Just like last week, where we wanted to replace a string, we can use sed for this task:
sed '/pouet/d' file.txtThis will output file.txt on stdout without the lines containing pouet.
On Linux systems, you can add the -i option to delete the lines inplace.
On Mac systems you can use -i .bak to also delete the lines inplace, but you need to tell how to name the backup of the original file (named file.txt.bak in this example).
I like
grep -v word file.txt > file_without_word.txt