从Bash中的字符串中提取字符串

Question

The script reads in lines from a text file. A line looks like this.

227 A S  comment=comment string dst-address=9.9.9.9/29 gateway=192.168.199.2 gateway-status=192.168.199.2 reachable via  LACP1=1 scope=30 target-scope=10

This is assigned the variable $route

I then need to then assign 9.9.9.9/29 as the variable $subnet . I can't use awk because the column position of dst-address will vary in the lines.

To recap I need to search each line for " dst-address= " and then assign the string after the '=' to the variable $subnet.

My ideal solution is

while read routes ; do
    subnet=< code I need >
done < /tmp/routingTable.txt

Answer 1

Perl解决方案：

perl -n -e'/dst-address=(\S+)/ && print $1."\n"' your_file

Answer 2

一个无循环的bash解决方案

echo $route | sed -r "s/.*dst-address=([0-9./]+).*/\1/"