sed相关

刚才看酒哥的博客，一篇关于系统优化的shell脚本。

其中有一段：

ssh_cf="/etc/ssh/sshd_config"   

sed -i -e '74 s/^/#/' -i -e '76 s/^/#/' $ssh_cf

 

 

其含义，定义ssh_cf为/etc/ssh/sshd_config，

把74行和76行注释掉。 

sed -i就直接改变原文，如果同时更改多个的话，要加e选项，s是替换，^表示开头，

把开头替换成#，就是注释。

 

今天遇到的问题是这样的：

需要把下边文件中的 ：

ACTIVE_CONSOLES =/dev/tty[1- 6 ] 改为 ACTIVE_CONSOLES =/dev/tty[1-3 ]

[root@CentOS ~]# vim /etc/sysconfig/init

# color => new RH6.0 bootup
# verbose => old-style bootup
# anything else => new style bootup without ANSI colors or positioning
BOOTUP=color
# column to start "[  OK  ]" label in
RES_COL=60
# terminal sequence to move to that column. You could change this
# to something like "tput hpa ${RES_COL}" if your terminal supports it
MOVE_TO_COL="echo -en \\033[${RES_COL}G"
# terminal sequence to set color to a 'success' color (currently: green)
SETCOLOR_SUCCESS="echo -en \\033[0;32m"
# terminal sequence to set color to a 'failure' color (currently: red)
SETCOLOR_FAILURE="echo -en \\033[0;31m"
# terminal sequence to set color to a 'warning' color (currently: yellow)
SETCOLOR_WARNING="echo -en \\033[0;33m"
# terminal sequence to reset to the default color.
SETCOLOR_NORMAL="echo -en \\033[0;39m"
# Set to anything other than 'no' to allow hotkey interactive startup...
PROMPT=yes
# Set to 'yes' to allow probing for devices with swap signatures
AUTOSWAP=no
# What ttys should gettys be started on?
ACTIVE_CONSOLES=/dev/tty[1-6]
# Set to '/sbin/sulogin' to prompt for password on single-user mode
# Set to '/sbin/sushell' otherwise
SINGLE=/sbin/sushell

 

自己才疏学浅试了好多不行，然后发到几个不同的群里，看下大牛们给的回复：

[root@CentOS ~]# sed -i 's/ACTIVE_CONSOLES=\/dev\/tty\[1-6\]/ACTIVE_CONSOLES=\/dev\/tty\[1-3\]/' /etc/sysconfig/init

[root@CentOS ~]# sed -i '/ACTIVE_CONSOLE/s/\[1-6\]/[1-3]/' /etc/sysconfig/init

[root@CentOS ~]# sed -i '/ACTIVE_CONSOLES/s#6#3#'