Projectfolder->build

Now open terminal and cd to development. (Now if you 'ls' it wil' list Projectfolder)
type svn propset svn:ignore "build" Projectfolder/  and press Enter.

and that is it, your build folder will be ignored.