dte text editor

dterc

dterc is the language used in dte configuration files (~/.dte/rc) and also in the command mode of the editor (Alt+x). The syntax of the language is quite similar to shell, but much simpler.

Commands are separated either by a newline or ; character. To make a command span multiple lines in an rc file, escape the newline (put \ at the end of the line).

Rc files can contain comments at the start of a line. Comments begin with a # character and can be indented, but they can't be put on the same line as a command.

Commands can contain environment variables. Variables always expand into a single argument even if they contain whitespace. Variables inside single or double quotes are NOT expanded. This makes it possible to bind keys to commands that contain variables (inside single or double quotes), which will be expanded just before the command is executed.

Example:

alias x "run chmod 755 $FILE"

$FILE is expanded when the alias x is executed. The command works even if $FILE contains whitespace.

Special variables

These variables are always defined and override environment variables of the same name.

$FILE

The filename of the current buffer (or an empty string if unsaved).

$FILETYPE

The value of the filetype option for the current buffer.

$WORD

The selected text or the word under the cursor.

Single quoted strings

Single quoted strings can't contain single quotes or escaped characters.

Double quoted strings

Double quoted strings may contain the following escapes:

\a, \b, \t, \n, \v, \f, \r
Control characters (same as in C)
\\
Escaped backslash
\x0a
Hexadecimal byte value 0x0a. Note that \x00 is not supported because strings are NUL-terminated.
\u20ac
Four hex digit Unicode code point U+20AC.
\U000020ac
Eight hex digit Unicode code point U+20AC.

Commands

Configuration Commands

Configuration commands are used to customize certain aspects of the editor, for example adding key bindings, setting options, etc. These are the only commands allowed in user config files.

alias name command

Create an alias name for command.

Example:

alias read 'pipe-from cat'

Now you can run read file.txt to insert file.txt into the current buffer.

bind key [command]

Bind command to key. If no command is given then any existing binding for key is removed.

Special keys:

Modifiers:

Ctrl:
C-X or ^X
Alt:
M-X
Shift:
S-left

set [-gl] option [value] ...

Set value for option. Value can be omitted for boolean option to set it true. Multiple options can be set at once but then value must be given for every option.

There are three kinds of options.

  1. Global options.

  2. Local options. These are file specific options. Each open file has its own copies of the option values.

  3. Options that have both global and local values. The Global value is just a default local value for opened files and is never used for anything else. Changing the global value does not affect any already opened files.

By default set changes both global and local values.

-g
Change only global option value
-l
Change only local option value of current file

In configuration files only global options can be set (no need to specify the -g flag).

To automatically set options for specific filetypes and filenames use the option command.

setenv name value

Set environment variable.

hi name [fg-color [bg-color]] [attribute]...

Set highlight color.

The name argument can be a token name defined by a dte-syntax file or one of the following, built-in highlight names:

The fg-color and bg-color arguments can be one of the following:

Colors 16 to 231 correspond to R/G/B colors. Colors 232 to 255 are grayscale values.

If the terminal has limited support for rendering colors, the fg-color and bg-color arguments will fall back to the nearest supported color, which may be less precise than the value specified.

The attribute argument(s) can be any combination of the following:

The color and attribute value keep is useful in selected text to keep fg-color and attributes and change only bg-color.

NOTE: Because keep is both a color and an attribute you need to specify both fg-color and bg-color if you want to set the keep attribute.

Unset fg/bg colors are inherited from highlight color default. If you don't set fg/bg for the highlight color default then terminal's default fg/bg is used.

ft [-bcfi] filetype string...

Add a filetype association. Filetypes are used to determine which syntax highlighter and local options to use when opening files.

By default string is interpreted as one or more filename extensions.

-b
Interpret string as a file basename
-c
Interpret string as a regex pattern and match against the contents of the first line of the file
-f
Interpret string as a regex pattern and match against the full (absolute) filename
-i
Interpret string as a command interpretter name and match against the Unix shebang line (after removing any path prefix and/or version suffix)

Examples:

ft c c h
ft -b make Makefile GNUmakefile
ft -c xml '<\?xml'
ft -f mail '/tmpmsg-.*\.txt$'
ft -i lua lua luajit

See also:

option [-r] filetype option value...

Add automatic option for filetype (as previously registered with the ft command). Automatic options are set when files are are opened.

-r
Interpret filetype argument as a regex pattern instead of a filetype and match against full filenames

include [-b] file

Read and execute commands from file.

-b
Read built-in file instead of reading from the filesystem

Note: "built-in files" are config files bundled into the program binary. See the -B and -b flags in the dte man page for more information.

errorfmt [-i] compiler regexp [file|line|column|message]...

-i
Ignore this error

See compile and msg commands for more information.

load-syntax filename|filetype

Load a dte-syntax file into the editor. If the argument contains a / character it's considered a filename.

Note: this command only loads a syntax file ready for later use. To actually apply a syntax highlighter to the current buffer, use the set command to change the filetype of the buffer instead, e.g. set filetype html.

Editor Commands

quit [-fp]

Quit the editor.

-f
Force quit, even if there are unsaved files
-p
Prompt for confirmation if there are unsaved files

suspend

Suspend the editor (run fg in the shell to resume).

cd directory

Change the working directory and update $PWD and $OLDPWD. Running cd - changes to the previous directory ($OLDPWD).

command [text]

Enter command mode. If text is given then it is written to the command line (see the default ^L key binding for why this is useful).

search [-Hnprw] [pattern]

If no flags or just -r and no pattern given then dte changes to search mode where you can type a regular expression to search.

-H
Don't add pattern to search history
-n
Search next
-p
Search previous
-r
Start searching backwards
-w
Search word under cursor

git-open

Interactive file opener. Lists all files in a git repository.

Same keys work as in command mode, but with these changes:

up
Move up in file list.
down
Move down in file list.
enter
Open file.
^O
Open file but don't close git-open.
M-e
Go to end of file list.
M-t
Go to top of file list.

refresh

Trigger a full redraw of the screen.

Buffer Management Commands

open [-g] [-e encoding] [filename]...

Open file. If filename is omitted, a new file is opened.

-e encoding
Set file encoding. See iconv -l for list of supported encodings.
-g
Perform glob expansion on filename.

save [-dfup] [-e encoding] [filename]

Save file. By default line-endings (LF vs CRLF) are preserved.

-d
Save with DOS/CRLF line-endings
-f
Force saving read-only file
-u
Save with Unix/LF line-endings
-p
Open a command prompt if there's no specified or existing filename
-e encoding
Set file encoding. See iconv -l for list of supported encodings.

close [-fqw]

Close file.

-f
Close file even if it hasn't been saved after last modification
-q
Quit if closing the last open file
-w
Close parent window if closing its last contained file

next

Display next file.

prev

Display previous file.

view N|last

Display _N_th or last open file.

move-tab N|left|right

Move current tab to position N or 1 position left or right.

Window Management Commands

wsplit [-bhr] [file]...

Like open but at first splits current window vertically.

-b
Add new window before current instead of after.
-h
Split horizontally instead of vertically.
-r
Split root instead of current window.

wclose [-f]

Close window.

-f
Close even if there are unsaved files in the window

wnext

Next window.

wprev

Previous window.

wresize [-hv] [N|+N|-- -N]

If no parameter given, equalize window sizes in current frame.

-h
Resize horizontally
-v
Resize vertically
N
Set size of current window to N characters.
+N
Increase size of current window by N characters.
-N
Decrease size of current window by N characters. Use -- to prevent the minus symbol being parsed as an option flag, e.g. wresize -- -5.

wflip

Change from vertical layout to horizontal and vice versa.

wswap

Swap positions of this and next frame.

Movement Commands

left [-c]

Move left.

-c
Select characters

right [-c]

Move right.

-c
Select characters

up [-cl]

Move cursor up.

-c
Select characters
-l
Select whole lines

down [-cl]

Move cursor down.

-c
Select characters
-l
Select whole lines

pgup [-cl]

Move cursor page up. See also scroll-pgup.

-c
Select characters
-l
Select whole lines

pgdown [-cl]

Move cursor page down. See also scroll-pgdown.

-c
Select characters
-l
Select whole lines

word-fwd [-cs]

Move cursor forward one word.

-c
Select characters
-s
Skip special characters

word-bwd [-cs]

Move cursor backward one word.

-c
Select characters
-s
Skip special characters

bol [-cs]

Move to beginning of line.

-c
Select characters
-s
Move to beginning of indented text or beginning of line, depending on current cursor position.

eol [-c]

Move cursor to end of line.

-c
Select characters

bof

Move to beginning of file.

eof

Move cursor to end of file.

bolsf

Incrementally move cursor to beginning of line, then beginning of screen, then beginning of file.

eolsf

Incrementally move cursor to end of line, then end of screen, then end of file.

scroll-up

Scroll view up one line. Keeps cursor position unchanged if possible.

scroll-down

Scroll view down one line. Keeps cursor position unchanged if possible.

scroll-pgup

Scroll page up. Cursor position relative to top of screen is maintained. See also pgup.

scroll-pgdown

Scroll page down. Cursor position relative to top of screen is maintained. See also pgdown.

center-view

Center view to cursor.

line number

Go to line.

tag [-r] [tag]

Save current location to stack and go to the location of tag. Requires tags file generated by Exuberant Ctags. If no tag is given then word under cursor is used as a tag instead.

-r
return back to previous location

Tag files are searched from current working directory and its parent directories.

See also msg command.

msg [-np]

Show latest, next (-n) or previous (-p) message. If its location is known (compile error or tag message) then the file will be opened and cursor moved to the location.

-n
Next message
-p
Previous message

See also compile and tag commands.

Editing Commands

cut

Cut current line or selection.

copy [-k]

Copy current line or selection.

-k
Keep selection (by default, selections are lost after copying)

paste [-c]

Paste text previously copied by the copy or cut commands.

-c
Paste at the cursor position

undo

Undo latest change.

redo [choice]

Redo changes done by the undo command. If there are multiple possibilities a message is displayed:

Redoing newest (2) of 2 possible changes.

If the change was not the one you wanted, just run undo and then, for example, redo 1.

clear

Clear current line.

join

Join selection or next line to current.

new-line

Insert empty line under current line.

delete

Delete character after cursor (or selection).

erase

Delete character before cursor (or selection).

delete-eol [-n]

Delete to end of line.

-n
Delete newline if cursor is at end of line

erase-bol

Erase to beginning of line.

delete-word [-s]

Delete word after cursor.

-s
Be more "aggressive"

erase-word [-s]

Erase word before cursor.

-s
Be more "aggressive"

case [-lu]

Change text case. The default is to change lower case to upper case and vice versa.

-l
Lower case
-u
Upper case

insert [-km] text

Insert text into the buffer.

-k
Insert one character at a time as if it has been typed
-m
Move after inserted text

replace [-bcgi] pattern replacement

Replace all instances of text matching pattern with the replacement text.

The pattern is a POSIX extended regex(7).

-b
Use basic instead of extended regex syntax
-c
Ask for confirmation before each replacement
-g
Replace all matches for each line (instead of just the first)
-i
Ignore case

shift count

Shift current or selected lines by count indentation levels. Count is usually -1 (decrease indent) or 1 (increase indent).

To specify a negative number, it's necessary to first disable option parsing with --, e.g. shift -- -1.

wrap-paragraph [width]

Format the current selection or paragraph under the cursor. If paragraph width is not given then the text-width option is used.

This command merges the selection into one paragraph. To format multiple paragraphs use the external fmt(1) program with the filter command, e.g. filter fmt -w 60.

select [-bkl]

Enter selection mode. All movement commands while in this mode extend the selected area.

Note: A better way to create selections is to hold the Shift key whilst moving the cursor. The select command exists mostly as a fallback, for terminals with limited key binding support.

-b
Select block between opening { and closing } curly braces
-k
Keep existing selections
-l
Select whole lines

unselect

Unselect.

External Commands

filter command [parameter]...

Filter selected text or whole file through external command.

Example:

filter sort -r

Note that command is executed directly using execvp. To use shell features like pipes or redirection, use a shell interpreter as the command. For example:

filter sh -c 'tr a-z A-Z | sed s/foo/bar/'

pipe-from [-ms] command [parameter]...

Run external command and insert its standard output.

-m
Move after the inserted text
-s
Strip newline from end of output

pipe-to command [parameter]...

Run external command and pipe the selected text (or whole file) to its standard input.

Can be used to e.g. write text to the system clipboard:

pipe-to xsel -b

run [-ps] command [parameters]...

Run external command.

-p
Display "Press any key to continue" prompt
-s
Silent -- both stderr and stdout are redirected to /dev/null

compile [-1ps] errorfmt command [parameters]...

Run external command and collect output messages. This can be used to run e.g. compilers, build systems, code search utilities, etc. and then jump to a file/line position for each message.

The errorfmt argument corresponds to a regex capture pattern previously specified by the errorfmt command. After command exits successfully, parsed messages can be navigated using the msg command.

-1
Read error messages from stdout instead of stderr
-p
Display "Press any key to continue" prompt
-s
Silent. Both stderr and stdout are redirected to /dev/null

See also: errorfmt and msg commands.

eval command [parameter]...

Run external command and execute its standard output text as dterc commands.

Other Commands

repeat count command [parameters]...

Run command count times.

toggle [-gv] option [values]...

Toggle option. If list of values is not given then the option must be either boolean or enum.

-g
toggle global option instead of local
-v
display new value

If option has both local and global values then local is toggled unless -g is used.

Options

Options can be changed using the set command. Enumerated options can also be toggled. To see which options are enumerated, type "toggle " in command mode and press the tab key. You can also use the option command to set default options for specific file types.

Global options

case-sensitive-search [true]

false
Search is case-insensitive.
true
Search is case-sensitive.
auto
If search string contains an uppercase letter search is case-sensitive, otherwise it is case-insensitive.

display-invisible [false]

Display invisible characters.

display-special [false]

Display special characters.

esc-timeout [100] 0...2000

When single escape is read from the terminal dte waits some time before treating the escape as a single keypress. The timeout value is in milliseconds.

Too long timeout makes escape key feel slow and too small timeout can cause escape sequences of for example arrow keys to be split and treated as multiple key presses.

filesize-limit [250]

Refuse to open any file with a size larger than this value (in mebibytes). Useful to prevent accidentally opening very large files, which can take a long time on some systems.

lock-files [true]

Lock files using $DTE_HOME/file-locks. Only protects from your own mistakes (two processes editing same file).

newline [unix]

Whether to use LF (unix) or CRLF (dos) line-endings. This is just a default value for new files.

scroll-margin [0]

Minimum number of lines to keep visible before and after cursor.

set-window-title [false]

Set the window title to the filename of the current buffer (if the terminal supports it).

show-line-numbers [false]

Show line numbers.

statusline-left [" %f%s%m%r%s%M"]

Format string for the left aligned part of status line.

%f
Filename.
%m
Prints * if file is has been modified since last save.
%r
Prints RO if file is read-only.
%y
Cursor row.
%Y
Total rows in file.
%x
Cursor display column.
%X
Cursor column as characters. If it differs from cursor display column then both are shown (e.g. 2-9).
%p
Position in percentage.
%E
File encoding.
%M
Miscellaneous status information.
%n
Line-ending (LF or CRLF).
%s
Add separator.
%t
File type.
%u
Hexadecimal Unicode value value of character under cursor.
%%
Literal %.

statusline-right [" %y,%X %u %E %n %t %p "]

Format string for the right aligned part of status line.

tab-bar [horizontal]

hidden
Hide tab bar.
horizontal
Show tab bar on top.
vertical
Show tab bar on left if there's enough space, hide otherwise.
auto
Show tab bar on left if there's enough space, on top otherwise.

tab-bar-max-components [0]

Maximum number of path components displayed in vertical tab bar. Set to 0 to disable.

tab-bar-width [25]

Width of vertical tab bar. Note that width of tab bar is automatically reduced to keep editing area at least 80 characters wide. Vertical tab bar is shown only if there's enough space.

Local options

brace-indent [false]

Scan for { and } characters when calculating indentation size. Depends on the auto-indent option.

filetype [none]

Type of file. Value must be previously registered using the ft command.

indent-regex [""]

If this regular expression matches current line when enter is pressed and auto-indent is true then indentation is increased. Set to "" to disable.

Local and global options

The global values for these options serve as the default values for local (per-file) options.

auto-indent [true]

Automatically insert indentation when pressing enter. Indentation is copied from previous non-empty line. If also the indent-regex local option is set then indentation is automatically increased if the regular expression matches current line.

detect-indent [""]

Comma-separated list of indent widths (1-8) to detect automatically when a file is opened. Set to "" to disable. Tab indentation is detected if the value is not "". Adjusts the following options if indentation style is detected: emulate-tab, expand-tab, indent-width.

Example:

set detect-indent 2,3,4,8

emulate-tab [false]

Make delete, erase and moving left and right inside indentation feel as if there were tabs instead of spaces.

expand-tab [false]

Convert tab to spaces on insert.

file-history [true]

Save line and column for each file to $DTE_HOME/file-history.

indent-width [8]

Size of indentation in spaces.

syntax [true]

Use syntax highlighting.

tab-width [8]

Width of tab. Recommended value is 8. If you use other indentation size than 8 you should use spaces to indent.

text-width [72]

Preferred width of text. Used as the default argument for the wrap-paragraph command.

ws-error [special]

Comma-separated list of flags that describe which whitespace errors should be highlighted. Set to "" to disable.

auto-indent
If the expand-tab option is enabled then this is the same as tab-after-indent,tab-indent. Otherwise it's the same as space-indent.
space-align
Highlight spaces used for alignment after tab indents as errors.
space-indent
Highlight space indents as errors. Note that this still allows using less than tab-width spaces at the end of indentation for alignment.
tab-after-indent
Highlight tabs used anywhere other than indentation as errors.
tab-indent
Highlight tabs in indentation as errors. If you set this you most likely want to set "tab-after-indent" too.
special
Display all characters that look like regular space as errors. One of these characters is no-break space (U+00A0), which is often accidentally typed (AltGr+space in some keyboard layouts).
trailing
Highlight trailing whitespace characters at the end of lines as errors.