linux中在指定字符前后新增内容，sed命令

cat /home/qypt/lac/aaa.txt  先查看服务器上面某个配置文件的参数，

1.现在要在S0000025后面加个,S0000023命令：sed -i 's/S0000025/&S0000023/' /home/qypt/lac/aaa.txt

2.如果要在S0000025之前加S0000024,命令：sed -i 's/S0000025/S0000024&/' /home/qypt/lac/aaa.txt