Delete lines from text file after copying to a another file

Python, Perl and Golang Python
1

Hi,

vi test.txt

sun
sun
moon
star
moon

Now when I execute the command,

cat test.txt | grep sun > sun.txt

text “sun” is copied to a file.

I need a help how to delete the lines which has “sun” from text.txt and save the file

2

Use grep’s inverse option and redirect back into the file:

cat test.txt | grep -v sun > test.txt

Cheers,
D.

3

To sum up:

cat test.txt | grep sun > sun.txt && cat test.txt | grep -v sun > test.txt