P-2.1 The Command Line

Work through these

• Moving around: directories, listing, and where you actually are

  Almost every early mistake at a terminal comes from being in a different directory than you thought. Getting fluent at printing the current location and listing what is in it removes most of them.

  The Linux command line for beginners · Tutorial

• Looking at files without opening an editor

  Reading the first lines of a large file, the last lines of a log, or searching inside one is faster from the shell than from any editor. These are the commands you will use every day for the rest of your working life.

• Redirection and pipes: sending output somewhere other than the screen

  Output can go into a file, and one program's output can become another's input. This is the whole idea behind small tools that do one thing, and it is why the shell composes so well.

• Searching: finding files by name and finding text inside them

  Two different problems with two different tools, and confusing them wastes a lot of time. Being able to answer where is this defined without an editor open is worth practising deliberately.

• Reading the built-in manual, and permissions when something refuses to run

  The documentation for an installed command is already on the machine, and it is more accurate than most of what a search returns. Permission errors are the other common wall, and they are usually one flag away from being understood.