把Mac OS X 升级到10.8.2。
安装了Xcode4.5之后。
还是老样子，想在bash中用svn命令行，但是失败了
“-bash: svn: command not found”
解决方法：
打开Xcode,左上角苹果符号旁边Xcode选择 Preferences
选择Downloads，把Command Line Tools下载了
Before installing, note that from within Terminal you can use the XCRUN tool to launch compilers and other tools embedded within the Xcode application. Use the XCODE-SELECT tool to define which version of Xcode is active. Type "man xcrun" from within Terminal to find out more.Downloading this package will install copies of the core command line tools and system headers into system folders, including the LLVM compiler, linker, and build tools.
下载好了，bash的svn命令就能用了