Merge pull request LinkedDestiny#4 from reallovelei/master

增加一个 yum 安装项

01-环境搭建及扩展安装.md

@@ -22,7 +22,7 @@ sudo apt-get install build-essential gcc g++ autoconf libiconv-hook-dev libmcryp
 ```
 CentOS环境下：
 ```bash
-yum -y install gcc gcc-c++ autoconf libjpeg libjpeg-devel libpng libpng-devel freetype freetype-devel libxml2 libxml2-devel zlib zlib-devel glibc glibc-devel glib2 glib2-devel bzip2 bzip2-devel ncurses ncurses-devel curl curl-devel e2fsprogs e2fsprogs-devel krb5 krb5-devel libidn libidn-devel openssl openssl-devel openldap openldap-devel nss_ldap openldap-clients openldap-servers gd gd2 gd-devel gd2-devel perl-CPAN
+yum -y install gcc gcc-c++ autoconf libjpeg libjpeg-devel libpng libpng-devel freetype freetype-devel libxml2 libxml2-devel zlib zlib-devel glibc glibc-devel glib2 glib2-devel bzip2 bzip2-devel ncurses ncurses-devel curl curl-devel e2fsprogs e2fsprogs-devel krb5 krb5-devel libidn libidn-devel openssl openssl-devel openldap openldap-devel nss_ldap openldap-clients openldap-servers gd gd2 gd-devel gd2-devel perl-CPAN pcre-devel
 ```
 （注：以上命令是我在实际使用中验证过的可以使用的，可能会和其他教程提供的命令不同）
 当上述命令执行后，即可开始安装PHP。命令如下：