Bash - find a keyword in a file and delete its line [duplicate]

Question

I'd like to give a keyword, find the line where this keyword aṕpears in a file and erase the entire line.

This is what I got but it is not working as it should:

KEYWORD='domain.com'
cat /etc/hosts | grep -v "$KEYWORD" > /etc/hosts

UPDATE

This is what worked for me:

sed -i_bak -e '/domain\.com/d' /etc/hosts

However, as I had two lines with "domain.com", is there a way to tell sed to erase only the line where the exact keyword "domain.com" appears

This is the original content of /etc/hosts:

127.0.0.1       localhost       localhost.localdomain
222.111.22.222      hvn.domain.com
222.111.22.222      domain.com

Here's how it end up after the command sed -i_bak -e '/domain\.com/d' /etc/hosts:

127.0.0.1       localhost       localhost.localdomain

I tried sed -i_bak -e '/\<namourphoto\.com\.br\>/d' ~/Desktop/hosts but it didn't work.

CONCLUSION

This is the code I came up with (based on the help the fine folks have given me):

D=domain.com
DOMAIN=`echo "$D" | sed 's/\./\\\\./g'`
sed -i_bak -e "/[\t]$DOMAIN/d" /etc/hosts

Note that:

• I am counting that there is always a tab before the domain to be erased

• I am automatically escaping the dots of the domain name.

Answer 1

Use the stream editor, sed:

sed -i ".bak" '/culpa/d' test.txt

The above will delete lines containing culpa in test.txt. It will create a backup of the original (named test.txt.bak) and will modify the original file in-place.