编辑配置文件w/o临时文件

Question

我试图编写一个简单的脚本，在文件的顶部添加一些配置，我就是这样做的：

 #! /bin/bash

 sudo apt-get install monit
 # BELOW IS THE CODE THAT I'M INTERESTING TO CHANGE 
 echo '
 set eventqueue basedir /etc/monit/eventqueue/ slots 1000
 set mmonit http://monit:monit@xxx.xxx.xxx.xxx:8080/collector
 set httpd port 2812 and use address ec2-xxx.xxx.xx.xx.com 
     allow localhost
     allow 0.0.0.0/0.0.0.0
     allow admin:swordfish
 ' | sudo tee -a /etc/monit/monitrc_tmp
sudo cat /etc/monit/monitrc >> /etc/monit/monitrc_tmp
sudo rm /etc/monit/monitrc
sudo mv /etc/monit/monitrc_tmp /etc/monit/monitrc
# UP TO THIS POINT
sudo sed -i 's/set daemon 120/set daemon 20/' /etc/monit/monitrc
exit 0

如您所见，我正试图在文件的顶部添加一些配置，只想知道是否有任何flag或command可以帮助我在不创建tmp文件的情况下完成此操作。

Answer 1

因为你在Linux上，所以看起来像sed -i的一个例子。另外，由于这是系统管理工作，所以保留备份。

sudo sed -i.bak -e '1i\
set eventqueue basedir /etc/monit/eventqueue/ slots 1000\
set mmonit http://monit:monit@xxx.xxx.xxx.xxx:8080/collector\
set httpd port 2812 and use address ec2-xxx.xxx.xx.xx.com\
    allow localhost\
    allow 0.0.0.0/0.0.0.0\
    allow admin:swordfish
' /etc/monit/monitrc

这意味着‘在第1行之前插入以下行’.这些行一直持续到并包括末尾没有反斜杠的行。

您也可以编辑set daemon行，即使您说它超出了范围：

sudo sed -i.bak -e '1i\
set eventqueue basedir /etc/monit/eventqueue/ slots 1000\
set mmonit http://monit:monit@xxx.xxx.xxx.xxx:8080/collector\
set httpd port 2812 and use address ec2-xxx.xxx.xx.xx.com\
    allow localhost\
    allow 0.0.0.0/0.0.0.0\
    allow admin:swordfish
s/set daemon 120/set daemon 20/
' /etc/monit/monitrc

Answer 2

这应该会将行添加到文件的顶部。

  echo -e " set eventqueue basedir /etc/monit/eventqueue/ slots 1000 \n
  set mmonit http://monit:monit@xxx.xxx.xxx.xxx:8080/collector \n
  set httpd port 2812 and use address ec2-xxx.xxx.xx.xx.com \n
      allow localhost \n
      allow 0.0.0.0/0.0.0.0 \n
      allow admin:swordfish \n 
  $(cat /etc/monit/monitrc)" > /etc/monit/monitrc

 sudo sed -i 's/set daemon 120/set daemon 20/' /etc/monit/monitrc
 exit 0