vim Essentials: Editing Without a GUI

On the RHCSA and LFCS exams there is no graphical editor — you edit /etc/fstab, unit files, and SSH configs in vi/vim or not at all. The same is true on most real servers you'll SSH into.

Most editors are always in "insert" mode — every key you press types a character. vim is modal: the same keys do different things depending on the mode you're in. This is why people get stuck: they start typing and vim interprets their letters as commands.

The three modes you need:

• Normal mode — the default when vim opens. Keys are commands: move, delete, copy, paste. You are here whenever you're not sure.
• Insert mode — keys type text, like a normal editor. Enter with i (and friends), leave with Esc.
• Command-line mode — "ex" commands typed at the bottom of the screen, started with : — how you save, quit, and search-and-replace.

To quit, get to Normal mode (Esc), then type one of:

• :q Enter — quit (only works if you haven't made changes)
• :q! Enter — quit and throw away changes. Your panic button.
• :wq Enter — write (save) and quit
• ZZ (Normal mode, no colon) — save and quit; :x is the same idea

If you opened a file by accident and want out with no harm done: Esc :q! Enter. That's it. You are never trapped.

From Normal mode, pick the insert command that puts the cursor where you want:

• i — insert before the cursor · a — append after
• o — open a new line below · O — open a new line above
• A — jump to end of line and insert · I — first non-blank of the line

Moving around (Normal mode):

• h j k l — left, down, up, right (arrows work too)
• w / b — forward/back one word · e — end of word
• 0 — start of line · ^ — first non-blank · $ — end of line
• gg — top of file · G — bottom · 42G or :42 — line 42
• /pattern Enter — jump to next match; n next, N previous

Counts multiply motions: 5j moves down 5 lines, 3w jumps 3 words. This count-plus-motion idea is the heart of vim's speed.

vim's power is combining an operator with a motion — the grammar reads like English:

• d — delete (cut): dw deletes a word, dd a whole line, d$ to end of line, 5dd five lines
• c — change (delete, then Insert mode): cw changes a word
• y — yank (copy): yy copies a line · p/P paste after/before
• x — delete the character under the cursor · r — replace one character
• u — undo · Ctrl-r — redo · . — repeat your last change (hugely useful)

To fix a typo'd word: cursor on it, cw, type the correct word, Esc. To duplicate a line: yy then p.

Substitute (command-line mode) follows :[range]s/old/new/[flags]:

• :s/foo/bar/ — first foo on the current line
• :s/foo/bar/g — all foo on the current line (g = every match on the line)
• :%s/foo/bar/g — all foo in the whole file (% = every line)
• :%s/foo/bar/gc — same, but confirm each change
• :10,20s/foo/bar/g — only lines 10–20

The pattern is a regex, so :%s/ *$// strips trailing spaces from every line. After a substitute, vim reports how many changes on how many lines — read it, it's your sanity check.

• Visual mode: v selects characters, V whole lines, Ctrl-v a block/column (great for columns of config). Then apply an operator (d, y, c).
• Registers: "ayy yanks a line into register a; "ap pastes it — multiple clipboards.
• Macros: qa records into register a, do the edits, q stops; @a replays, 14@a replays 14 times, @@ repeats the last replay. Perfect for repetitive line edits.
• Buffers (multi-file): vim *.env opens several files in one session. :ls lists buffers, :n/:prev walk the argument list, :wa writes all, :wqa writes all and quits. One catch worth knowing before it bites you: :n will not abandon a buffer you have edited but not written — it answers E37: No write since last change. Use :wn (write and next), or :set autowrite once so :n saves for you.

And a minimal ~/.vimrc makes daily editing pleasant (the defaults are exam-sufficient):

The vim Power Tools lesson (vim-power-guide) takes each of these further: marks, filtering through Unix tools, :sort and :g, a vimrc you can verify, windows and tabs, and :argdo across a whole directory.

nano file opens a modeless editor: type to edit, no modes at all. The shortcut bar at the bottom is the whole manual — ^ means Ctrl:

• Ctrl-o Enter — save ("write out") · Ctrl-x — exit
• Ctrl-w — search ("where is") · Ctrl-\ — search & replace
• Ctrl-k / Ctrl-u — cut / paste a line

nano is fine for one-line tweaks. The reasons vim still wins the deep skill investment: it's on every system (vi is guaranteed even on minimal installs; nano isn't), and nothing in nano approaches :%s, macros, or multi-file buffers.