diff

Compare files and directories. More information: https://man7.org/linux/man-pages/man1/diff.1.html.

diff old_file new_file

diff -w|--ignore-all-space old_file new_file

diff -y|--side-by-side old_file new_file

diff -u|--unified old_file new_file

diff -r|--recursive old_directory new_directory

diff -r|--recursive -q|--brief old_directory new_directory

diff -a|--text -u|--unified -N|--new-file old_file new_file > diff.patch

diff -d|--minimal --color=always old_file new_file