[SOLVED] Delete everything after pattern including pattern

Issue

I have a text file like

some
important
content
goes here
---from here--
some 
unwanted content

I am trying to delete all lines after ---from here-- including ---from here--. That is, the desired output is

some
important
content
goes here

I tried sed '1,/---from here--/!d' input.txt but it's not removing the ---from here-- part. If I use sed '/---from here--.*/d' input.txt, it's only removing ---from here-- text.

How can I remove lines after a pattern including that pattern?

EDIT

I can achieve it by doing the first operation and pipe its output to second, like sed '1,/---from here--/!d' input.txt | sed '/---from here--.*/d' > outputput.txt.
Is there a single step solution?

Solution

Another approach with sed:

sed '/---from here--/,$d' file

The d(delete) command is applied to all lines from first line containing ---from here-- up to the end of file($)

Answered By - SLePort