Ask HN: how did you learn the command line?

Like others here, I learned simply by doing and fumbling my way around until I was comfortable.

That said, I think the most important thing for you to learn is how to get help. Learn how to find man(ual) pages, and how to interpret the very precise language and syntax that programmer-authors like to use. Then try reading the man pages of the systems that you want to learn - like 'man bash'. Also, some tools have nicer pages accessible via the 'info' command, so try 'info emacs'.

That'll generally be the best way to learn how to use any tool. The only trick past that is to learn which tools exist, and google/stackoverflow will usually suggest appropriate tools when you tell it precisely which problem you want to solve.

I think that in order to learn the command line, you have to immediately develop a different goal that requires proficient use of the command line. That way it'll force you to learn by doing.

Command line is not one of those self-contained "deep" knowledge bases where everything links together. It's broad, shallow, unlinked - the concepts and practices do not always imply themselves. For bodies of knowledge that fit that pattern, you have to learn by doing - you can't simply derive the knowledge through study and thought. And the best way to learn by doing is to immediately apply it to something useful.

I learned mostly thru trial and error with Linux as a teenager, but during my CS degree this course filled in some missing gaps:http://www.cl.cam.ac.uk/teaching/2005/UnixTools/

must have been 1999/2000. My boss made me, the ultimate noob, the "administrator" of a Solaris Box.

I didn't know SHIT! absolutely NOTHING. I was just a dumb Windows User. There was just this blinking cursor (that motherfucker) and me. i browsed the web and had to look up stuff like "cd" and "ls". Steep learning curve, i guess, but nothing teaches you better than "trial and error".

Funny sidenote: Not only was i totally overwhelmed with all the commands and quirks of the command line, but the web always mentioned vim as THE editor for Unix. So i also started messing around with the most obscure editor on this planet.

These were rough times for me, but i have learned so much, and i am thankful for that.

Me too, that's all there was. And that may be the answer: only allow yourself the command line for longer and longer periods of time. Force yourself to learn it.

I really like this book, even today: http://shop.oreilly.com/product/9780596003302.do

The key to being proficient at the command line (as distinct from writing shell scripts) is to think of it as composition.

For example, run this:

  $ file $(which $(man -k python | cut --delimiter " " --fields 1))

(The first '$' is your command line prompt, yours may differ; you don't type that. The other '$' characters you do type.)

Now run each command from the inside out, starting with the man command. See what each command does. Build it up bit by bit, that's exactly what I did, like this:

- the man command

- the man command piped into the cut command

- the man command piped into the cut command after reading "man cut" to remember about the --delimiter option

- the output of that pipeline fed to which

- the output of which fed to file

Note that I didn't use any for loops or variables, the shell did the right thing for me.

Read the man pages for each of those commands.

set -o vi or set -o emacs (or their equivalent in .inputrc) helps a lot when you compose things incrementally. esc-k k k (etc) is your friend if you set -o vi.

Read man bash. It will take you a long time. For today, read the section on READLINE. While in man bash, search for the word READLINE at the front of the line, like this:

/^READLINE

Slash = search

^ = anchor the search to the front of the line

READLINE = what you're searching for in the current man page.

For now, all you need in your ~/.inputrc file is:

set editing-mode vi

This will give you vi command line editing in bash, as well as any other program that uses readline, like the python REPL.

For more info on .inputrc,

  $ man readline

which is documentation for the C interface to readline, but is mostly about how readline is used by a user. For example, in man readline

/VI Mode bindings

gives you all your command line editing commands when you use vi mode.

Get a mostly table of contents of man bash, for your searching pleasure:

  $ man -P cat bash |egrep -v "^ " |egrep -o "^[^ ]+"

Sort it:

  $ man -P cat bash |egrep -v "^ " |egrep -o "^[^ ]+" |sort