需要先安装xcode命令行工具
在终端中运行下面命令
curl -O http://ftp.gnu.org/gnu/wget/wget-1.14.tar.gz
tar -xzvf wget-1.14.tar.gz
cd wget-1.14
./configure --with-ssl=openssl
make
sudo make install
which wget
关于with-ssl=openssl，如果不带这个参数将会出现下面错误
...
checking for compress in -lz... yes
checking for gpg_err_init in -lgpg-error... no
checking for gcry_control in -lgcrypt... no
checking for libgnutls... no
configure: error: --with-ssl was given, but GNUTLS is not available.
这是因为wget默认使用GNUTLS作为ssl的库，而Mac OS X不包含GNUTLS