Advanced Editing Tools

Comment/Uncomment
The Comment and Uncomment commands, available from the Tools menu allow you to add or remove comment markers to the selection, or the current line if no text is selected, if comments are supported by the format of the text you are editing.
The rules for how commenting is done are defined in the syntax definitions, so if syntax highlighting is not used, commenting/uncommenting is not possible.
Some formats define single line comment markers, some multiline markers and some both. If multiline markers are not available, commenting out a selection that does not fully include its last line is not possible.
If a single line marker is available, commenting single lines is preferred where applicable, as this helps to avoid problems with nested comments.
When removing comment markers, no uncommented text should be selected. When removing multiline comment markers from a selection, any whitespace outside the comment markers is ignored.
To place comment markers, use the Tools Comment menu item or the related keyboard shortcut sequence, the default is D.
To remove comment markers, use the Tools Uncomment menu item or the related keyboard shortcut, the default is D.

The Editor Component Command Line
's editor component has an internal command line, allowing you to perform various actions from a minimal GUI. The command line is a text entry at the bottom of the editor area; to show it select View Switch to Command Line or use the shortcut (default is F7). The editor provides a set of commands as documented below, and additional commands can be provided by plugins.
To execute a command, type the command then press the return key. The command line will indicate whether it succeeded and possibly display a message. If you entered the command line by pressing F7 it will automatically hide after a few seconds. To clear the message and enter a new command, press F7 again.
The command line has a built-in help system; issue the command help to get started. To see a list of all available commands issue help list; to view help for a specific command, do help command.
The command line has a built in history, so you can reuse commands already typed. To navigate the history, use the Up and Down keys. When showing historical commands, the argument part of the command will be selected, allowing you to easily overwrite the arguments.

Standard Command Line Commands

Argument types
BOOLEAN 	This is used with commands that turns things on or off. Legal values are on, off, true, false, 1 or 0.
INTEGER 	An integer number.
STRING 	A string, surrounded by single quotes (') or double quotes (") when it contains spaces.

Commands for Configuring the Editor
These commands are provided by the editor component, and allow you to configure the active document and view only. This is handy if you want to use a setting different from the default settings, for example for indentation.
set-tab-width INTEGER width
	Sets the tab width to the number width.
set-indent-width INTEGER width
	Sets the indentation width to the number width. Used only if you are indenting with spaces.
set-word-wrap-column INTEGER width
	Sets the line width for hard wrapping to width. This is used if you are having your text wrapped automatically.
set-icon-border BOOLEAN enable
	Sets the visibility of the icon border.
set-folding-markers BOOLEAN enable
	Sets the visibility of the folding markers pane.
set-line-numbers BOOLEAN enable
	Sets the visibility of the line numbers pane.
set-replace-tabs BOOLEAN enable
	If enabled, tabs are replaced with spaces as you type.
set-remove-trailing-space BOOLEAN enable
	If enabled, trailing whitespace is removed whenever the cursor leaves a line.
set-show-tabs BOOLEAN enable
	If enabled, TAB characters and trailing whitespace will be visualized by a small dot.
set-show-indent BOOLEAN enable
	If enabled, indentation will be visualized by a vertical dotted line.
set-indent-spaces BOOLEAN enable
	If enabled, the editor will indent with indent-width spaces for each indentation level, rather than with one TAB character.
set-mixed-indent BOOLEAN enable
	If enabled, will use a mix of TAB and spaces for indentation. Each indentation level will be indent-width wide, and more indentation levels will be optimized to use as many TAB characters as possible.
When executed, this command will additionally set space indentation enabled, and if the indent width is unspecified it will be set to half of the tab-width for the document at the time of execution.
set-word-wrap BOOLEAN enable
	Enables dynamic word wrap according to enable.
set-replace-tabs-save BOOLEAN enable
	When enabled, tabs will be replaced with whitespace whenever the document is saved.
set-remove-trailing-space-save BOOLEAN enable
	When enabled, trailing space will be removed from each line whenever the document is saved.
set-indent-mode STRING name
	Sets the autoindentation mode to name. If name is not known, the mode is set to 'none'. Valid modes are 'none', 'normal', 'cstyle', 'haskell', 'lilypond', 'lisp', 'python', 'ruby' and 'xml'.
set-auto-ident BOOLEAN script
	Enable or disable autoindentation.
set-highlight STRING highlight
	Sets the syntax highlighting system for the document. The argument must be a valid highlight name, as seen in the Tools Highlighting menu. This command provides an autocompletion list for its argument.
reload-scripts
	Reload all JavaScript scripts used by Kate, including indenters and command line scripts.
set-mode STRING mode
	Choose the filetype scheme for the current document.
nn[oremap] STRING original STRING mapped
	Map the key sequence original to mapped.

Commands for editing
These commands modify the current document.
indent
	Indents the selected lines or the current line.
unindent
	Unindents the selected lines or current line.
cleanindent
	Cleans up the indentation of the selected lines or current line according to the indentation settings in the document.
comment
	Inserts comment markers to make the selection or selected lines or current line a comment according to the text format as defined by the syntax highlight definition for the document.
uncomment
	Removes comment markers from the selection or selected lines or current line according to the text format as defined by the syntax highlight definition for the document.
kill-line
	Deletes the current line.
replace STRING pattern STRING replacement
	Replaces text matching pattern with replacement. If you want to include whitespace in the pattern, you must quote both the pattern and replacement with single or double quotes. If the arguments are unquoted, the first word is used as pattern and the rest for replacement. If replacement is empty, each occurrence of pattern is removed.
You can set flags to configure the search by adding a colon, followed by one or more letters each representing a configuration, giving the form replace:options pattern replacement. Available options are:
b 	Search backwards.
c 	Search from cursor position.
e 	Search in the selection only.
r 	Do regular expression search. If set, you may use \N where N is a number to represent captures in the replacement string.
s 	Do case sensitive search.
p 	Prompt for permission to replace the next occurrence.
w 	Match whole words only.
date STRING format
	Inserts a date/time string as defined by the specified format, or the format yyyy-MM-dd hh:mm:ss if none is specified. The following translations are done when interpreting format:
d	The day as number without a leading zero (1-31).
dd	The day as number with a leading zero (01-31).
ddd	The abbreviated localized day name (e.g. 'Mon'..'Sun').
dddd	The long localized day name (e.g. 'Monday'..'Sunday').
M	The month as number without a leading zero (1-12).
MM	The month as number with a leading zero (01-12).
MMMM	The long localized month name (e.g. 'January'..'December').
MMM	The abbreviated localized month name (e.g. 'Jan'..'Dec').
yy	The year as two digit number (00-99).
yyyy	The year as four digit number (1752-8000).
h	The hour without a leading zero (0..23 or 1..12 if AM/PM display).
hh	The hour with a leading zero (00..23 or 01..12 if AM/PM display).
m	The minute without a leading zero (0..59).
mm	The minute with a leading zero (00..59).
s	The second without a leading zero (0..59).
ss	The second with a leading zero (00..59).
z	The milliseconds without leading zeroes (0..999).
zzz	The milliseconds with leading zeroes (000..999).
AP	Use AM/PM display. AP will be replaced by either "AM" or "PM".
ap	Use am/pm display. ap will be replaced by either "am" or "pm".
char STRING identifier
	 This command allows you to insert literal characters by their numerical identifier, in decimal, octal or hexadecimal form. To use it launch the Editing Command dialog and type char: [number] in the entry box, then hit OK.

char examples
Input: char:234
Output: ê
Input: char:0x1234
Output: ሴ
s///[ig] %s///[ig] 	 This command does a sed-like search/replace operation on the current line, or on the whole file (%s///).
In short, the text is searched for text matching the search pattern, the regular expression between the first and the second slash, and when a match is found, the matching part of the text is replaced with the expression between the second and last slash. Parentheses in the search pattern create back references, that is the command remembers which part of the string matched in the parentheses; these strings can be reused in the replace pattern, referred to as \1 for the first set of parentheses, \2 for the second and so on.
To search for a literal ( or ), you need to escape it using a backslash character: \(\)
If you put an i at the end of the expression, the matching will be case insensitive. If you put a g at the end, all occurrences of the pattern will be replaced, otherwise only the first occurrence is replaced.

Replacing text in the current line
Your friendly compiler just stopped, telling you that the class myClass mentioned in line 3902 in your source file is not defined.
"Buckle!" you think, it is of course MyClass. You go to line 3902, and instead of trying to find the word in the text, you launch the Editing Command Dialog, enter s/myclass/MyClass/i, hit the OK button, save the file and compile – successfully without the error.

Replacing text in the whole file
Imagine that you have a file, in which you mention a Miss Jensen several times, when someone comes in and tells you that she just got married to Mr Jones. You want, of course, to replace each and every occurrence of Miss Jensen with Ms Jones.
Enter the command line and issue the command %s/Miss Jensen/Ms Jones/ and hit return, you are done.

A More Advanced Example
This example makes use of back references as well as a character class (if you do not know what that is, please refer to the related documentation mentioned below).
Suppose you have the following line:

void MyClass::DoStringOps( String      &foo, String &bar, String *p, int  &a, int &b )

Now you realize that this is not nice code, and decide that you want to use the const keyword for all address of arguments, those characterized by the & operator in front of the argument name. You would also like to simplify the white space, so that there is only 1 whitespace character between each word.
Launch the Editing Command Dialog, and enter: s/\s+(\w+)\s+(&)/ const \1 \2/g and hit the OK button. The g at the end of the expression makes the regular expression recompile for each match to save the backreferences.
Output: void MyClass::DoStringOps( const String &foo, const String &bar, String *p, const int &a, const int &b )
Mission completed! Now, what happened? Well, we looked for some white space (\s+) followed by one or more alphabetic characters (\w+) followed by some more whitespace (\s+) followed by an ampersand, and in the process saved the alphabetic chunk and the ampersand for reuse in the replace operation. Then we replaced the matching part of our line with one whitespace followed by const followed by one whitespace followed by our saved alphabetical chunk (\1) followed by one whitespace followed by our saved ampersand (\2)
Now in some cases the alphabetical chunk was String, in some int, so using the character class \w and the + quantifier proved a valuable asset.
sort
	Sorts the selected text or entire document.
natsort
	Sort the selected lines or entire document naturally.

sort vs. natsort
sort(a10, a1, a2) results in a1, a10, a2
natsort(a10, a1, a2) results in a1, a2, a10
moveLinesDown
	Move selected lines down.
moveLinesUp
	Move selected lines up.
uniq
	Remove duplicated lines from the selected text or the whole document.
rtrim
	Remove trailing space from the selected text or the whole document.
ltrim
	Remove leading space from the selected text or the whole document.
join STRING separator
	Join selected lines or whole document. Optionally takes a parameter defining a separator, for example: join ', '
rmblank
	Remove all blank spaces from the selected text or the whole document.
unwrap
	Unwrap the selected text or the whole document.
each STRING script
	Given a JavaScript function as an argument, call that for the list of selected lines and replace them with the return value of that callback.

Join selected lines
each 'function(lines){return lines.join(", ")}'
Or, more briefly:
each 'lines.join(", ")'
filter STRING script
	Given a JavaScript function as an argument, call that for the list of selected lines and remove those where the callback returns false.

Remove blank lines
filter 'function(1){return 1.length > 0;}'
Or, more briefly:
filter 'line.length > 0'
map STRING script
	Given a JavaScript function as an argument, call that for the list of selected lines and replace the line with the value of the callback.

Remove blank lines
map 'function(line){return line.replace(/^s+/,"");}'
Or, more briefly:
map 'line.replace(/^s+/,"")'
duplicateLinesUp
	Duplicate the selected lines above the current selection.
duplicateLinesDown
	Duplicate the selected lines below the current selection.

Commands for navigation
goto INT line
	This command navigates to the specified line.
grep STRING pattern
	Search the document for the regular expression pattern. For more information, see
find STRING pattern
	This command navigates to the first occurrence of pattern according to the configuration. Following occurrences can be found using Edit Find Next (the default shortcut is F3).
The find command can be configured by appending a colon followed by one or more options, the form is find:options pattern. The following options are supported:
b 	Search backwards.
c 	Search from cursor position.
e 	Search in the selection only.
r 	Do regular expression search. If set, you may use \N where N is a number to represent captures in the replacement string.
s 	Do case sensitive search.
w 	Match whole words only.
ifind STRING pattern
	This command provides as-you-type searching. You can configure the behavior of the search by appending a colon followed by one or more options, like this: ifind:options pattern. Allowed options are
b 	Search backwards.
r 	Do regular expression search.
s 	Do case sensitive search.
c 	Search from cursor position.

Commands for Basic Editor Functions (These depend on the application the editor component is used in)
w
	Save the current document.
wa
	Save all currently open documents.
q
	Close the current document.
qa
	Close all open documents.
wq
	Save and close the current document.
wqa
	Save and close all currently open documents.
x
	Save and close the current document only if it has changed.
x
	Save and close all currently open documents only if they have changed.
bp
	Go to the previous document in the documents list.
bn
	Go to the next document in the documents list.
new
	Open a new document in horizontal split view.
vnew
	Open a new document in vertical split view.
e
	Reload the current document if it has changed on disk.
enew
	Edit a new document.
print
	Open the Print dialog to print the current document.

Using Code Folding
Code folding allows you to hide parts of a document in the editor, making it easier to overview large documents. In the foldable regions are calculated using rules defined in the syntax highlight definitions, and therefore it is only available in some formats - typically program source code, XML markup and similar. Most highlight definitions supporting code folding also lets you manually define foldable regions, typically using the BEGIN and END keywords.
To use the code folding feature, activate the folding markers using View Show Folding Markers menu item if they are not already visible. The Folding Markers Pane on the left side of the screen displays a graphical view of the foldable regions, with triangle symbols to indicate the possible operation on a given region: a top down triangle means that the region is expanded, clicking it will collapse the region and a right pointing triangle will be displayed instead.
Three commands are provided to manipulate the state of folding regions, see the menu documentation.
The folded lines are remembered when a file is closed, so when you reopen the file the folded nodes will still be folded. This applies to reload operations as well.
If you do not want to use the code folding feature, you can disable the Show folding markers (if available) option in the Appearance page of the editor configuration.