LinuxCommand

Не могу не поделиться случайной находкой, LinuxCommand.org. Шелл, скрипты, команды. Все для нас.
Вот, что пишет автор про мотивы:

Why do you need to learn the command line anyway? Well, let me tell you a story. Not long ago we had a problem where I used to work. There was a shared drive on one of our file servers that kept getting full. I won't mention that this legacy operating system did not support user quotas; that's another story. But the server kept getting full and stopping people from working. One of the software engineers in our company spent the better part of a day writing a C++ program that would look through the directories of all the users and add up the space they were using and make a listing of the results. Since I was forced to use the legacy OS while I was on the job, I installed a version of the bash shell that works on it. When I heard about the problem, I realized I could do all the work this engineer had done with this single line:

du -s * | sort -nr > $HOME/space_report.txt

linuxcommand.org/learning_the_shell

Типа "наш инженер потратил лучшую часть дня в писании программы на С++ для подсчета места на диске по каждому пользователю... а я написал одну строку...". Это, типа, иллюстрирует полезность командной строки.
Ну, в целом, да. Хотя можно вспомнить примеры и пополезнее.