Delete Lines with Awk, Grep, and Sed
Grep
grep -v "yobozoboy" myfile.txt > tmpfile && mv tmpfile myfile.txt
Awk
awk '!/yobozoboy/' myfile.txt > tmpfile && mv tmpfile myfile.txt
Gawk
$ gawk -i inplace '!/yobozoboy/' myfile.txt
Sed
sed -i '/yobozoboy/d' myfile.txt