CentOS中yum里没有Git，需要手动安装。

首先需要安装git的依赖包

yum install curl
yum install curl-devel
yum install zlib-devel
yum install openssl-devel
yum install perl
yum install cpio
yum install expat-devel
yum install gettext-devel

下载最新的git包

wget http://www.codemonkey.org.uk/projects/git-snapshots/git/git-latest.tar.gz
tar xzvf git-latest.tar.gz
cd git-xxxx-xx-xx
autoconf
./configure
make | make install

验证是否安装成功：检查安装的版本

git --version

------------------------ 12-18日更新 --------------------

经朋友提示，在检查完以上依赖包后，还有可能出现一种错误，如下所示：

/usr/bin/perl Makefile.PL PREFIX='/usr/local' INSTALL_BASE='' --localedir='/usr/local/share/locale'
 Can't locate ExtUtils/MakeMaker.pm in @INC (@INC contains: /usr/local/lib/perl5 /usr/local/share/perl5 /usr/lib/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib/perl5 /usr/share/perl5 .) at Makefile.PL line 3.
 BEGIN failed--compilation aborted at Makefile.PL line 3.
 make[1]: *** Error 2
 make: *** Error 2

提示是perl的问题，使用yum search perl-devel查出一些包。

yum install perl-devel.i686

继续make | make install。 成功！