When you'are working with Subversion, the situation might be familiar: You have checked-out some directories and want to check them in at another repository. Subversion is not happy to do that, it complains with a friendly reminder, that 'your directory' is already under version control.

The proper way to do it, would probably be to export a clean directory tree, but sometimes this option is not available.

Here's a simple shell script to recursively remove all the hidden '.svn' directories:

rm -rf `find . -type d -name .svn`

Wether it is better to use backticks or xargs is being discussed elsewhere.

ln -s /path/to/existing/directory /path/to/new/symbolic/link

After that, a

cd /path/to/new/symbolic/link

brings you to

/path/to/existing/directory

Sometimes a little magic is necessary.

Symbolic link can be removed with a simple 'rm'. This only removes the symbolic link, and not the linked files.

rm /path/to/new/symbolic/link

array_filter($my_array)

array_filter WITHOUT a callback function removes 'false', 'null' and '' fields from an array.

Add the the *_Prefix.pch file of your projects. Strips out NSLogs, when optimized (=Release Build)

Very nice solution, thanks to Marek Bell

// strip out NSLog on optimize
#ifndef __OPTIMIZE__
#    define NSLog(...) NSLog(__VA_ARGS__)
#else
#    define NSLog(...) {}
#endif