[问题求助] sed如何替换指定文本中的特定字符串

etplus

想要批量修改Linux 的一些配置文件
对sed不是太熟悉，找到了这个比较笨的方法，修改HOSTNAME成功了
可是修改SELINUX的配置文件确出了问题

#sed -i '/HOSTNAME/d' /etc/sysconfig/network 
#echo  'HOSTNAME=testname' >> /etc/sysconfig/network
 
#sed -i '/SELINUX/d' "/etc/selinux/config"
#echo  'SELINUX=disablexxx' >> "/etc/selinux/config"COPY

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted COPY

# This file controls the state of SELinux on the system.
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
 
 
SELINUX=disablexxxCOPY

修改完了，成了这样，后面的内容都被删除了。
正确的使用sed修改某个参数的方法是什么？

etplus

回复 3# DiamondbacK

好用多谢，试着理解理解我