Command-line tools such as ls can almost have too many options. Fortunately, aggregates can be formed instead of passing flags one by one. For example, a long command such as ls -l -r -t can be simplified to ls -lrt. And as repeated letters usually lack side effects, amusing words can be obtained such as netstat -satan.

Here are five useful and easy-to-memorize command lines that have been used for the creation of

diff -burN    # compare two files, ignoring whitespaces
du -sm *      # compute folder/file sizes, in megabytes
ls -lart      # display a detailed file listing, order by time
gpg -bass     # sign a file with gpg
netstat -evil # similar to ifconfig -a