How to extract the content between specific strings in a shell?

In the shell, the sed command can be used to extract the content between specified strings. Let’s say we have the following string:

string="Hello, <world>!"

To extract the content between the , you can use the following command:

result=$(echo $string | sed 's/.*<\(.*\)>.*/\1/')
echo $result

The output is:

world

This command utilizes regular expressions to match and extract the content between < and >.