2013 Resolutions: a man page a day makes the newb go away

Post by malandrew » Mon, Dec 31, 2012, 9:38 PM UTC

  (1) What is the command
  (2) What kinds of things you can accomplish with it 
      (i.e. why should I learn this command? how will 
      it benefit me)
  (3) Examples of the command applied by itself
  (4) Examples of the command applied in conjunction with
      commands you've previously written about via piping.

Post by a3_nm » Mon, Dec 31, 2012, 9:49 PM UTC

sobering wrote: post #5

seanwoods wrote: post #4

How will you know which man page to read "next"?

So far the plan is to start with "man" and then go through the man pages of my most commonly used commands: cd, ls, grep, cat, sed, etc. After that, I may write a little shell script that simply opens one at random for me.

Post by malandrew » Tue, Jan 01, 2013, 7:42 PM UTC

sobering wrote: post #44

malandrew wrote: post #41

One thing I'd love to see if you embark and stick to this new year's resolution is creating a blog post per man page with all the exercises and examples you tried out by applying what you've learned from each man page. It'd be great if each post included something like: (1) What is the command (2) What kinds of things you can accomplish with it (i.e. why should I learn this command? how will it benefit me) (3) Exampl…

That's what I had planned. Thanks for creating an outline for me. ;)

Post by npsimons » Wed, Jan 02, 2013, 6:22 PM UTC

ciupicri wrote: post #19

sobering wrote: post #10

Earlier quoted context omitted.

Just found this little snippet via a quick Google search: dir="/bin"; man $(ls $dir |sed -n "$(echo $(( $RANDOM % $(ls $dir |wc -l | awk "{ print $1; }" ) + 1 )) )p") I think I may write my own version as well. Just to gain a bit more experience with shell scripting.

Unfortunately there are a couple of commands that don't have a man page, e.g. mpplu (from argyllcms-1.4.0-2.fc17.x86_64) or showchar (from psutils-1.17-38.fc17.x86_64).

  ;; Taken from http://emacswiki.org/emacs/ElispCookbook#toc57
  (defun directory-dirs (dir)
    "Find all directories in DIR."
    (unless (file-directory-p dir)
      (error "Not a directory `%s'" dir))
    (let ((dir (directory-file-name dir))
          (dirs '())
          (files (directory-files dir nil nil t)))
      (dolist (file files)
        (unless (member file '("." ".."))
          (let ((file (concat dir "/" file)))
            (when (file-directory-p file)
              (setq dirs (append (cons file
                                       (directory-dirs file))
                                 dirs))))))
      dirs))

  ;; Taken from
  ;; http://stackoverflow.com/questions/3815467/stripping-duplicate-elements-in-a-list-of-strings-in-elisp
  (defun strip-duplicates (list)
    (let ((new-list nil))
      (while list
        (when (and (car list) (not (member (car list) new-list)))
          (setq new-list (cons (car list) new-list)))
        (setq list (cdr list)))
      (nreverse new-list)))

  ;; Display a random manual page
  (defun open-random-man-page ()
    (interactive)
    ;; Get manual page paths from the environment.
    (setq man-paths (parse-colon-path (getenv "MANPATH")))
    (setq man-dirs ())
    (dolist (man-path man-paths)
      (setq man-dirs (append man-dirs (directory-dirs man-path))))

    ;; Get a list of files in manual page paths.
    (setq files ())
    (dolist (man-dir man-dirs)
      (setq files (append files (directory-files man-dir nil "^[^\.].*"))))

    ;; Fixup the files to be a list of man pages.
    (setq man-pages ())
    (dolist (file files)
      (setq man-pages (cons (car (split-string file "\\." t)) man-pages)))

    (setq man-pages (strip-duplicates man-pages))

    (random t)
    (man (nth (random (length man-pages)) man-pages)))

Post by npsimons » Fri, Jan 04, 2013, 6:23 PM UTC

npsimons wrote: post #47

ciupicri wrote: post #19

Earlier quoted context omitted.

Unfortunately there are a couple of commands that don't have a man page, e.g. mpplu (from argyllcms-1.4.0-2.fc17.x86_64) or showchar (from psutils-1.17-38.fc17.x86_64).

I know the OP said he was a VIM guy, but here's my first approximation to a random manual page script for emacs; it doesn't strip out directories (like man1) or specify different sections of the manual, but it indexes manual pages, so you not only won't try opening pages for commands that don't have them, but you'll get other pages too (eg, the TCL library man pages): ;; Taken from http://emacswiki.org/emacs/ElispCoo…