Bash-script delete a specific line from a .txt file [duplicate]

Question

I want to learn how to delete from a txt file the line that contains a word that user typed in a variable I've tried grep -v but then clears the whole content of the file Help?!!!

Answer 1

Here is an example program how to archive this:

Save this in example.sh:

#!/bin/bash
word="$1" 
grep -F -v "$word"

Save this in test.txt:

Hello world
foo bar
baz bau

Call the program and feed it with the file test.txt on standard input:

chmod u+x example.sh  # Need to do this only once per script (*.sh file)
./example.sh Hello < test.txt

Output ("Hello world" line is deleted):

foo bar
baz bau