Unix Shell脚本-Sed命令

Question

I'm new to unix shell scripting and I wanted to learn how exactly the below command works:

sed "s/~[0-9]*$//" sample_file

I know that sed does an input transformation on a file which is the sample_file that I mentioned above. I wanted to know what exactly s/~[0-9]*$// does.

Help is appreciated.

Answer 1

this regexp removes tilde ~ and numbers that follow the tilde from the given string, if nothing else follows the numbers.

given command will only remove characters in its output. if you need to change file contents, you'll have to add -i like:

sed "s/~[0-9]*$//" -i sample_file