64位redhat编译执行32位c++程序（redhat安装centos源）

cat /etc/issue 查看系统版本

我测试的是redhat6.7版本

编译32位程序需要一个32位c++库：libstdc++

首先将redhat更换成centos的安装源，便于使用yum在线安装程序

1、删除redhat原有的yum源

# rpm -aq | grep yum|xargs rpm -e --nodeps

2、下载新的yum安装包 

　　这里我们使用CentOS的yum源

# wget http://mirror.centos.org/centos/6.0/os/i386/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
# wget http://mirror.centos.org/centos/6.0/os/i386/Packages/yum-metadata-parser-1.1.2-14.1.el6.i686.rpm
# wget http://mirror.centos.org/centos/6.0/os/i386/Packages/yum-3.2.27-14.el6.centos.noarch.rpm
# wget http://mirror.centos.org/centos/6.0/os/i386/Packages/yum-plugin-fastestmirror-1.1.26-1.el6.noarch.rpm

如果wget不了，可以试着到http://mirrors.163.com/centos/6/os/x86_64/Packages/找

3、安装yum软件包

# rpm -ivh  python-iniparse-0.3.1-2.1.el6.noarch.rpm
# rpm -ivh  yum-metadata-parser-1.1.2-14.1.el6.i686.rpm
# rpm -ivh  yum-3.2.27-14.el6.centos.noarch.rpm  yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm

　　注意：最后两个安装包要放在一起同时安装，否则会提示相互依赖，安装失败。

4、更改yum源  #我们使用网易的CentOS镜像源

# cd /etc/yum.repos.d/
# wget  http://mirrors.163.com/.help/CentOS6-Base-163.repo
# vi CentOS6-Base-163.repo

　　编辑文件，把文件里面的$releasever全部替换为版本号，即6 最后保存！或者直接把下面的内存拷贝到CentOS6-Base-163.repo文件中即可（已经修改好）

#########################################################################
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#

[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#released updates
[updates]
name=CentOS-6 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

#########################################################################

5、清理yum缓存

# yum clean all
# yum makecache     #将服务器上的软件包信息缓存到本地,以提高搜索安装软件的速度
# yum install vim*    #测试域名是否可用

　　至此，Redhat6可以使用CentOS的yum源在线安装软件了！

在编译时使用-m32编译，在链接时使用-m elf_i386

CFLAGS = -g -O -DDBG -D_REENTRANT -Wall -DUSE_PTHREAD -pthread -m32
LDFLAGS = -ldl -lnsl -lm -lpthread -lstdc++ -m elf_i386

编译时发现缺少lstdc++,其实是系统没有安装libstdc++的32位库

yum provides libstdc++.so.6

可以看到提示安装libstdc++-4.4.7-16.el6.i686

yum install libstdc++-4.4.7-16.el6.i686 即可

最重要的一点：如果是编译的server的程序，记得关掉防火墙

chkconfig iptables off

可能还要yum install glibc-devel.i686