Macos – How to list all installed packages from the command line in bash / osX

Not sure why your script does not work, but my version worked fine. (I suspect it might be the first line):

#! /bin/bash

echo "--> Updating CentOS System"
yum -y update

Remember to chmod 755 the file, and you can just run it with the file name, no need to prepend it with "bash".

I do note that when I tried to reproduce your problem I couldn't (even though your first line is incorrect the script still worked for me). I wonder if there might have been a hidden typo in the key shell line ? Maybe try deleting it and re-adding it.

This has nothing to do with Vim, all editors behave that way (including emacs), they treat non-word characters as delimiters. Anyway, the behavior you are talking about is controlled by readline and its manual lists quite a few commands you can assign shortcuts to. I am pasting a few relevant ones here but I recommend you read man readline for more info:

   backward-word (M-b)
          Move  back  to  the  start  of the current or previous word.  Words 
          are composed of alphanumeric characters (letters and digits).

   kill-line (C-k)
          Kill the text from point to the end of the line.
   kill-word (M-d)
          Kill from point the end of  the  current  word,  or  if  between
          words,  to  the  end  of the next word.  Word boundaries are the
          same as those used by forward-word.
   backward-kill-word (M-Rubout)
          Kill the word behind point.  Word boundaries  are  the  same  as
          those used by backward-word.
   unix-word-rubout (C-w)
          Kill  the  word behind point, using white space as a word bound‐
          ary.  The killed text is saved on the kill-ring.
   unix-filename-rubout
          Kill the word behind point, using  white  space  and  the  slash
          character  as  the word boundaries.  The killed text is saved on
          the kill-ring.

So, the one you want is backward-kill-word, which uses non alphanumeric characters as word boundaries. By default, it is assigned to Alt+Backspace but you can change that by using either the global /etc/inputrc if you want them to apply to all users or (better) your own local $HOME/.inputrc.

As far as I can tell, Ctrl+W seems to be reserved and you can't use that one but you can choose another shortcut, Ctrl+J for example. Create a $HOME/.inputrc file if it doesn't exist and add this line to it:

Control-J: backward-kill-word 

That should be enough for most modern terminal emulators. However, some older terminals use different codes. If you're using xterm, for example, the line above should be written as:

C-J: backward-kill-word