Search for a keyword in every file that has been changed in the last 20 commits of a specific author

gistfile1.txt

# Replace AUTHOR_NAME with the author's name
# Replace KEYWORD with the keyword you wanna find

for x in $(git log --author=AUTHOR_NAME --pretty=format:'%h' -n 20 | cut -d" " -f1) ; do for y in $(git show --pretty="format:" --name-only $x) ; do if [ -f $y ]; then echo $y ; grep -in 'KEYWORD' $y ; fi ; done ;  done