103.8 Basic file editing

Weight: 3

Candidates should be able to edit text files using vi. This objective includes vi navigation, vi modes, inserting, editing, deleting, copying and finding text. It also includes awareness of other common editors and setting the default editor.

Objectives

Navigate a document using vi.
Understand and use vi modes.
Insert, edit, delete, copy and find text in vi.
Awareness of Emacs, nano and vim.
Configure the standard editor.
vi
/, ?
h,j,k,l
i, o, a
d, p, y, dd, yy
ZZ, :w!, :q!
EDITOR

Introduction

As any other tool, we have a wide range of selection when it comes to text editors. One of the most common and super powerful choices is the vi editor. It is pre-installed on all major Linux distributions and you can be sure that knowing it, will let you edit your files on all environments, let it be a remote server over SSH or a coding environment on your desktop machine or a CyberDeck machine with a minimal keyboard. Its only drawback might be its kind of slow learning curve but I'm sure after a 1 hour session with it, you will manage to find your way in vi.

There is an Improved version of vi which is called VIMproved or vim. Sometimes thats what you will find on your system and sometimes the vi command is aliased or linked to vim. Lets check this on our system (Ubuntu 22.04):

jadi@funlife:~$ whatis vi
vi (1)               - Vi IMproved, a programmer's text editor
jadi@funlife:~$ whereis vi
vi: /usr/bin/vi /usr/share/man/man1/vi.1.gz
jadi@funlife:~$ whatis vim
vim (1)              - Vi IMproved, a programmer's text editor
jadi@funlife:~$ whereis vim
vim: /usr/bin/vim /etc/vim /usr/share/vim /usr/share/man/man1/vim.1.gz
jadi@funlife:~$ vi --version
VIM - Vi IMproved 9.0 (2022 Jun 28, compiled Aug 23 2022 20:18:58)
Included patches: 1-242
Modified by team+vim@tracker.debian.org
Compiled by team+vim@tracker.debian.org
Huge version without GUI.  Features included (+) or not (-):
+acl               +file_in_path      +mouse_urxvt       -tag_any_white
+arabic            +find_in_path      +mouse_xterm       -tcl
+autocmd           +float             +multi_byte        +termguicolors
+autochdir         +folding           +multi_lang        +terminal
-autoservername    -footer            -mzscheme          +terminfo
-balloon_eval      +fork()            +netbeans_intg     +termresponse
+balloon_eval_term +gettext           +num64             +textobjects
-browse            -hangul_input      +packages          +textprop
++builtin_terms    +iconv             +path_extra        +timers
+byte_offset       +insert_expand     -perl              +title
+channel           +ipv6              +persistent_undo   -toolbar
+cindent           +job               +popupwin          +user_commands
-clientserver      +jumplist          +postscript        +vartabs
-clipboard         +keymap            +printer           +vertsplit
+cmdline_compl     +lambda            +profile           +vim9script
+cmdline_hist      +langmap           -python            +viminfo
+cmdline_info      +libcall           +python3           +virtualedit
+comments          +linebreak         +quickfix          +visual
+conceal           +lispindent        +reltime           +visualextra
+cryptv            +listcmds          +rightleft         +vreplace
+cscope            +localmap          -ruby              +wildignore
+cursorbind        -lua               +scrollbind        +wildmenu
+cursorshape       +menu              +signs             +windows
+dialog_con        +mksession         +smartindent       +writebackup
+diff              +modify_fname      +sodium            -X11
+digraphs          +mouse             -sound             -xfontset
-dnd               -mouseshape        +spell             -xim
-ebcdic            +mouse_dec         +startuptime       -xpm
+emacs_tags        +mouse_gpm         +statusline        -xsmp
+eval              -mouse_jsbterm     -sun_workshop      -xterm_clipboard
+ex_extra          +mouse_netterm     +syntax            -xterm_save
+extra_search      +mouse_sgr         +tag_binary        
-farsi             -mouse_sysmouse    -tag_old_static    
   system vimrc file: "/etc/vim/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -Wdate-time -g -O2 -ffile-prefix-map=/build/vim-Oy69Mt/vim-9.0.0242=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security -DSYS_VIMRC_FILE=\"/etc/vim/vimrc\" -DSYS_GVIMRC_FILE=\"/etc/vim/gvimrc\" -D_REENTRANT -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 
Linking: gcc -Wl,-Bsymbolic-functions -flto=auto -ffat-lto-objects -flto=auto -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -o vim -lm -ltinfo -lselinux -lsodium -lacl -lattr -lgpm -L/usr/lib/python3.10/config-3.10-x86_64-linux-gnu -lpython3.10 -lcrypt -ldl -lm -lm

To edit a file with vi, just give the file name to it:

$ vi file.txt

vi modes

vi works in two modes:

Command mode is where you go around the file, search, delete text, copy paste, replace, ... and give other commands to the vi. Some commands start with a : and some are only a keypress.
Insert mode is where what you type, goes into the file at the cursors position.

To switch to the Command mode, press the ESC key. To go back to the Insert mode, you can use several commands but one common one is pressing the i key.

Moving the cursor

To move around a text file, use these keys in Command mode:

key	function
h	One character to the left (only current line)
j	One line down
k	One line up
l	One character to the right (only current line)
w	Next word on the current line
e	Next end of word on the current line
b	Previous beginning of the word on the current line
Ctrl-f	Scroll forward one page
Ctrl-b	Scroll backward one page

Typing a number before most commands will repeat the command that many times (i.e. 6h will go 6 characters to the left)

Jumping around

key	function
G	With no number, will jump to the end & 10G will jump to line 10
H	5H will go to the 5th line from the top of the screen
L	3L will move the cursor to the 3rd line to the last line of the screen

Editing text

These command during the command mode will help you enter, edit, replace and text:

key	function
i	Enter the insert mode
a	Enter the insert mode after the current position of the cursor
r	replace only one character
o	open a new line below the cursor and go to the insert mode
O	open a new line above the cursor and go to the insert mode
c	clear to a location and go to the insert mode the replace till there and then normal insert (`cw` will overwrite the current word)
d	delete. you can mix with w (`dw`) to delete a word. Same as cw but dw does not to to the insert mode
dd	Delete the current line
x	Delete character at the position of the cursor
p	Paste the last deleted text after the cursor
P	Paste the last deleted text before the cursor
xp	swaps the character at the cursor position with the one on its right

Searching

key	function
/	Search forward (`/happiness` will find the next happiness)
?	Search backward
n	repeat previous search. You can also use `/` and `?` without any parameters)

Search wraps around to the top once the bottom of file is reached

Exiting

It is always funny when you see someone entering to the vi and not knowing how to exit! Learn these and prevent the laughter:

key	function
:q!	Quit editing without saving = runaway after any mistake
:w!	Write the file (whether modified or not). Attempt to overwrite existing files or read-only or other unwritable files
:w myfile.txt	Write to a new name
ZZ	Exit and save the file if modified
:e!	Reload the file from disk
:!	Run a shell command

Entering colon (:) during command mode will move the cursor to the bottom of the screen and vi will wait for your commands. Press ESC to return back to the normal command mode.

The exclamation mark in most commands will say "I know what I'm doing" and will write on read-only files if you have access and will exit without asking

it is possible to combine commands. For example you can combine :w and :q and just say :wq (write and exit).

help

You can always ask for help with :help or :help subject. This way vi will open a help text which you can use / search just like any other text. Close it with :q command.

Other editors

You can also use other editors if you want. One easy to use and common option is nano and some other choices are micro, emacs (full featured) and neovim (an update to vim).

Default editor

The default editor in bash is set using the EDITOR environment variable. You can change it with:

$ export EDITOR='vim'

or by adding the above line to the .bashrc file. We will see these in more details in next chapters.

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