Use sed to remove line containing a string

The sed command can be used to remove lines containing a keyword.

Remove line containing string from standard input:

$ echo -e "1\n2\n3"

1
2
3

$ echo -e "1\n2\n3" | sed "/2/d"

1
3

Remove line containing string from a file:

$ echo -e "1\n2\n3" > myfile.txt

$ cat myfile.txt

1
2
3

$ sed -i "" "/2/d" myfile.txt

$ cat myfile.txt

1
3