nano/doc/nano.texi

\input texinfo  @c -*-texinfo-*-
@c %**start of header
@setfilename nano.info
@settitle nano
@c %**end of header

@documentencoding UTF-8

@smallbook
@set EDITION 0.5
@set VERSION 5.4
@set UPDATED December 2020

@dircategory Editors
@direntry
* nano: (nano).                 Small and friendly text editor.
@end direntry

@c tex
@c \overfullrule=0pt
@c end tex

@titlepage
@title GNU @command{nano}
@subtitle a small and friendly text editor
@subtitle version 5.4

@author Chris Allegretta
@page

This manual documents the GNU @command{nano} editor.
@sp 1
This manual is part of the GNU @command{nano} distribution.@*

@sp 4
Copyright @copyright{} 1999-2009, 2014-2020 Free Software Foundation, Inc.

@sp 1
This document is dual-licensed.  You may distribute and/or modify it
under the terms of either of the following licenses:

@sp 1
* The GNU General Public License, as published by the Free Software
  Foundation, version 3 or (at your option) any later version.  You
  should have received a copy of the GNU General Public License along
  with this program.  If not, see @url{https://www.gnu.org/licenses/}.

@sp 1
* The GNU Free Documentation License, as published by the Free Software
  Foundation, version 1.2 or (at your option) any later version, with no
  Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
  You should have received a copy of the GNU Free Documentation License
  along with this program.  If not, see @url{https://www.gnu.org/licenses/}.

@sp 1
You may contact the author by
e-mail: @email{chrisa@@asty.org}@*
@end titlepage

@ifnottex


@node Top
@top

This manual documents the GNU @command{nano} editor, version 5.4.

@menu
* Introduction::
* Invoking::
* Command-line Options::
* Editor Basics::
* Built-in Help::
* The File Browser::
* Feature Toggles::
* Nanorc Files::
* Pico Compatibility::
* Building and Configure Options::
@end menu

@end ifnottex


@node Introduction
@chapter Introduction

GNU @command{nano} is a small and friendly text editor.  Besides
basic text editing, @command{nano} offers features like undo/redo,
syntax coloring, interactive search-and-replace, auto-indentation,
line numbers, word completion, file locking, backup files, and
internationalization support.

The original goal for @command{nano} was to be a complete bug-for-bug
emulation of Pico.  But currently the goal is to be as compatible
as is reasonable while offering a superset of Pico's functionality.
@xref{Pico Compatibility} for more details on how @command{nano} and
Pico differ.

Starting with version 4.0, @command{nano} no longer hard-wraps an overlong
line by default.  It further uses linewise scrolling by default, and by
default includes the line below the title bar into the editing area.
If you want the old, Pico behavior back, you can use the
following options: @option{--breaklonglines},
@option{--jumpyscrolling}, and @option{--emptyline}
(or @option{-bje}).

Please report bugs via @url{https://savannah.gnu.org/bugs/?group=nano}.

For background information see @url{https://nano-editor.org/}.

@node Invoking
@chapter Invoking

The usual way to invoke @command{nano} is:

@iftex
@sp 1
@end iftex
@example
@code{nano [FILE]}
@end example
@iftex
@sp 1
@end iftex

But it is also possible to specify one or more options (see the next
section), and to edit several files in a row.  Additionally, the cursor
can be put on a specific line of a file by adding the line number
with a plus sign before the filename, and even in a specific column by
adding it with a comma.
(Negative numbers count from the end of the file or line.)
The cursor can also be put on the first or last occurrence of a specific string
by specifying that string after @code{+/} or @code{+?} before the filename.
The string can be made case sensitive and/or caused to be interpreted as a
regular expression by inserting a @code{c} and/or @code{r} after the plus sign.
These search modes can be explicitly disabled by using the uppercase variant
of those letters: @code{C} and/or @code{R}.  When the string contains spaces,
it needs to be enclosed in quotes.
A more complete command synopsis thus is:

@iftex
@sp 1
@end iftex
@example
@code{nano [OPTION]@dots{} [[+LINE[,COLUMN]|+[crCR](/|?)STRING] FILE]@dots{}}
@end example
@iftex
@sp 1
@end iftex

Normally, however, you set your preferred options in a @file{nanorc}
file (@pxref{Nanorc Files}).  And when using @code{set positionlog}
(making @command{nano} remember the cursor position when you close a file),
you will rarely need to specify a line number.

As a special case: when instead of a filename a dash is given, @command{nano}
will read data from standard input.  This means you can pipe the output of
a command straight into a buffer, and then edit it.


@node Command-line Options
@chapter Command-line Options

@command{nano} takes the following options from the command line:

@table @option

@item -A
@itemx --smarthome
Make the Home key smarter.  When Home is pressed anywhere but at the
very beginning of non-whitespace characters on a line, the cursor will
jump to that beginning (either forwards or backwards).  If the cursor is
already at that position, it will jump to the true beginning of the
line.

@item -B
@itemx --backup
When saving a file, back up the previous version of it, using the current
filename suffixed with a tilde (@code{~}).

@item -C @var{directory}
@itemx --backupdir=@var{directory}
Make and keep not just one backup file, but make and keep a uniquely
numbered one every time a file is saved --- when backups are enabled.
The uniquely numbered files are stored in the specified directory.

@item -D
@itemx --boldtext
For the interface, use bold instead of reverse video.  This will be overridden
by setting the options @code{titlecolor}, @code{statuscolor}, @code{keycolor},
@code{functioncolor}, @code{numbercolor}, and/or @code{selectedcolor} in your
nanorc file.  @xref{@code{set functioncolor}} for details.

@item -E
@itemx --tabstospaces
Convert typed tabs to spaces.

@item -F
@itemx --multibuffer
Read a file into a new buffer by default.

@item -G
@itemx --locking
Enable vim-style file locking when editing files.

@item -H
@itemx --historylog
Save the last hundred search strings and replacement strings and
executed commands, so they can be easily reused in later sessions.

@item -I
@itemx --ignorercfiles
Don't look at the system's nanorc file nor at the user's nanorc.

@item -J
@itemx --guidestripe
Draw a vertical stripe at the given column, to help judge the width of the
text.  (The color of the stripe can be changed with @code{set stripecolor}
in your nanorc file.)

@item -K
@itemx --rawsequences
Interpret escape sequences directly (instead of asking @code{ncurses} to
translate them).  If you need this option to get your keyboard to work
properly, please report a bug.  Using this option disables @command{nano}'s
mouse support.

@item -L
@itemx --nonewlines
Don't automatically add a newline when a text does not end with one.
(This can cause you to save non-POSIX text files.)

@item -M
@itemx --trimblanks
Snip trailing whitespace from the wrapped line when automatic
hard-wrapping occurs or when text is justified.

@item -N
@itemx --noconvert
Disable automatic conversion of files from DOS/Mac format.

@item -O
@itemx --bookstyle
When justifying, treat any line that starts with whitespace as the
beginning of a paragraph (unless auto-indenting is on).

@item -P
@itemx --positionlog
For the 200 most recent files, log the last position of the cursor,
and place it at that position again upon reopening such a file.

@item -Q "@var{regex}"
@itemx --quotestr="@var{regex}"
Set the regular expression for matching the quoting part of a line.
The default value is "@t{^([@w{ }\t]*([!#%:;>|@}]|//))+}".
(Note that @code{\t} stands for a literal Tab character.)
This makes it possible to rejustify blocks of quoted text when composing
email, and to rewrap blocks of line comments when writing source code.

@item -R
@itemx --restricted
Restricted mode: don't read or write to any file not specified on the
command line.  This means: don't read or write history files; don't allow
suspending; don't allow spell checking; don't
allow a file to be appended to, prepended to, or saved under a different
name if it already has one; and don't make backup files.
Restricted mode can also be activated by invoking @command{nano} with
any name beginning with @code{r} (e.g.@: @command{rnano}).

@item -S
@itemx --softwrap
Display over multiple screen rows lines that exceed the screen's width.
(You can make this soft-wrapping occur at whitespace instead of rudely at
the screen's edge, by using also @code{--atblanks}.)
(The old short option, @code{-$}, is deprecated.)

@item -T @var{number}
@itemx --tabsize=@var{number}
Set the displayed tab length to @var{number} columns.  The value of
@var{number} must be greater than 0.  The default value is @t{8}.

@item -U
@itemx --quickblank
Do quick status-bar blanking: status-bar messages will disappear after 1
keystroke instead of 25.  Note that option @option{-c}
(@option{--constantshow}) overrides this.

@item -V
@itemx --version
Show the current version number and exit.

@item -W
@itemx --wordbounds
Detect word boundaries differently by treating punctuation
characters as parts of words.

@item -X "@var{characters}"
@itemx --wordchars="@var{characters}"
Specify which other characters (besides the normal alphanumeric ones)
should be considered as parts of words.  When using this option, you
probably want to omit @option{-W} (@option{--wordbounds}).

@item -Y @var{name}
@itemx --syntax=@var{name}
Specify the syntax to be used for highlighting.
@xref{Syntax Highlighting} for more info.

@item -Z
@itemx --zap
Let an unmodified @key{Backspace} or @key{Delete} erase the marked region
(instead of a single character, and without affecting the cutbuffer).

@item -a
@itemx --atblanks
When doing soft line wrapping, wrap lines at whitespace
instead of always at the edge of the screen.

@item -b
@itemx --breaklonglines
Automatically hard-wrap the current line when it becomes overlong.
(This option is the opposite of @option{-w} (@option{--nowrap}) ---
the last one given takes effect.)

@item -c
@itemx --constantshow
Constantly display the cursor position (line number, column number,
and character number) on the status bar.
Note that this overrides option @option{-U} (@option{--quickblank}).

@item -d
@itemx --rebinddelete
Interpret the Delete and Backspace keys differently so that both Backspace
and Delete work properly.  You should only use this option when on your
system either Backspace acts like Delete or Delete acts like Backspace.

@item -e
@itemx --emptyline
Do not use the line below the title bar, leaving it entirely blank.

@item -f @var{file}
@itemx --rcfile=@var{file}
Read only this @var{file} for setting nano's options, instead of reading
both the system-wide and the user's nanorc files.

@item -g
@itemx --showcursor
Make the cursor visible in the file browser (putting it on the
highlighted item) and in the help viewer.  Useful for braille users
and people with poor vision.

@item -h
@itemx --help
Show a summary of command-line options and exit.

@item -i
@itemx --autoindent
Automatically indent a newly created line to the same number of tabs
and/or spaces as the previous line (or as the next line if the previous
line is the beginning of a paragraph).

@item -j
@itemx --jumpyscrolling
Scroll the buffer contents per half-screen instead of per line.

@item -k
@itemx --cutfromcursor
Make the 'Cut Text' command (normally @kbd{^K}) cut from the current cursor
position to the end of the line, instead of cutting the entire line.

@item -l
@itemx --linenumbers
Display line numbers to the left of the text area.
(Any line with an anchor additionally gets a mark in the margin.)

@item -m
@itemx --mouse
Enable mouse support, if available for your system.  When enabled, mouse
clicks can be used to place the cursor, set the mark (with a double
click), and execute shortcuts.  The mouse will work in the X Window
System, and on the console when gpm is running.  Text can still be
selected through dragging by holding down the Shift key.

@item -n
@itemx --noread
Treat any name given on the command line as a new file.  This allows
@command{nano} to write to named pipes: it will start with a blank buffer,
and will write to the pipe when the user saves the "file".  This way
@command{nano} can be used as an editor in combination with for instance
@command{gpg} without having to write sensitive data to disk first.

@item -o @var{directory}
@itemx --operatingdir=@var{directory}
Set the operating directory.  This makes @command{nano} set up something
similar to a chroot.

@item -p
@itemx --preserve
Preserve the @kbd{^Q} (XON) and @kbd{^S} (XOFF) sequences so data being
sent to the editor can be stopped and started.

@item -q
@itemx --indicator
Display a "scrollbar" on the righthand side of the edit window.
It shows the position of the viewport in the buffer
and how much of the buffer is covered by the viewport.

@item -r @var{number}
@itemx --fill=@var{number}
Set the target width for justifying and automatic hard-wrapping at this
@var{number} of columns.  If the value is 0 or less, wrapping will occur
at the width of the screen minus @var{number} columns, allowing the wrap
point to vary along with the width of the screen if the screen is resized.
The default value is @t{-8}.

@anchor{@option{--speller}}
@item -s "@var{program} [@var{argument} @dots{}]"
@itemx --speller="@var{program} [@var{argument} @dots{}]"
Use the given program to do spell checking and correcting.  By default,
@command{nano} uses the command specified in the @env{SPELL} environment
variable.  If @env{SPELL} is not set, and @option{--speller} is
not specified either, then @command{nano} uses its own interactive spell
corrector, which requires either @command{hunspell} or GNU @command{spell}
to be installed.

@item -t
@itemx --saveonexit
Save a changed buffer without prompting (when exiting with @kbd{^X}).
This can be handy when @command{nano} is used as the composer of an
email program.
(The old form of the long option, @code{--tempfile}, is deprecated.)

@item -u
@item --unix
Save a file by default in Unix format.  This overrides nano's
default behavior of saving a file in the format that it had.
(This option has no effect when you also use @option{--noconvert}.)

@item -v
@itemx --view
Don't allow the contents of the file to be altered: read-only mode.
This mode allows the user to open also other files for viewing,
unless @option{--restricted} is given too.
(Note that this option should NOT be used in place of correct
file permissions to implement a read-only file.)

@item -w
@itemx --nowrap
Do not automatically hard-wrap the current line when it becomes overlong.
This is the default.  (This option is the opposite of @option{-b}
(@option{--breaklonglines}) --- the last one given takes effect.)


@item -x
@itemx --nohelp
Expert Mode: don't show the Shortcut List at the bottom of the screen.
This affects the location of the status bar as well, as in Expert Mode it
is located at the very bottom of the editor.

Note: When accessing the help system, Expert Mode is temporarily
disabled to display the help-system navigation keys.

@item -y
@itemx --afterends
Make Ctrl+Right and Ctrl+Delete stop at word ends instead of beginnings.

@item -z
@itemx --suspendable
Enable the ability to suspend @command{nano} using the system's suspend
keystroke (usually @kbd{^Z}).

@item -%
@itemx --stateflags
Use the top-right corner of the screen for showing some state flags:
@code{I} when auto-indenting, @code{M} when the mark is on, @code{L} when
hard-wrapping (breaking long lines), @code{R} when recording a macro,
and @code{S} when soft-wrapping.
When the buffer is modified, a star (@code{*}) is shown after the
filename in the center of the title bar.

@item -!
@itemx --magic
When neither the file's name nor its first line give a clue,
try using libmagic to determine the applicable syntax.

@end table


@node Editor Basics
@chapter Editor Basics

@menu
* Entering Text::
* Commands::
* The Cutbuffer::
* The Mark::
* Screen Layout::
* Search and Replace::
* Using the Mouse::
* Anchors::
* Limitations::
@end menu

@node Entering Text
@section Entering Text

@command{nano} is a "modeless" editor.  This means that all keystrokes,
with the exception of Control and Meta sequences, enter text into the
file being edited.

Characters not present on the keyboard can be entered in two ways:

@itemize @bullet
@item
For characters with a single-byte code,
pressing the Esc key twice and then typing a three-digit decimal number
(from @kbd{000} to @kbd{255}) will make @command{nano} behave as if you
typed the key with that value.

@item
For any possible character, pressing @kbd{M-V} (Alt+V) and then typing a
six-digit hexadecimal number (starting with @kbd{0} or @kbd{1}) will enter the
corresponding Unicode character into the buffer.
@end itemize

For example, typing @kbd{Esc Esc 2 3 4} will enter the character "ê" ---
useful when writing about a French party.  Typing @kbd{M-V 0 0 2 2 c 4}
will enter the symbol "⋄", a little diamond.

@node Commands
@section Commands

Commands are given by using the Control key (Ctrl, shown as @kbd{^})
or the Meta key (Alt or Cmd, shown as @kbd{M-}).

@itemize @bullet
@item
A control-key sequence is entered by holding down the Ctrl key and
pressing the desired key.

@item
A meta-key sequence is entered by holding down the Meta key (normally
the Alt key) and pressing the desired key.
@end itemize

If for some reason on your system the combinations with Ctrl or Alt do
not work, you can generate them by using the Esc key.  A control-key
sequence is generated by pressing the Esc key twice and then pressing
the desired key, and a meta-key sequence by pressing the Esc key once
and then pressing the desired key.

@node The Cutbuffer
@section The Cutbuffer

Text can be cut from a file a whole line at a time with @kbd{^K}.
The cut line is stored in the cutbuffer.  Consecutive strokes of @kbd{^K}
will add each cut line to this buffer, but a @kbd{^K}
after any other keystroke will overwrite the entire cutbuffer.

The contents of the cutbuffer can be pasted at the current cursor position
with @kbd{^U}.

A line of text can be copied into the cutbuffer (without cutting it)
with @kbd{M-6}.

@node The Mark
@section The Mark

Text can be selected by first 'setting the Mark' with @kbd{^6}
or @kbd{M-A} and then moving the cursor to the other end of the portion
to be selected.  The selected portion of text will be highlighted.
This selection can now be cut or copied in its entirety with a single
@kbd{^K} or @kbd{M-6}.  Or the selection can be used to limit the scope of
a search-and-replace (@kbd{^\}) or spell-checking session (@kbd{^T}).

On some terminals, text can be selected also by holding down @kbd{Shift}
while using the cursor keys.  Holding down the @kbd{Ctrl} or @kbd{Alt}
key too will increase the stride.  Such a selection is cancelled
upon any cursor movement where @kbd{Shift} isn't held.

Cutting or copying selected text toggles off the mark automatically.
If needed, it can be toggled off manually with another @kbd{^6} or @kbd{M-A}.

@node Screen Layout
@section Screen Layout

The default screen of nano consists of five areas.  From top to bottom
these are: the title bar, a blank line, the edit window, the status bar,
and two help lines.

The title bar consists of
three sections: left, center and right.  The section on the left
displays the version of @command{nano} being used.  The center section
displays the current filename, or "New Buffer" if the file has not yet
been named.  The section on the right displays "Modified" if the
file has been modified since it was last saved or opened.

The status bar is the third line from the bottom of the screen.  It
shows important and informational messages.  Any error messages that
occur from using the editor will appear on the status bar.  Any questions
that are asked of the user will be asked on the status bar, and any user
input (search strings, filenames, etc.) will be input on the status bar.

The two help lines at the bottom of the screen show some of the most
essential functions of the editor.  These two lines are called the
Shortcut List.

@node Search and Replace
@section Search and Replace

One can search the current buffer for the occurrence of any string
with the Search command (default key binding: @kbd{^W}).  The default search
mode is forward, case-insensitive, and for literal strings.  But one
can search backwards by pressing @kbd{M-B}, search case sensitively with @kbd{M-C},
and interpret regular expressions in the search string with @kbd{M-R}.

A regular expression in a search string always covers just one line;
it cannot span multiple lines.  And when replacing (with @kbd{^\} or @kbd{M-R})
the replacement string cannot contain a newline (LF).

@node Using the Mouse
@section Using the Mouse

When mouse support has been configured and enabled, a single mouse click
places the cursor at the indicated position.  Clicking a second time in
the same position toggles the mark.  Clicking in the shortcut list
executes the selected shortcut.  To be able to select text with the
left button, or paste text with the middle button, hold down the
Shift key during those actions.

The mouse will work in the X Window System, and on the console when gpm
is running.

@node Anchors
@section Anchors

With @kbd{M-Ins} you can place an anchor (a kind of temporary bookmark)
at the current line.  With @kbd{M-PgUp} and @kbd{M-PgDn} you can jump
to an anchor in the backward/forward direction.  This jumping wraps
around at the top and bottom.

When a line with an anchor is removed, the line where the cursor ends up
inherits the anchor.  After performing an operation on the entire buffer
(like formatting it, piping it through a command, or doing an external
spell check on it), any anchors that were present are gone.  And when
you close the buffer, all its anchors simply disappear; they are not saved.

Anchors are visualized in the margin when line numbers are activated.

@node Limitations
@section Limitations

The recording and playback of keyboard macros works correctly only on a
terminal emulator, not on a Linux console (VT), because the latter does
not by default distinguish modified from unmodified arrow keys.


@node Built-in Help
@chapter Built-in Help

The built-in help system in @command{nano} is available by pressing @kbd{^G}.
It is fairly self-explanatory.  It documents the various parts of the
editor and the available keystrokes.  Navigation is via the @kbd{^Y} (Page Up)
and @kbd{^V} (Page Down) keys.  @kbd{^X} exits from the help system.


@node The File Browser
@chapter The File Browser

When in the Read-File (@kbd{^R}) or Write-Out menu (@kbd{^O}),
pressing @kbd{^T} will invoke the file browser.
Here, one can navigate directories in a graphical manner in order to
find the desired file.

Basic movement in the file browser is accomplished with the arrow and
other cursor-movement keys.  More targeted movement is accomplished by
searching, via @kbd{^W} or @kbd{w}, or by changing directory, via
@kbd{^_} or @kbd{g}.  The behavior of the @kbd{Enter} key (or @kbd{s})
varies by what is currently selected.
If the currently selected object is a directory, the file browser will
enter and display the contents of the directory.  If the object is a
file, this filename and path are copied to the status bar, and the file
browser exits.


@node Feature Toggles
@chapter Feature Toggles

Toggles allow you to change on-the-fly certain aspects of the editor
which would normally be specified via command-line options.  They are
invoked via Meta-key sequences (@pxref{Commands} for more info).
The following global toggles are available:

@table @code

@item Constant Cursor Position Display
@kbd{Meta-C} toggles the @option{-c} (@option{--constantshow}) command-line option.

@item Smart Home Key
@kbd{Meta-H} toggles the @option{-A} (@option{--smarthome}) command-line option.

@item Auto Indent
@kbd{Meta-I} toggles the @option{-i} (@option{--autoindent}) command-line option.

@item Cut From Cursor To End-of-Line
@kbd{Meta-K} toggles the @option{-k} (@option{--cutfromcursor}) command-line option.

@item Long-Line Wrapping
@kbd{Meta-L} toggles the @option{-b} (@option{--breaklonglines}) command-line option.

@item Mouse Support
@kbd{Meta-M} toggles the @option{-m} (@option{--mouse}) command-line option.

@item Line Numbers
@kbd{Meta-N} toggles the @option{-l} (@option{--linenumbers}) command-line option.

@item Tabs To Spaces
@kbd{Meta-O} toggles the @option{-E} (@option{--tabstospaces}) command-line option.

@item Whitespace Display
@kbd{Meta-P} toggles the displaying of whitespace (@pxref{Whitespace}).

@item Soft Wrapping
@kbd{Meta-S} toggles the @option{-S} (@option{--softwrap}) command-line option.

@item Expert/No Help
@kbd{Meta-X} toggles the @option{-x} (@option{--nohelp}) command-line option.

@item Color Syntax Highlighting
@kbd{Meta-Y} toggles color syntax highlighting (if your nanorc defines syntaxes
--- @pxref{Syntax Highlighting}).

@item Suspension
@kbd{Meta-Z} toggles the @option{-z} (@option{--suspendable}) command-line option.

@end table


@node Nanorc Files
@chapter Nanorc Files

The nanorc files contain the default settings for @command{nano}.  During
startup, if @option{--rcfile} is not given, @command{nano} will read two files:
first the system-wide settings, from @file{/etc/nanorc} (the exact path
might be different on your system), and then the user-specific settings,
either from @file{~/.nanorc} or from @file{$XDG_CONFIG_HOME/nano/nanorc}
or from @file{.config/nano/nanorc}, whichever exists first.
If @option{--rcfile} is given, @command{nano} will read just the
specified settings file.

A nanorc file accepts a series of "set" and "unset" commands, which can
be used to configure @command{nano} on startup without using command-line
options.  Additionally, there are some commands to define syntax highlighting
and to rebind keys --- @pxref{Syntax Highlighting} and @ref{Rebinding Keys}.
@command{nano} will read one command per line.
All commands and keywords should be written in lowercase.

Options in nanorc files take precedence over @command{nano}'s defaults, and
command-line options override nanorc settings.  Also, options that do not
take an argument are unset by default.  So using the @code{unset} command
is only needed when wanting to override a setting of the system's nanorc
file in your own nanorc.  Options that take an argument cannot be unset.

Quotes inside the @var{characters} parameters below should not be escaped.
The last double quote on the line will be seen as the closing quote.

@menu
* Settings::
* Syntax Highlighting::
* Rebinding Keys::
@end menu

@node Settings
@section Settings

The supported settings in a nanorc file are:

@table @code

@item set afterends
Make Ctrl+Right and Ctrl+Delete stop at word ends instead of beginnings.

@item set allow_insecure_backup
When backing up files, allow the backup to succeed even if its
permissions can't be (re)set due to special OS considerations.
You should NOT enable this option unless you are sure you need it.

@item set atblanks
When soft line wrapping is enabled, make it wrap lines at blank characters
(tabs and spaces) instead of always at the edge of the screen.

@item set autoindent
Automatically indent a newly created line to the same number of tabs
and/or spaces as the previous line (or as the next line if the previous
line is the beginning of a paragraph).

@item set backup
When saving a file, back up the previous version of it, using the current
filename suffixed with a tilde (@code{~}).

@item set backupdir "@var{directory}"
Make and keep not just one backup file, but make and keep a uniquely
numbered one every time a file is saved --- when backups are enabled
with @code{set backup} or @option{--backup} or @option{-B}.
The uniquely numbered files are stored in the specified directory.

@item set boldtext
Use bold instead of reverse video for the title bar, status bar, key combos,
function tags, line numbers, and selected text.  This is overridden by
setting the options @code{titlecolor}, @code{statuscolor}, @code{keycolor},
@code{functioncolor}, @code{numbercolor}, and/or @code{selectedcolor}.

@item set bookstyle
When justifying, treat any line that starts with whitespace as the
beginning of a paragraph (unless auto-indenting is on).

@item set brackets "@var{characters}"
Set the characters treated as closing brackets when justifying
paragraphs.  This may not include blank characters.  Only closing
punctuation (see @code{set punct}), optionally followed by the specified
closing brackets, can end sentences.  The default value is
"@t{"')>]@}}".

@item set breaklonglines
Automatically hard-wrap the current line when it becomes overlong.

@item set casesensitive
Do case-sensitive searches by default.

@item set constantshow
Constantly display the cursor position on the status bar.
Note that this overrides @option{quickblank}.

@item set cutfromcursor
Use cut-from-cursor-to-end-of-line by default, instead of cutting the whole line.

@item set emptyline
Do not use the line below the title bar, leaving it entirely blank.

@item set errorcolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the status bar when an error message is displayed.
The default value is @t{brightwhite,red}.
@xref{@code{set functioncolor}} for valid color names.

@item set fill @var{number}
Set the target width for justifying and automatic hard-wrapping at this
@var{number} of columns.  If the value is 0 or less, wrapping will occur
at the width of the screen minus @var{number} columns, allowing the wrap
point to vary along with the width of the screen if the screen is resized.
The default value is @t{-8}.

@anchor{@code{set functioncolor}}
@item set functioncolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the concise function descriptions
in the two help lines at the bottom of the screen.
Valid names for the foreground and background colors are:
@code{red}, @code{green}, @code{blue},
@code{magenta}, @code{yellow}, @code{cyan},
@code{white}, and @code{black}.
Each of these eight names may be prefixed with the word
@code{light} to get a brighter version of that color.

On terminal emulators that can do at least 256 colors,
other valid (but unprefixable) color names are:
@code{pink}, @code{purple}, @code{mauve},
@code{lagoon}, @code{mint}, @code{lime},
@code{peach}, @code{orange}, @code{latte}, and @code{normal}
--- where @code{normal} means the default foreground or background color.
Either @var{fgcolor} or ,@var{bgcolor} may be left out,
and the pair may be preceded by @code{bold} and/or @code{italic}
(separated by commas) to get a bold and/or slanting typeface,
if your terminal can do those.

@item set guidestripe @var{number}
Draw a vertical stripe at the given column, to help judge the width of the
text.  (The color of the stripe can be changed with @code{set stripecolor}.)

@item set historylog
Save the last hundred search strings and replacement strings and
executed commands, so they can be easily reused in later sessions.

@item set jumpyscrolling
Scroll the buffer contents per half-screen instead of per line.

@item set keycolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the shortcut key combos
in the two help lines at the bottom of the screen.
@xref{@code{set functioncolor}} for valid color names.

@item set linenumbers
Display line numbers to the left of the text area.
(Any line with an anchor additionally gets a mark in the margin.)

@item set locking
Enable vim-style lock-files for when editing files.

@item set magic
When neither the file's name nor its first line give a clue,
try using libmagic to determine the applicable syntax.
(Calling libmagic can be relatively time consuming.
It is therefore not done by default.)

@anchor{@code{set matchbrackets}}
@item set matchbrackets "@var{characters}"
Specify the opening and closing brackets that can be found by bracket
searches.  This may not include blank characters.  The opening set must
come before the closing set, and the two sets must be in the same order.
The default value is "@t{(<[@{)>]@}}".

@item set morespace
Deprecated option since it has become the default setting.
When needed, use @code{unset emptyline} instead.

@item set mouse
Enable mouse support, so that mouse clicks can be used to place the
cursor, set the mark (with a double click), or execute shortcuts.

@item set multibuffer
When reading in a file with @kbd{^R}, insert it into a new buffer by default.

@item set noconvert
Don't convert files from DOS/Mac format.

@item set nohelp
Don't display the help lists at the bottom of the screen.

@item set nonewlines
Don't automatically add a newline when a text does not end with one.
(This can cause you to save non-POSIX text files.)

@item set nopauses
Obsolete option.  Ignored.

@item set nowrap
Deprecated option since it has become the default setting.
When needed, use @code{unset breaklonglines} instead.

@item set numbercolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for line numbers.
@xref{@code{set functioncolor}} for valid color names.

@item set operatingdir "@var{directory}"
@command{nano} will only read and write files inside "directory" and its
subdirectories.  Also, the current directory is changed to here, so
files are inserted from this directory.  By default, the operating
directory feature is turned off.

@item set positionlog
Save the cursor position of files between editing sessions.
The cursor position is remembered for the 200 most-recently edited files.

@item set preserve
Preserve the XON and XOFF keys (@kbd{^Q} and @kbd{^S}).

@item set indicator
Display a "scrollbar" on the righthand side of the edit window.
It shows the position of the viewport in the buffer
and how much of the buffer is covered by the viewport.

@item set promptcolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the prompt bar.
When this option is not specified, the colors of the title bar are used.
@xref{@code{set functioncolor}} for valid color names.

@item set punct "@var{characters}"
Set the characters treated as closing punctuation when justifying
paragraphs.  This may not include blank characters.  Only the
specified closing punctuation, optionally followed by closing brackets
(see @code{set brackets}), can end sentences.
The default value is "@t{!.?}".

@item set quickblank
Do quick status-bar blanking: status-bar messages will disappear after 1
keystroke instead of 25.  Note that @option{constantshow} overrides this.

@item set quotestr "@var{regex}"
Set the regular expression for matching the quoting part of a line.
The default value is "@t{^([@w{ }\t]*([!#%:;>|@}]|//))+}".
(Note that @code{\t} stands for a literal Tab character.)
This makes it possible to rejustify blocks of quoted text when composing
email, and to rewrap blocks of line comments when writing source code.

@item set rawsequences
Interpret escape sequences directly (instead of asking @code{ncurses} to
translate them).  If you need this option to get your keyboard to work
properly, please report a bug.  Using this option disables @command{nano}'s
mouse support.

@item set rebinddelete
Interpret the Delete and Backspace keys differently so that both Backspace
and Delete work properly.  You should only use this option when on your
system either Backspace acts like Delete or Delete acts like Backspace.

@item set regexp
Do regular-expression searches by default.
Regular expressions in @command{nano} are of the extended type (ERE).

@item set saveonexit
Save a changed buffer automatically on exit (@kbd{^X}); don't prompt.
(The old form of this option, @code{set tempfile}, is deprecated.)

@item set scrollercolor @var{fgcolor},@var{bgcolor}
Use this color combination for the indicator alias "scrollbar".
(On terminal emulators that link to a libvte older than version 0.55,
using a background color here does not work correctly.)
@xref{@code{set functioncolor}} for valid color names.

@item set selectedcolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for selected text.
@xref{@code{set functioncolor}} for valid color names.

@item set showcursor
Put the cursor on the highlighted item in the file browser, and show
the cursor in the help viewer, to aid braille users and people with
poor vision.

@item set smarthome
Make the Home key smarter.  When Home is pressed anywhere but at the
very beginning of non-whitespace characters on a line, the cursor will
jump to that beginning (either forwards or backwards).  If the cursor is
already at that position, it will jump to the true beginning of the
line.

@item set smooth
Deprecated option since it has become the default setting.
When needed, use @code{unset jumpyscrolling} instead.

@item set softwrap
Display lines that exceed the screen's width over multiple screen lines.
(You can make this soft-wrapping occur at whitespace instead of rudely at
the screen's edge, by using also @code{set atblanks}.)

@item set speller "@var{program} [@var{argument} @dots{}]"
Use the given program to do spell checking and correcting.
@xref{@option{--speller}} for details.

@item set stateflags
Use the top-right corner of the screen for showing some state flags:
@code{I} when auto-indenting, @code{M} when the mark is on, @code{L} when
hard-wrapping (breaking long lines), @code{R} when recording a macro,
and @code{S} when soft-wrapping.
When the buffer is modified, a star (@code{*}) is shown after the
filename in the center of the title bar.

@item set statuscolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the status bar.
@xref{@code{set functioncolor}} for valid color names.

@item set stripecolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the vertical guiding stripe.
@xref{@code{set functioncolor}} for valid color names.

@item set suspendable
Allow @command{nano} to be suspended (with @kbd{^Z} by default).

@item set tabsize @var{number}
Use a tab size of @var{number} columns.  The value of @var{number} must be
greater than 0.  The default value is @t{8}.

@item set tabstospaces
Convert typed tabs to spaces.

@item set titlecolor [bold,][italic,]@var{fgcolor},@var{bgcolor}
Use this color combination for the title bar.
@xref{@code{set functioncolor}} for valid color names.

@item set trimblanks
Remove trailing whitespace from wrapped lines when automatic
hard-wrapping occurs or when text is justified.

@item set unix
Save a file by default in Unix format.  This overrides nano's
default behavior of saving a file in the format that it had.
(This option has no effect when you also use @code{set noconvert}.)

@anchor{Whitespace}
@item set whitespace "@var{characters}"
Set the two characters used to indicate the presence of tabs and
spaces.  They must be single-column characters.  The default pair
for a UTF-8 locale is @t{"»·"}, and for other locales @t{">."}.

@item set wordbounds
Detect word boundaries differently by treating punctuation
characters as part of a word.

@item set wordchars "@var{characters}"
Specify which other characters (besides the normal alphanumeric ones)
should be considered as parts of words.  When using this option, you
probably want to unset @code{wordbounds}.

@item set zap
Let an unmodified @key{Backspace} or @key{Delete} erase the marked region
(instead of a single character, and without affecting the cutbuffer).

@end table

@node Syntax Highlighting
@section Syntax Highlighting

Coloring the different syntactic elements of a file
is done via regular expressions (see the @code{color} command below).
This is inherently imperfect, because regular expressions are not
powerful enough to fully parse a file.  Nevertheless, regular
expressions can do a lot and are easy to make, so they are a
good fit for a small editor like @command{nano}.

See @file{/usr/share/nano/} and @file{/usr/share/nano/extra/}
for the syntax-coloring definitions that are available out of the box.

All regular expressions in @command{nano} are POSIX extended regular expressions
(ERE).  This means that @code{.}, @code{?}, @code{*}, @code{+}, @code{^},
@code{$}, and several other characters are special.
The period @code{.} matches any single character,
@code{?} means the preceding item is optional,
@code{*} means the preceding item may be matched zero or more times,
@code{+} means the preceding item must be matched one or more times,
@code{^} matches the beginning of a line, and @code{$} the end,
@code{\<} matches the start of a word, and @code{\>} the end,
and @code{\s} matches a blank.
It also means that lookahead and lookbehind are not possible.
A complete explanation can be found in the manual of GNU grep:
@code{info grep regular}.

A separate syntax can be defined for each kind of file
via the following commands in a nanorc file:

@table @code

@item syntax @var{name} ["@var{fileregex}" @dots{}]
Start the definition of a syntax with this @var{name}.
All subsequent @code{color} and other such commands
will be added to this syntax, until a new @code{syntax}
command is encountered.

When @command{nano} is run, this syntax will be automatically
activated if the current filename matches the extended regular
expression @var{fileregex}.  Or the syntax can be explicitly
activated by using the @option{-Y} or @option{--syntax}
command-line option followed by the @var{name}.

The @code{default} syntax is special: it takes no @var{fileregex},
and applies to files that don't match any syntax's regexes.
The @code{none} syntax is reserved; specifying it on the
command line is the same as not having a syntax at all.

@item header "@var{regex}" @dots{}
If from all defined syntaxes no @var{fileregex} matched, then compare
this @var{regex} (or regexes) against the first line of the current file,
to determine whether this syntax should be used for it.

@item magic "@var{regex}" @dots{}
If no @var{fileregex} matched and no @code{header} regex matched
either, then compare this @var{regex} (or regexes) against the
result of querying the @code{magic} database about the current
file, to determine whether this syntax should be used for it.
(This functionality only works when @code{libmagic} is installed
on the system and will be silently ignored otherwise.)

@item formatter @var{program} [@var{argument} @dots{}]
Run the given @var{program} on the full contents of the current buffer.
(The current buffer is written out to a temporary file, the program is
run on it, and then the temporary file is read back in, replacing the
contents of the buffer.)

@item linter @var{program} [@var{argument} @dots{}]
Use the given @var{program} to do a syntax check on the current buffer.

@item comment "@var{string}"
Use the given string for commenting and uncommenting lines.
If the string contains a vertical bar or pipe character (@t{|}),
this designates bracket-style comments; for example, @t{"/*|*/"} for
CSS files.  The characters before the pipe are prepended to the line and the
characters after the pipe are appended at the end of the line.  If no pipe
character is present, the full string is prepended; for example, @t{"#"} for
Python files.  If empty double quotes are specified, the comment/uncomment
functions are disabled; for example, @t{""} for JSON.
The default value is "@t{#}".

@item tabgives "@var{string}"
Make the <Tab> key produce the given @var{string}.  Useful for languages like
Python that want to see only spaces for indentation.
This overrides the setting of the @code{tabstospaces} option.

@item color [bold,][italic,]@var{fgcolor},@var{bgcolor} "@var{regex}" @dots{}
Paint all pieces of text that match the extended regular expression "regex"
with the given foreground and background colors, at least one of which must
be specified.  Valid color names are:
@code{red}, @code{green}, @code{blue},
@code{magenta}, @code{yellow}, @code{cyan},
@code{white}, and @code{black}.
Each of these eight names may be prefixed with the word
@code{light} to get a brighter version of that color.

On terminal emulators that can do at least 256 colors,
other valid (but unprefixable) color names are:
@code{pink}, @code{purple}, @code{mauve},
@code{lagoon}, @code{mint}, @code{lime},
@code{peach}, @code{orange}, @code{latte}, and @code{normal}
--- where @code{normal} means the default foreground or background color.
The color pair may be preceded by @code{bold} and/or @code{italic}
(separated by commas) to get a bold and/or slanting typeface,
if your terminal can do those.

All coloring commands are applied in the order in which they are specified,
which means that later commands can recolor stuff that was colored earlier.

@item icolor [bold,][italic,]@var{fgcolor},@var{bgcolor} "@var{regex}" @dots{}
Same as above, except that the matching is case insensitive.

@item color [bold,][italic,]@var{fgcolor},@var{bgcolor} start="@var{fromrx}" end="@var{torx}"
Paint all pieces of text whose start matches extended regular expression
"fromrx" and whose end matches extended regular expression "torx" with
the given foreground and background colors, at least one of
which must be specified.  This means that, after an initial instance of
"fromrx", all text until the first instance of "torx" will be colored.
This allows syntax highlighting to span multiple lines.

@item icolor [bold,][italic,]@var{fgcolor},@var{bgcolor} start="@var{fromrx}" end="@var{torx}"
Same as above, except that the matching is case insensitive.

@item include "@var{syntaxfile}"
Read in self-contained color syntaxes from "syntaxfile".  Note that
"syntaxfile" may contain only the above commands, from @code{syntax}
to @code{icolor}.

@item extendsyntax @var{name} @var{command} @var{argument} @dots{}
Extend the syntax previously defined as "@var{name}" with another @var{command}.
This allows you to add a new @code{color}, @code{icolor}, @code{header},
@code{magic}, @code{formatter}, @code{linter}, @code{comment},
or @code{tabgives} command to an already
defined syntax --- useful when you want to slightly improve a syntax defined
in one of the system-installed files (which normally are not writable).

@end table

@node Rebinding Keys
@section Rebinding Keys

Key bindings can be changed via the following three commands in a
nanorc file:

@table @code

@item bind key function menu
Rebinds @code{key} to @code{function} in the context of @code{menu}
(or in all menus where the function exists when @code{all} is used).

@item bind key "string" menu
Makes @code{key} produce @code{string} in the context of @code{menu}
(or in all menus where the key exists when @code{all} is used).
The @code{string} can consist of text or commands or a mix of them.
(To enter a command into the @code{string}, precede its keystroke
with @kbd{M-V}.)

@item unbind key menu
Unbinds @code{key} from @code{menu}
(or from all menus where the key exists when @code{all} is used).

@end table

@sp 1
The format of @code{key} should be one of:

@itemize @w{}
@item
@code{^@var{X}} ------ where @var{X} is a Latin letter, or one of several
ASCII characters (@@, ], \, ^, _), or the word "Space".
Example: @code{^C}.

@item
@code{M-@var{X}} ------ where @var{X} is any ASCII character except [,
or the word "Space".
Example: @code{M-8}.

@item
@code{Sh-M-@var{X}} ------ where @var{X} is a Latin letter.
Example: @code{Sh-M-U}.
By default, each Meta+letter keystroke does the same as the corresponding
Shift+Meta+letter.  But when any Shift+Meta bind is made, that will
no longer be the case, for all letters.

@item
@code{F@var{n}} ------ where @var{n} is a numeric value from 1 to 24.
Example: @code{F10}.
(Often, @code{F13} to @code{F24} can be typed as @code{F1} to @code{F12}
with Shift.)

@item
@code{Ins} or @code{Del}.
@end itemize

Rebinding @code{^M} (Enter) or @code{^I} (Tab) is probably not a good idea.
Rebinding @code{^[} (Esc) is not possible, because its keycode
is the starter byte of Meta keystrokes and escape sequences.
Rebinding any of the dedicated cursor-moving keys (the arrows, Home, End,
PageUp and PageDown) is not possible.
On some terminals it's not possible to rebind @code{^H} (unless @code{--raw}
is used) because its keycode is identical to that of the Backspace key.

@sp 1
Valid names for the @code{function} to be bound are:

@table @code

@item help
Invokes the help viewer.

@item cancel
Cancels the current command.

@item exit
Exits from the program (or from the help viewer or file browser).

@item writeout
Writes the current buffer to disk, asking for a name.

@item savefile
Writes the current file to disk without prompting.

@item insert
Inserts a file into the current buffer (at the current cursor position),
or into a new buffer when option @code{multibuffer} is set.

@item whereis
Starts a forward search for text in the current buffer --- or for filenames
matching a string in the current list in the file browser.

@item wherewas
Starts a backward search for text in the current buffer --- or for filenames
matching a string in the current list in the file browser.

@item findprevious
Searches the next occurrence in the backward direction.

@item findnext
Searches the next occurrence in the forward direction.

@item replace
Interactively replaces text within the current buffer.

@item cut
Cuts and stores the current line (or the marked region).

@item copy
Copies the current line (or the marked region) without deleting it.

@item paste
Pastes the currently stored text into the current buffer at the
current cursor position.

@item zap
Throws away the current line (or the marked region).
(This function is bound by default to <Meta+Delete>.)

@item chopwordleft
Deletes from the cursor position to the beginning of the preceding word.
(This function is bound by default to <Shift+Ctrl+Delete>.  If your terminal
produces @code{^H} for <Ctrl+Backspace>, you can make <Ctrl+Backspace> delete
the word to the left of the cursor by rebinding @kbd{^H} to this function.)

@item chopwordright
Deletes from the cursor position to the beginning of the next word.
(This function is bound by default to <Ctrl+Delete>.)

@item cutrestoffile
Cuts all text from the cursor position till the end of the buffer.

@item mark
Sets the mark at the current position, to start selecting text.
Or, when it is set, unsets the mark.

@item location
Reports the current position of the cursor in the buffer:
the line, column, and character positions.
(The old name of this function, 'curpos', is deprecated.)

@item wordcount
Counts the number of words, lines and characters in the current buffer.

@item execute
Prompts for a program to execute.  The program's output will be inserted
into the current buffer (or into a new buffer when @kbd{M-F} is toggled).

@item speller
Invokes a spell-checking program, either the default @command{hunspell}
or GNU @command{spell}, or the one defined by @option{--speller} or
@code{set speller}.

@item formatter
Invokes a full-buffer-processing program (if the active syntax defines one).

@item linter
Invokes a syntax-checking program (if the active syntax defines one).

@item justify
Justifies the current paragraph.  A paragraph is a group of contiguous lines
that, apart from possibly the first line, all have the same indentation.  The
beginning of a paragraph is detected by either this lone line with a differing
indentation or by a preceding blank line.

@item fulljustify
Justifies the entire current buffer.

@item indent
Indents (shifts to the right) the currently marked text.

@item unindent
Unindents (shifts to the left) the currently marked text.

@item comment
Comments or uncomments the current line or marked lines, using the comment
style specified in the active syntax.

@item complete
Completes the fragment before the cursor to a full word found elsewhere
in the current buffer.

@item left
Goes left one position (in the editor or browser).

@item right
Goes right one position (in the editor or browser).

@item up
Goes one line up (in the editor or browser).

@item down
Goes one line down (in the editor or browser).

@item scrollup
Scrolls the viewport up one row (meaning that the text slides down)
while keeping the cursor in the same text position, if possible.

@item scrolldown
Scrolls the viewport down one row (meaning that the text slides up)
while keeping the cursor in the same text position, if possible.

@item center
Scrolls the line with the cursor to the middle of the screen.

@item prevword
Moves the cursor to the beginning of the previous word.

@item nextword
Moves the cursor to the beginning of the next word.

@item home
Moves the cursor to the beginning of the current line.

@item end
Moves the cursor to the end of the current line.

@item beginpara
Moves the cursor to the beginning of the current paragraph.

@item endpara
Moves the cursor to the end of the current paragraph.

@item prevblock
Moves the cursor to the beginning of the current or preceding block of text.
(Blocks are separated by one or more blank lines.)

@item nextblock
Moves the cursor to the beginning of the next block of text.

@item pageup
Goes up one screenful.

@item pagedown
Goes down one screenful.

@item firstline
Goes to the first line of the file.

@item lastline
Goes to the last line of the file.

@item gotoline
Goes to a specific line (and column if specified).  Negative numbers count
from the end of the file (and end of the line).

@item findbracket
Moves the cursor to the bracket (or brace or parenthesis, etc.) that matches
(pairs) with the one under the cursor.  @xref{@code{set matchbrackets}}.

@item anchor
Places an anchor at the current line, or removes it when already present.
(An anchor is visible when line numbers are activated.)

@item prevanchor
Goes to the first anchor before the current line.

@item nextanchor
Goes to the first anchor after the current line.

@item prevbuf
Switches to editing/viewing the previous buffer when multiple buffers are open.

@item nextbuf
Switches to editing/viewing the next buffer when multiple buffers are open.

@item verbatim
Inserts the next keystroke verbatim into the file.

@item tab
Inserts a tab at the current cursor location.

@item enter
Inserts a new line below the current one.

@item delete
Deletes the character under the cursor.

@item backspace
Deletes the character before the cursor.

@item recordmacro
Starts the recording of keystrokes --- the keystrokes are stored
as a macro.  When already recording, the recording is stopped.

@item runmacro
Replays the keystrokes of the last recorded macro.

@item undo
Undoes the last performed text action (add text, delete text, etc).

@item redo
Redoes the last undone action (i.e., it undoes an undo).

@item refresh
Refreshes the screen.

@item suspend
Suspends the editor (if the suspending function is enabled, see the
@code{suspendable} toggle item below).

@item casesens
Toggles whether searching/replacing ignores or respects the case of
the given characters.

@item regexp
Toggles whether searching/replacing uses literal strings or regular expressions.

@item backwards
Toggles whether searching/replacing goes forward or backward.

@item older
Retrieves the previous (earlier) entry at a prompt.

@item newer
Retrieves the next (later) entry at a prompt.

@item flipreplace
Toggles between searching for something and replacing something.

@item flipgoto
Toggles between searching for text and targeting a line number.

@item flipexecute
Toggles between inserting a file and executing a command.

@item flippipe
When executing a command, toggles whether the current buffer (or marked
region) is piped to the command.

@item flipnewbuffer
Toggles between inserting into the current buffer and into a new
empty buffer.

@item flipconvert
When reading in a file, toggles between converting and not converting
it from DOS/Mac format.  Converting is the default.

@item dosformat
When writing a file, switches to writing a DOS format (CR/LF).

@item macformat
When writing a file, switches to writing a Mac format.

@item append
When writing a file, appends to the end instead of overwriting.

@item prepend
When writing a file, 'prepends' (writes at the beginning) instead of overwriting.

@item backup
When writing a file, creates a backup of the current file.

@item discardbuffer
When about to write a file, discard the current buffer without saving.
(This function is bound by default only when option @option{--saveonexit}
is in effect.)

@item browser
Starts the file browser (in the Read File and Write Out menus),
allowing to select a file from a list.

@item gotodir
Goes to a directory to be specified, allowing to browse anywhere
in the filesystem.

@item firstfile
Goes to the first file in the list when using the file browser.

@item lastfile
Goes to the last file in the list when using the file browser.

@item nohelp
Toggles the presence of the two-line list of key bindings at the bottom of the screen.
(This toggle is special: it is available in all menus except the help viewer
and the linter.  All further toggles are available in the main menu only.)

@item constantshow
Toggles the constant display of the current line, column, and character positions.

@item softwrap
Toggles the displaying of overlong lines on multiple screen lines.

@item linenumbers
Toggles the display of line numbers in front of the text.

@item whitespacedisplay
Toggles the showing of whitespace.

@item nosyntax
Toggles syntax highlighting.

@item smarthome
Toggles the smartness of the Home key.

@item autoindent
Toggles whether a newly created line will contain the same amount of leading
whitespace as the preceding line --- or as the next line if the preceding line
is the beginning of a paragraph.

@item cutfromcursor
Toggles whether cutting text will cut the whole line or just from the current cursor
position to the end of the line.

@item nowrap
Toggles whether long lines will be hard-wrapped to the next line.

@item tabstospaces
Toggles whether typed tabs will be converted to spaces.

@item mouse
Toggles mouse support.

@item suspendable
Toggles whether the suspend keystroke (@kbd{^Z} by default)
will actually suspend the editor.
(The old name of this function, 'suspendenable', is deprecated.)

@end table

@sp 1
Valid names for @code{menu} are:

@table @code

@item main
The main editor window where text is entered and edited.

@item help
The help-viewer menu.

@item search
The search menu (AKA whereis).

@item replace
The 'search to replace' menu.

@item replacewith
The 'replace with' menu, which comes up after 'search to replace'.

@item yesno
The 'yesno' menu, where the Yes/No/All/Cancel question is asked.

@item gotoline
The 'goto line (and column)' menu.

@item writeout
The 'write file' menu.

@item insert
The 'insert file' menu.

@item browser
The 'file browser' menu, for selecting a file to be opened or
inserted or written to.

@item whereisfile
The 'search for a file' menu in the file browser.

@item gotodir
The 'go to directory' menu in the file browser.

@item execute
The menu for inserting the output from an external command,
or for filtering the buffer (or the marked region) through
an external command, or for executing one of several tools.
(The old form of this menu name, 'extcmd', is deprecated.)

@item spell
The menu of the integrated spell checker where the user can edit a misspelled word.

@item linter
The linter menu, which allows jumping through the linting messages.

@item all
A special name that encompasses all menus.  For @code{bind} it means
all menus where the specified @code{function} exists; for @code{unbind}
it means all menus where the specified @code{key} exists.

@end table


@node Pico Compatibility
@chapter Pico Compatibility

@command{nano} emulates Pico quite closely, but there
are some differences between the two editors:

@table @code

@item Hard-Wrapping
Unlike Pico, @command{nano} does not automatically hard-wrap the current
line when it becomes overlong during typing.  This hard-wrapping can be
switched on with the @option{--breaklonglines} option.  With that option,
@command{nano} by default breaks lines at screen width minus eight columns,
whereas Pico does it at screen width minus six columns. You can make
@command{nano} do as Pico by using @option{--fill=-6}.

@item Scrolling
By default, @command{nano} will scroll just one line (instead of half
a screen) when the cursor is moved to a line that is just out of view.
And when paging up or down, @command{nano} keeps the cursor in the same
screen position as much as possible, instead of always placing it on the
first line of the viewport.  The Pico-like behavior can be obtained
with the @option{--jumpyscrolling} option.

@item Edit Area
Pico never uses the line directly below the title bar, leaving it always
blank.  @command{nano} includes this line in the editing area, in order
to not waste space, and because in this way it is slightly clearer where
the text starts.  If you are accustomed to this line being empty, you can
get it back with the @option{--emptyline} option.

@item Interactive Replace
Instead of allowing you to replace either just one occurrence of a search
string or all of them, @command{nano}'s replace function is interactive: it
will pause at each found search string and query whether to replace this
instance.  You can then choose Yes, or No (skip this one), or All (don't
ask any more), or Cancel (stop with replacing).

@item Search and Replace History
When the option @option{-H} or @option{--historylog} is given (or set in
the a nanorc file), text entered as search or replace strings is stored.
These strings can be accessed with the up/down arrow keys, or you can
type the first few characters and then use @kbd{Tab} to cycle through the
matching strings.  A retrieved string can subsequently be edited.

@item Position History
When the option @option{-P} or @option{--positionlog} is given (or set in
a nanorc file), @command{nano} will store the position of the cursor
when you close a file, and will place the cursor in that position
again when you later reopen the file.

@item Current Cursor Position
The output of the "Display Cursor Position" command (@kbd{^C}) displays
not only the current line and character position of the cursor,
but also (between the two) the current column position.

@item Spell Checking
In the internal spell checker misspelled words are sorted alphabetically
and trimmed for uniqueness, such that the words 'apple' and 'Apple' will
be prompted for correction separately.

@item Writing Selected Text to Files
When using the Write-Out key (@kbd{^O}), text that has been selected using the
marking key (@kbd{^^}) can not just be written out to a new (or existing) file,
it can also be appended or prepended to an existing file.

@item Reading Text from a Command
When using the Read-File key (@kbd{^R}), @command{nano} can not just read a file,
it can also read the output of a command to be run (@kbd{^X}).

@item Reading from Working Directory
By default, Pico will read files from the user's home directory (when
using @kbd{^R}), but it will write files to the current working directory
(when using @kbd{^O}).  @command{nano} makes this symmetrical: always reading
from and writing to the current working directory --- the directory
that @command{nano} was started in.

@item File Browser
In the file browser, @command{nano} does not implement the Add, Copy,
Rename, and Delete commands that Pico provides.  In @command{nano} the
browser is just a file browser, not a file manager.

@item Toggles
Many options which alter the functionality of the program can be
"toggled" on or off using Meta key sequences, meaning the program does
not have to be restarted to turn a particular feature on or off.
@xref{Feature Toggles} for a list of options that can be toggled.
Or see the list at the end of the main internal help text (@kbd{^G}) instead.

@end table


@node Building and Configure Options
@chapter Building and Configure Options

Building @command{nano} from source is fairly straightforward if you are
familiar with compiling programs with autoconf support:

@iftex
@sp 1
@end iftex
@example
  tar xvzf nano-x.y.z.tar.gz
  cd nano-x.y.z
  ./configure
  make
  make install
@end example
@iftex
@sp 1
@end iftex

The possible options to @code{./configure} are:

@table @code

@item --disable-browser
Exclude the mini file browser that can be called with @kbd{^T} when
wanting to read or write a file.

@item --disable-color
Exclude support for syntax coloring.  This also eliminates the @option{-Y}
command-line option, which allows choosing a specific syntax.

@item --disable-comment
Exclude the single-keystroke comment/uncomment function (@kbd{M-3}).

@item --disable-extra
Exclude the Easter egg: a crawl of major contributors.

@item --disable-help
Exclude the help texts (@kbd{^G}).  This makes the binary much smaller,
but also makes it difficult for new users to learn more than very basic
things about using the editor.

@item --disable-histories
Exclude the code for handling the history files: the search and
replace strings that were used, and the cursor position at which each
file was closed.  This also eliminates the @option{-H} and @option{-P}
command-line options, which switch on the logging of search/replace
strings and cursor positions.

@item --disable-justify
Exclude the justify functions (@kbd{^J} and @kbd{M-J}).

@item --disable-libmagic
Exclude the code for using the library of magic-number tests (for determining
the file type and thus which syntax to use for coloring --- often the regexes
for filename and header line will be enough).

@item --disable-linenumbers
Exclude the line-numbering function (@kbd{M-N}).  This also eliminates the
@option{-l} command-line option, which turns line numbering on.

@item --disable-mouse
Exclude all mouse functionality.  This also eliminates the @option{-m}
command-line option, which enables the mouse functionality.

@item --disable-multibuffer
Exclude support for opening multiple files at a time and switching
between them on the fly.  This also eliminates the @option{-F} command-line
option, which causes a file to be read into a separate buffer by default.

@item --disable-nanorc
Exclude support for reading the nanorc files at startup.  With such
support, you can store custom settings in a system-wide and a per-user
nanorc file rather than having to pass command-line options to get
the desired behavior.  @xref{Nanorc Files} for more info.
Disabling this also eliminates the @option{-I} command-line option,
which inhibits the reading of nanorc files.

@item --disable-operatingdir
Exclude the code for setting the operating directory.  This also eliminates
the @option{-o} command-line option, which sets the operating directory.

@item --disable-speller
Exclude the code for spell checking.  This also eliminates the @option{-s}
command-line option, which allows specifying an alternate spell checker.

@item --disable-tabcomp
Exclude tab completion (when nano asks for a filename or a search string).

@item --disable-wordcomp
Exclude word completion (@kbd{^]}).

@item --disable-wrapping
Exclude all hard-wrapping of overlong lines.  This also eliminates the
@option{-b} and @option{-w} command-line options, which switch automatic
long-line wrapping on and off, respectively.

@item --enable-tiny
This option implies all of the above.  It also disables some other
internals of the editor, like the marking code, the cut-to-end-of-line
code, and the function toggles.  By using the enabling
counterpart of the above options together with @option{--enable-tiny},
specific features can be switched back on --- but a few cannot.

@item --enable-debug
Include some code for runtime debugging output.  This can get pretty messy, so
chances are you only want this feature when you're working on the nano source.

@item --disable-nls
Exclude Native Language support.  This will disable the use of any
available GNU @command{nano} translations.

@item --enable-utf8
Include support for reading and writing Unicode files.
This requires a wide version of the curses library.

@item --disable-utf8
Exclude support for reading and writing Unicode files.  Normally the
configure script auto-detects whether to enable UTF-8 support or not.
You can use this or the previous option to override that detection.

@item --enable-altrcname=@var{name}
Use the file with the given @var{name} (in the user's home directory)
as nano's settings file, instead of the default @code{.nanorc}.

@end table

@html
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@contents

@bye