[CALUG] vi

Tue Nov 22 10:47:50 CST 2005

Hey, if you like vi, you'll love sed

It lets you do your editing in batch mode, without even having to look at the file you are changing.

> also try running vimtutor. its a nice little walkthrough of all the basics.
> --Jason
> 
> On 11/22/05, Rick Radzville <rradzville at hotmail.com> wrote:
> > Jim,
> >
> > Thank you very much for such an awesome intro to vi. I'm approaching Linux
> > from a sysadmin point of view, where the main question is always "What task
> > that I need to do can I accomplish with this?" And your lesson illustrates
> > that very effectively.
> >
> > v/r,
> > Rick
> >
> >
> > >From: Jim Sansing <jjsansing at comcast.net>
> > >To: Rick Radzville <rradzville at hotmail.com>
> > >Subject: Re: [CALUG] Best programming app
> > >Date: Mon, 21 Nov 2005 19:19:20 -0500
> > >
> > >Rick,
> > >
> > >To answer your question, I am not talking about a database.  But the data
> > >could be a directory listing, an html file, or a C program.
> > >
> > >NOTE: In the following examples, type what is in the single quotes, but
> > >not the single quotes themselves.
> > >
> > >The key to learning vi is to understand the difference between command
> > >mode and
> > >input mode.  Input mode is what you are used to in most editors/word
> > >processors,
> > >you type and the characters are added to the working copy of the file.
> > >When you
> > >start vi, you are in command mode.  Type 'i' and you are in input mode.
> > >Start
> > >typing.  To get out of input mode, press ESC.
> > >
> > >Command mode allows you to operate on the characters indirectly.  Cut
> > >and paste
> > >is an example of this.  You select a block, copy it to the clipboard,
> > >and paste it to
> > >the destination.  In vi, copy is "y" for yank.  In order to be able to
> > >yank what you
> > >want, you need to know some navigation commands.  Note that current line
> > >is the
> > >line where the cursor is.  You have to learn vi by doing, so vi a file
> > >and move the
> > >cursor to the middle of a line and press '0', then press '$'.  You'll
> > >get the idea.
> > >Oh, and to get out without saving the changes, press ESC, then type
> > >':q!' and
> > >press Enter.  (Some people press Ctrl-Z, but that leaves the recovery
> > >file on
> > >Linux which is confusing the next time you edit that file.)
> > >
> > >0 / $ = Start / End of the current line
> > >( / ) = Beginning of / Next  sentence (identified by a period)
> > >{ / } = Beginning / End of a paragraph
> > >% = Corresponding paren, bracket, or brace
> > >
> > >So, now to yank from the cursor to the end of the line, type 'y$'.  Now
> > >use the
> > >arrow keys to move to a blank line and press 'p' for put.
> > >
> > >Now move to the beginning of a paragraph by typing '{'.  Type 'y}' and
> > >then 'P'.
> > >
> > >Now type '3y}' and then 'P'.  You have just cut and pasted 3 paragraphs.
> > >
> > >OK, so cut and paste isn't very exciting.  But you have to walk before
> > >you run.
> > >
> > >The next thing is substitute, or Find and Replace.  You have to work on
> > >the vi
> > >command line for this.  Press ':' and the cursor moves to the bottom of
> > >the screen.
> > >Type '1,$ s/a/@/g' and press Enter.  Every lowercase a in your file just
> > >changed
> > >to @.  Press 'u' to undo that.
> > >
> > >Now type ':1,11 s/^...//' and press Enter.  You have just deleted the
> > >1st 3 characters
> > >of the first 11 lines in your file.  (Again press 'u' to undo it).
> > >
> > >Now type ':1,$ s/^$/---/' and press Enter.  You have just turned every
> > >blank line
> > >into a line with 3 dashes.
> > >
> > >Now type ':1,$ s/[0-9]/#/g' and press Enter.  You have just turned every
> > >number
> > >in your file into a # sign.
> > >
> > >Now do a search by typing '/...e' and press Enter.  To change from the
> > >cursor to
> > >the end of the word and the next word, type '2cwXXX' and press ESC.  Now
> > >press 'n' to find the next instance of any 3 characters preceeding an e,
> > >and press '.'
> > >to repeat the change command.
> > >
> > >NOTE:  Period in a search is the single character wildcard.  So 'p.t'
> > >finds pat,
> > >pet, pit, pot, prt, and put.  Period in command mode repeats the last
> > >text modify
> > >command.  So if you did a yank and put, it will put the yanked data again.
> > >
> > >Now exit your file.  Here is a trivial example of building a shell
> > >script.  Enter
> > >'ls > foo; ls >> foo; sort foo > bar; rm foo; vi bar' on the bash
> > >command line.
> > >You should see 2 lines of each of your files.
> > >
> > >On the 1st line press 'J'.  This joins the 1st and 2nd line.  Now press
> > >Enter and '.'
> > >until you have joined all of the lines and every line has 2 copies of a
> > >filename.
> > >
> > >Type ':1,$ s" " foo/"' and press Enter.  (In case you are having trouble
> > >reading this,
> > >it is: s<double_quote><space><double_quote><space>foo<slash><double_quote>.
> > >You do this because the standard seperator charactor, '/' is part of the
> > >substitution
> > >string.  I have heard that any seperator charactor will do, but I
> > >haven't tested it.
> > >
> > >Now type ':1,$ s/^/cp /' and press Enter.
> > >
> > >Now type 1G to go to the top of the file.  Press 'O' to go into input
> > >mode on the
> > >line before the cursor (open a new line) and type:
> > >
> > >#!/bin/sh
> > >#
> > >mkdir foo
> > >
> > >Press ESC, and type ':wq' to save your file, bar.  Now, from the bash
> > >command
> > >line, enter 'chmod 700 bar' to make the bar file executable.  Enter 'ls
> > >-l bar' to
> > >see the permissions.  Now enter './bar'.  Now enter 'ls temp'. To get
> > >rid of the
> > >temp directory, enter 'rm -r foo'.
> > >
> > >Like I said, this is a trivial example.  But I have created shell
> > >scripts that do the
> > >following on over 100 files just as easily:
> > >
> > >grep foo file | tr -s ' ' | cut -f1,3-5,7 -d' ' > file.temp
> > >
> > >This will find every line that has the characters foo in it in each
> > >file, turn multiple
> > >spaces into a single space, get the 1st, 3rd, 4th, 5th, and 7th space
> > >seperated fields,
> > >and write that to the same file with a .temp extension.  It might take a
> > >few minutes
> > >to run, but it beats hours of trying to use cut and paste to get only
> > >those fields.
> > >
> > >And when it comes to editing C code, vi has lots of nice features like
> > >verifying
> > >that your parens, brackets, and braces are closed, color coding reserved
> > >words,
> > >you can even set it to automatically complete things like for conditions or
> > >if/else statements.
> > >
> > >So, that's why I call vi powerful.  I highly recommend 'Learning the Vi
> > >editor' from
> > >O'Reilly.  It not only covers vi, it also discusses the variants like
> > >vim and what they
> > >add to basic vi.
> > >
> > >Later . . .   Jim
> > >
> > >
> > >
> > >Rick Radzville wrote:
> > > >Wow. I'm an expert microsoftie, linux newbie. This comment is the reason
> > >why
> > > >I'm experimenting w/Linux. Jim, would you mind sharing a few more
> > >details?
> > > >When you refer to "data", are you talking about "a listing of the
> > > >directories & files on the user's PC" or "a database"?
> > > >v/r,
> > > >Rick Radzville
> > > >
> > > >
> >
> >
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