Editors

Every system task ends at an editor — every config file, every script, every fstab, every authorized_keys. Two editors are guaranteed: vi (the POSIX-mandated one — present on every Unix ever) and nano (the kind one). This chapter teaches vi fluency as a survival skill and a fluency, nano as the friendly default, and when each is the right tool.

vi — the one that's always there

Vi's core trick: modes — i to insert, Esc back to normal, where every key is a command. The discipline feels alien for a day, then becomes how you think:

ESC — normal mode (the home base)
i / a / o — insert before / after / new line
:w — write · :q — quit · :wq — save+quit · :q! — force-quit
:x — save+quit · ZZ — save+quit
dd — delete line · yy — yank · p — paste · u — undo · Ctrl-R redo
0 / $ — line start/end · gg / G — file start/end
/pattern — search · n — next · ? — search back
:%s/old/new/g — sed inside the editor
:wq — the command every tutorial drills

The verbs compose: d + motion = delete (dw word, d$ to end, d5d five lines); y + motion = yank; c + motion = change. 5dd deletes five lines; ci" changes inside quotes; v selects visually; . repeats the last command. The language is grammar — verb + motion — and fluency is learning to speak it.

vim — vi's empire

vim adds syntax highlighting, multiple files, splits, plugins — on most Linuxes vi is vim in compatible mode. vimtutor is the built-in tutorial — 20 minutes, genuinely sufficient. The survival set for config work: i/Esc, :wq, dd, u, /, :set number. Everything else is depth.

nano — the kind one

nano file
Ctrl-O — write out · Ctrl-X — exit · Ctrl-W — find
Ctrl-K — cut line · Ctrl-U — uncut · Ctrl-G — help

The shortcuts are printed at the bottom — the editor that explains itself. For quick edits and for anyone not living in the terminal, nano is correct. /etc/alternatives/distro defaults set EDITOR/VISUAL — export EDITOR=nano makes it the system's default (which is what visudo, crontab -e, git commit messages invoke).

vi — the complete grammar

MODES:
  Esc — normal      i/a/o/O — insert     v/V/Ctrl-v — visual     : — ex      R — replace
  Ctrl-o — one normal cmd from insert    gv — reselect last visual

MOTIONS (verb+motion grammar):
  0 $ ^ — line start/end/first-nonblank    w b e — word fwd/back/end    W B E — WORD
  gg G — file start/end    :n / nG — line n    f; F; t; T; — char-target motions
  { } — paragraph    ( ) — sentence    % — matching bracket    * # — word under cursor

VERBS + MOTIONS — the compositional language:
  d — delete    y — yank    c — change    v — select    > — indent    < — dedent    = — reformat
  dd yy cc — line forms    d3w 3dw — delete 3 words    d$ — to end    df; — to the ;
  ci" ca( ciw — inner/around quoted/paren/word    cip — change paragraph
  d/text — to the pattern    yG — to end of file

OPERATORS:
  x — char    X — before    s — substitute char    S — line    J — join lines
  p P — paste after/before    . — REPEAT last command — the superpower    u U Ctrl-R — undo/line/redo
  ~ — swap case    gu gU — lower/upper    r — replace char    zz zt zb — recenter/top/bottom

EX COMMANDS (:):
  :w :q :wq :x :q! ZZ ZQ        — write/quit combos
  :e!                           — revert to disk
  :set number / nonu            — line numbers
  :set paste / nopaste          — the paste-mode fix for bracketed pastes
  :s/old/new/[gc]               — sed inside — % = whole file, g = global, c = confirm
  :g/pat/d                      — delete every matching line — global+cmd
  :v/pat/d                      — delete every NON-matching
  :r file                       — read a file in
  :r! cmd                       — insert a command's output
  :! cmd                        — shell out
  :w !sudo tee %                — save-as-root — the classic fix
  :split :vsplit :tabnew Ctrl-w— splits + tabs
  :noh                          — clear search highlight
  :history :buffers :ls         — the state
  :mark a, 'a                   — named marks
  :registers                    — the yank registers
  :x                            — like :wq but only writes if changed

vim — the additions worth it

vim file +20              # open at line 20
vim file +/pat            # open at first match
vim -R file               # read-only
vim -d a b                # vimdiff — side-by-side diff
vim file1 file2           # multiple — :n :prev :args
vim -o/-O/-p a b          # splits vs tabs
vimtutor                  # the tutorial — run it

:set nu rnu               # absolute + relative numbers — the motion math
:set list                 — show tabs/trailing
:set hlsearch incsearch   — search behavior
:syntax on/off            — highlighting
:retab                    — tabs→spaces per ts
gg=G                      — reindent the whole file
q: q/ q?                  — the command/search history WINDOWS
Ctrl-a Ctrl-x             — inc/dec numbers under cursor

nano — the full set

Ctrl-O write · Ctrl-X exit · Ctrl-W find · Alt-W next · Ctrl-\ replace
Ctrl-K cut · Ctrl-U uncut · Ctrl-Y prev-page · Ctrl-V next-page
Alt-A mark · Alt-6 copy · Ctrl-_ go-to-line · Ctrl-C cursor pos
Ctrl-T spell · Alt-U undo · Alt-E redo · Ctrl-G help
nano -l -c file           # line numbers + cursor pos

ed — the ancestor

ed file
a — append    i — insert    c — change    d — delete
p — print     n — numbered print    ,p — print all    1,5p — lines
/pat/ — search    s/old/new/ — substitute    w — write    q — quit

ed is where sed's s///, vi's : commands, and grep's g/re/p all descend from — the original line editor.

The others worth knowing

• ed — the line editor — ancient, scriptable, the ancestor of sed and vi's : commands — ed survives in POSIX
• sed -i — editing without an editor — sed -i.bak 's/a/b/g' is the scripted edit
• emacs — the other giant — a lisp environment that edits text
• code/nvim/helix — the moderns — VS Code, Neovim, Helix

The config-file craft

Real editing is config work — /etc/fstab, sshd_config, .bashrc:

sudoedit /etc/fstab         # edits as user, writes as root — safer than sudo vi
vi /etc/ssh/sshd_config     # the classic
nano ~/.bashrc

The disciplines: back up before editing (cp file file.bak), learn the file's syntax (comments #, tabs vs spaces where it matters — /etc/fstab whitespace, Makefile tabs), syntax-check after (sshd -t, visudo checks sudoers automatically, mount -a tests fstab). A broken /etc/fstab boots to emergency mode; a broken sudoers locks out sudo — know the check command before saving.

Where editors go wrong

Exercises

1. vimtutor — once through, honestly.
2. Edit a scratch file: dd a line, u undo, /search, :%s/x/y/g.
3. export EDITOR=nano; crontab -e — see the default take effect.
4. sed -i.bak 's/a/b/g' a file — the no-editor edit.
5. Open /etc/fstab in vi — read-only practice, :q! out.

See also

• Shell · Text processing · Core Utilities · Linux