How do you delete all lines that begin with “string” in unix sh?

Question

How do you delete all lines in a file that begin with "string" in sh? I was thinking about using the sed command.

Answer 1

grep -v '^string' yourfile.txt > stripped.txt

Answer 2

To do it in place, if your sed supports the -i option, you can do:

sed -i '/^string/d' input-file

Answer 3

sed and grep in your answers are missing their friend awk:

awk '!/^string/' inputfile > resultfile

Answer 4

You can use Vim in Ex mode:

ex -sc g/^string/d -cx file

1. g select all matching lines

2. d delete

3. x save and close