Tag Archives: CLI

Unit 2 – tutorials and the command line!

Working through the tutorials was fairly easy – I remember many of the concepts from DOS and from working on the old DEC-10 mainframes here at the UA back in the late 70s-early 80s.  The hierarchical file structure of the directories is the same, so navigating was not a problem. Manipulating files was also familiar, since the wildcards work very similarly to what I remember.  I/O redirection also worked much as I had remembered, including the pipes and filters. That part was really fun, trying new combinations in order to get just what I wanted — I had forgotten how powerful they can be!  The file/directory permission commands were new to me; they make sense, but the codes are going to be difficult to remember, especially since I don’t read binary. I seem to recall an alternate method being shown in one of the online video tutorials, but I will have to go back and check. Job control was also fairly straightforward.

The main problem I had was getting stuck without a command prompt. Several times this happened with variations on the cat command; I couldn’t figure out how to quit; I tried ctrl-c and quit and exit, but nothing worked. I had to close the terminal window to kill the process. I read on someone else’s blog that ctrl-z will get the prompt back (and this was also mentioned in the kill section of the tutorial – which I came to AFTER I had the problem). I’m still not sure exactly how the cat command works; I think you need to indicate a file name, or it just ends up echoing back what you type in – which makes sense, since it expects the standard input to be the keyboard and the standard output to the the terminal. I guess I could pipe the output to a file; but then I wouldn’t be able to see what I was typing (I’m guessing). The script command described in one of the other tutorials seems better for this – but anyway I’ll have to experiment.

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Filed under Operating systems, SIRLS 672, Ubuntu Linux