Nvim Session 09: Command-line Mode

:        " Enter command-line mode
<Esc>    " Cancel
<CR>     " Execute

:        " Start
<Up>     " Previous command
<Down>   " Next command
q:       " Open command history window

:wri<Tab>     " Completes to :write
:e ~/at<Tab>  " Completes path
Ctrl-d        " Show all completions

:10          " Go to line 10
:10,20       " Lines 10-20
:.           " Current line
:$           " Last line
:%           " Entire file (same as 1,$)
:'<,'>       " Visual selection

:.,.+5       " Current line and next 5
:.-3,.       " Previous 3 lines to current
:10,+5       " Line 10 to 5 lines below it

:/start/,/end/      " From "start" to "end"
:?function?,/end/   " From previous "function" to next "end"

:10,20d           " Delete lines 10-20
:10,20y           " Yank lines 10-20
:10,20m 0         " Move lines 10-20 to beginning
:10,20t $         " Copy lines 10-20 to end
:.,$d             " Delete from current to end
:1,.-1d           " Delete from start to previous line

:s/old/new/       " First occurrence on current line
:s/old/new/g      " All occurrences on current line
:%s/old/new/g     " All occurrences in file

g     " Global (all matches on line)
c     " Confirm each
i     " Case insensitive
I     " Case sensitive
n     " Count matches (don't replace)
e     " No error if no match

:%s/old/new/gc    " All occurrences, confirm each
:%s/old/new/gi    " Case insensitive
:%s/old/new/gn    " Count matches

:%s/old/new/g     " Literal replacement
:%s/old/\U&/g     " Uppercase match (\U = uppercase, & = match)
:%s/old/\L&/g     " Lowercase match
:%s/\(foo\)/[\1]/g  " Capture group
:%s/old/&_new/g   " Append to match

" Delete trailing whitespace
:%s/\s\+$//g

" Delete blank lines
:g/^$/d

" Convert tabs to spaces
:%s/\t/    /g

" Wrap lines in quotes
:%s/.*/"&"/

" Remove duplicate lines
:sort u

" Add prefix to lines
:%s/^/prefix_/

" Add suffix to lines
:%s/$/_suffix/

:g/pattern/d      " Delete lines matching pattern
:g/ERROR/d        " Delete all ERROR lines
:g/^#/d           " Delete comment lines
:g/^$/d           " Delete blank lines

:g!/pattern/d     " Delete lines NOT matching
:v/pattern/d      " Same (v = inverse)
:v/keep/d         " Keep only lines with "keep"

:g/TODO/t $       " Copy TODO lines to end
:g/FIXME/m 0      " Move FIXME lines to beginning
:g/DEBUG/s//INFO/ " Replace DEBUG with INFO on matching lines
:g/^/m 0          " Reverse file order!

:g/function/p     " Print lines with "function"
:g/error/y A      " Yank (append) error lines to register A
:g/^import/normal A;  " Append semicolon to import lines

" Delete lines between patterns (inclusive)
:g/START/,/END/d

" Operate on lines after match
:g/SECTION/.+1,/SECTION/-1 d

" Indent matching lines
:g/function/normal >>

:!ls             " Run ls, show output
:!date           " Show date
:r !date         " Insert command output
:r !hostname     " Insert hostname

:%!sort          " Sort entire file
:10,20!sort      " Sort lines 10-20
:'<,'>!sort      " Sort visual selection
:%!uniq          " Remove duplicate adjacent lines
:%!tac           " Reverse lines (GNU coreutils)

:%!awk '{print $1}'           " First column only
:%!sed 's/foo/bar/g'          " sed substitute
:10,20!awk '{print NR": "$0}' " Add line numbers
:'<,'>!jq .                   " Format JSON

:w !wc           " Pipe buffer to wc (word count)
:w !cat -n       " Show with line numbers
:'<,'>w !pbcopy  " macOS: copy to clipboard
:'<,'>w !xclip  " Linux: copy to clipboard

:w               " Write file
:w filename      " Write to filename
:w >> filename   " Append to filename
:10,20w filename " Write lines 10-20 to file
:r filename      " Read file into buffer
:e filename      " Edit file
:e!              " Reload, discard changes

:ls              " List buffers
:b N             " Go to buffer N
:bn              " Next buffer
:bp              " Previous buffer
:bd              " Delete buffer
:bufdo %s/old/new/g | w   " Run on all buffers

:sp              " Horizontal split
:vsp             " Vertical split
:sp filename     " Split with file
:only            " Close other windows
:close           " Close current window

:marks           " Show marks
:reg             " Show registers
:delmarks a-z    " Delete marks

:g/TODO/d | w              " Delete TODOs, save
:%s/old/new/g | %s/foo/bar/g   " Multiple substitutes

:%normal A;          " Append ; to every line
:g/function/normal >>   " Indent function lines
:'<,'>normal @a      " Run macro 'a' on selection

" In :commands, you can use expressions
:let @a = 'iHello<Esc>'    " Set register/macro
:@a                        " Execute register

" Convert = to :
:%s/ = /: /g

" Wrap values in quotes
:%s/: \(.*\)/: "\1"/g

" Remove empty values
:g/: ""$/d

" Keep only errors
:v/ERROR/d

" Extract timestamps
:%s/^\([^ ]*\) .*/\1/

" Sort by timestamp
:%!sort