How to remove everything up to a character within a string?

Question

linux

Hello!
There is a file file.txt with the content:

1_0_0.jpg 2_0_1.jpg 3_0_8.jpg
6_0_4.jpg 7_0_5.jpg 8_0_9.jpg

how to make sure that everything from the symbol _ to .jpg inclusive is deleted from the line so that
1 2 3
6 7 8 remains

Answer 1

str="1_0_0.jpg 2_0_1.jpg 3_0_8.jpg
6_0_4.jpg 7_0_5.jpg 8_0_9.jpg"

echo "$str" | sed -r 's/([0-9]+)[^\.]+\.jpg/\1/g'

Answer 2

Look at the result on the screen
sed -r 's/([0-9]+)\S+/\1/g' file.txt
And fix the file right away
sed -ir 's/([0-9]+)\S+/\1/g' file.txt