emacs-12   [plain text]


This is ../info/emacs, produced by makeinfo version 4.0 from emacs.texi.

   This is the thirteenth edition of the `GNU Emacs Manual', updated
for Emacs version 20.7.

INFO-DIR-SECTION Editors
START-INFO-DIR-ENTRY
* Emacs: (emacs).	The extensible self-documenting text editor.
END-INFO-DIR-ENTRY

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File: emacs,  Node: Filling,  Next: Case,  Prev: Pages,  Up: Text

Filling Text
============

   "Filling" text means breaking it up into lines that fit a specified
width.  Emacs does filling in two ways.  In Auto Fill mode, inserting
text with self-inserting characters also automatically fills it.  There
are also explicit fill commands that you can use when editing text
leaves it unfilled.  When you edit formatted text, you can specify a
style of filling for each portion of the text (*note Formatted Text::).

* Menu:

* Auto Fill::	        Auto Fill mode breaks long lines automatically.
* Fill Commands::       Commands to refill paragraphs and center lines.
* Fill Prefix::	        Filling paragraphs that are indented
                          or in a comment, etc.
* Adaptive Fill::       How Emacs can determine the fill prefix automatically.


File: emacs,  Node: Auto Fill,  Next: Fill Commands,  Up: Filling

Auto Fill Mode
--------------

   "Auto Fill" mode is a minor mode in which lines are broken
automatically when they become too wide.  Breaking happens only when
you type a <SPC> or <RET>.

`M-x auto-fill-mode'
     Enable or disable Auto Fill mode.

`<SPC>'
`<RET>'
     In Auto Fill mode, break lines when appropriate.

   `M-x auto-fill-mode' turns Auto Fill mode on if it was off, or off
if it was on.  With a positive numeric argument it always turns Auto
Fill mode on, and with a negative argument always turns it off.  You can
see when Auto Fill mode is in effect by the presence of the word `Fill'
in the mode line, inside the parentheses.  Auto Fill mode is a minor
mode which is enabled or disabled for each buffer individually.  *Note
Minor Modes::.

   In Auto Fill mode, lines are broken automatically at spaces when they
get longer than the desired width.  Line breaking and rearrangement
takes place only when you type <SPC> or <RET>.  If you wish to insert a
space or newline without permitting line-breaking, type `C-q <SPC>' or
`C-q C-j' (recall that a newline is really a control-J).  Also, `C-o'
inserts a newline without line breaking.

   Auto Fill mode works well with programming-language modes, because it
indents new lines with <TAB>.  If a line ending in a comment gets too
long, the text of the comment is split into two comment lines.
Optionally, new comment delimiters are inserted at the end of the first
line and the beginning of the second so that each line is a separate
comment; the variable `comment-multi-line' controls the choice (*note
Comments::).

   Adaptive filling (see the following section) works for Auto Filling
as well as for explicit fill commands.  It takes a fill prefix
automatically from the second or first line of a paragraph.

   Auto Fill mode does not refill entire paragraphs; it can break lines
but cannot merge lines.  So editing in the middle of a paragraph can
result in a paragraph that is not correctly filled.  The easiest way to
make the paragraph properly filled again is usually with the explicit
fill commands.  *Note Fill Commands::.

   Many users like Auto Fill mode and want to use it in all text files.
The section on init files says how to arrange this permanently for
yourself.  *Note Init File::.


File: emacs,  Node: Fill Commands,  Next: Fill Prefix,  Prev: Auto Fill,  Up: Filling

Explicit Fill Commands
----------------------

`M-q'
     Fill current paragraph (`fill-paragraph').

`C-x f'
     Set the fill column (`set-fill-column').

`M-x fill-region'
     Fill each paragraph in the region (`fill-region').

`M-x fill-region-as-paragraph'
     Fill the region, considering it as one paragraph.

`M-s'
     Center a line.

   To refill a paragraph, use the command `M-q' (`fill-paragraph').
This operates on the paragraph that point is inside, or the one after
point if point is between paragraphs.  Refilling works by removing all
the line-breaks, then inserting new ones where necessary.

   To refill many paragraphs, use `M-x fill-region', which divides the
region into paragraphs and fills each of them.

   `M-q' and `fill-region' use the same criteria as `M-h' for finding
paragraph boundaries (*note Paragraphs::).  For more control, you can
use `M-x fill-region-as-paragraph', which refills everything between
point and mark.  This command deletes any blank lines within the
region, so separate blocks of text end up combined into one block.

   A numeric argument to `M-q' causes it to "justify" the text as well
as filling it.  This means that extra spaces are inserted to make the
right margin line up exactly at the fill column.  To remove the extra
spaces, use `M-q' with no argument.  (Likewise for `fill-region'.)
Another way to control justification, and choose other styles of
filling, is with the `justification' text property; see *Note Format
Justification::.

   The command `M-s' (`center-line') centers the current line within
the current fill column.  With an argument N, it centers N lines
individually and moves past them.

   The maximum line width for filling is in the variable `fill-column'.
Altering the value of `fill-column' makes it local to the current
buffer; until that time, the default value is in effect.  The default
is initially 70.  *Note Locals::.  The easiest way to set `fill-column'
is to use the command `C-x f' (`set-fill-column').  With a numeric
argument, it uses that as the new fill column.  With just `C-u' as
argument, it sets `fill-column' to the current horizontal position of
point.

   Emacs commands normally consider a period followed by two spaces or
by a newline as the end of a sentence; a period followed by just one
space indicates an abbreviation and not the end of a sentence.  To
preserve the distinction between these two ways of using a period, the
fill commands do not break a line after a period followed by just one
space.

   If the variable `sentence-end-double-space' is `nil', the fill
commands expect and leave just one space at the end of a sentence.
Ordinarily this variable is `t', so the fill commands insist on two
spaces for the end of a sentence, as explained above.  *Note
Sentences::.

   If the variable `colon-double-space' is non-`nil', the fill commands
put two spaces after a colon.


File: emacs,  Node: Fill Prefix,  Next: Adaptive Fill,  Prev: Fill Commands,  Up: Filling

The Fill Prefix
---------------

   To fill a paragraph in which each line starts with a special marker
(which might be a few spaces, giving an indented paragraph), you can use
the "fill prefix" feature.  The fill prefix is a string that Emacs
expects every line to start with, and which is not included in filling.
You can specify a fill prefix explicitly; Emacs can also deduce the
fill prefix automatically (*note Adaptive Fill::).

`C-x .'
     Set the fill prefix (`set-fill-prefix').

`M-q'
     Fill a paragraph using current fill prefix (`fill-paragraph').

`M-x fill-individual-paragraphs'
     Fill the region, considering each change of indentation as
     starting a new paragraph.

`M-x fill-nonuniform-paragraphs'
     Fill the region, considering only paragraph-separator lines as
     starting a new paragraph.

   To specify a fill prefix, move to a line that starts with the desired
prefix, put point at the end of the prefix, and give the command
`C-x .' (`set-fill-prefix').  That's a period after the `C-x'.  To turn
off the fill prefix, specify an empty prefix: type `C-x .' with point
at the beginning of a line.

   When a fill prefix is in effect, the fill commands remove the fill
prefix from each line before filling and insert it on each line after
filling.  Auto Fill mode also inserts the fill prefix automatically when
it makes a new line.  The `C-o' command inserts the fill prefix on new
lines it creates, when you use it at the beginning of a line (*note
Blank Lines::).  Conversely, the command `M-^' deletes the prefix (if
it occurs) after the newline that it deletes (*note Indentation::).

   For example, if `fill-column' is 40 and you set the fill prefix to
`;; ', then `M-q' in the following text

     ;; This is an
     ;; example of a paragraph
     ;; inside a Lisp-style comment.

produces this:

     ;; This is an example of a paragraph
     ;; inside a Lisp-style comment.

   Lines that do not start with the fill prefix are considered to start
paragraphs, both in `M-q' and the paragraph commands; this gives good
results for paragraphs with hanging indentation (every line indented
except the first one).  Lines which are blank or indented once the
prefix is removed also separate or start paragraphs; this is what you
want if you are writing multi-paragraph comments with a comment
delimiter on each line.

   You can use `M-x fill-individual-paragraphs' to set the fill prefix
for each paragraph automatically.  This command divides the region into
paragraphs, treating every change in the amount of indentation as the
start of a new paragraph, and fills each of these paragraphs.  Thus,
all the lines in one "paragraph" have the same amount of indentation.
That indentation serves as the fill prefix for that paragraph.

   `M-x fill-nonuniform-paragraphs' is a similar command that divides
the region into paragraphs in a different way.  It considers only
paragraph-separating lines (as defined by `paragraph-separate') as
starting a new paragraph.  Since this means that the lines of one
paragraph may have different amounts of indentation, the fill prefix
used is the smallest amount of indentation of any of the lines of the
paragraph.  This gives good results with styles that indent a
paragraph's first line more or less that the rest of the paragraph.

   The fill prefix is stored in the variable `fill-prefix'.  Its value
is a string, or `nil' when there is no fill prefix.  This is a
per-buffer variable; altering the variable affects only the current
buffer, but there is a default value which you can change as well.
*Note Locals::.

   The `indentation' text property provides another way to control the
amount of indentation paragraphs receive.  *Note Format Indentation::.


File: emacs,  Node: Adaptive Fill,  Prev: Fill Prefix,  Up: Filling

Adaptive Filling
----------------

   The fill commands can deduce the proper fill prefix for a paragraph
automatically in certain cases: either whitespace or certain punctuation
characters at the beginning of a line are propagated to all lines of the
paragraph.

   If the paragraph has two or more lines, the fill prefix is taken from
the paragraph's second line, but only if it appears on the first line as
well.

   If a paragraph has just one line, fill commands _may_ take a prefix
from that line.  The decision is complicated because there are three
reasonable things to do in such a case:

   * Use the first line's prefix on all the lines of the paragraph.

   * Indent subsequent lines with whitespace, so that they line up
     under the text that follows the prefix on the first line, but
     don't actually copy the prefix from the first line.

   * Don't do anything special with the second and following lines.

   All three of these styles of formatting are commonly used.  So the
fill commands try to determine what you would like, based on the prefix
that appears and on the major mode.  Here is how.

   If the prefix found on the first line matches
`adaptive-fill-first-line-regexp', or if it appears to be a
comment-starting sequence (this depends on the major mode), then the
prefix found is used for filling the paragraph, provided it would not
act as a paragraph starter on subsequent lines.

   Otherwise, the prefix found is converted to an equivalent number of
spaces, and those spaces are used as the fill prefix for the rest of the
lines, provided they would not act as a paragraph starter on subsequent
lines.

   In Text mode, and other modes where only blank lines and page
delimiters separate paragraphs, the prefix chosen by adaptive filling
never acts as a paragraph starter, so it can always be used for filling.

   The variable `adaptive-fill-regexp' determines what kinds of line
beginnings can serve as a fill prefix: any characters at the start of
the line that match this regular expression are used.  If you set the
variable `adaptive-fill-mode' to `nil', the fill prefix is never chosen
automatically.

   You can specify more complex ways of choosing a fill prefix
automatically by setting the variable `adaptive-fill-function' to a
function.  This function is called with point after the left margin of a
line, and it should return the appropriate fill prefix based on that
line.  If it returns `nil', that means it sees no fill prefix in that
line.


File: emacs,  Node: Case,  Next: Text Mode,  Prev: Filling,  Up: Text

Case Conversion Commands
========================

   Emacs has commands for converting either a single word or any
arbitrary range of text to upper case or to lower case.

`M-l'
     Convert following word to lower case (`downcase-word').

`M-u'
     Convert following word to upper case (`upcase-word').

`M-c'
     Capitalize the following word (`capitalize-word').

`C-x C-l'
     Convert region to lower case (`downcase-region').

`C-x C-u'
     Convert region to upper case (`upcase-region').

   The word conversion commands are the most useful.  `M-l'
(`downcase-word') converts the word after point to lower case, moving
past it.  Thus, repeating `M-l' converts successive words.  `M-u'
(`upcase-word') converts to all capitals instead, while `M-c'
(`capitalize-word') puts the first letter of the word into upper case
and the rest into lower case.  All these commands convert several words
at once if given an argument.  They are especially convenient for
converting a large amount of text from all upper case to mixed case,
because you can move through the text using `M-l', `M-u' or `M-c' on
each word as appropriate, occasionally using `M-f' instead to skip a
word.

   When given a negative argument, the word case conversion commands
apply to the appropriate number of words before point, but do not move
point.  This is convenient when you have just typed a word in the wrong
case: you can give the case conversion command and continue typing.

   If a word case conversion command is given in the middle of a word,
it applies only to the part of the word which follows point.  This is
just like what `M-d' (`kill-word') does.  With a negative argument,
case conversion applies only to the part of the word before point.

   The other case conversion commands are `C-x C-u' (`upcase-region')
and `C-x C-l' (`downcase-region'), which convert everything between
point and mark to the specified case.  Point and mark do not move.

   The region case conversion commands `upcase-region' and
`downcase-region' are normally disabled.  This means that they ask for
confirmation if you try to use them.  When you confirm, you may enable
the command, which means it will not ask for confirmation again.  *Note
Disabling::.


File: emacs,  Node: Text Mode,  Next: Outline Mode,  Prev: Case,  Up: Text

Text Mode
=========

   When you edit files of text in a human language, it's more convenient
to use Text mode rather than Fundamental mode.  To enter Text mode, type
`M-x text-mode'.

   In Text mode, only blank lines and page delimiters separate
paragraphs.  As a result, paragraphs can be indented, and adaptive
filling determines what indentation to use when filling a paragraph.
*Note Adaptive Fill::.

   Text mode defines <TAB> to run `indent-relative' (*note
Indentation::), so that you can conveniently indent a line like the
previous line.  When the previous line is not indented,
`indent-relative' runs `tab-to-tab-stop', which uses Emacs tab stops
that you can set (*note Tab Stops::).

   Text mode turns off the features concerned with comments except when
you explicitly invoke them.  It changes the syntax table so that periods
are not considered part of a word, while apostrophes, backspaces and
underlines are considered part of words.

   If you indent the first lines of paragraphs, then you should use
Paragraph-Indent Text mode rather than Text mode.  In this mode, you do
not need to have blank lines between paragraphs, because the first-line
indentation is sufficient to start a paragraph; however paragraphs in
which every line is indented are not supported.  Use `M-x
paragraph-indent-text-mode' to enter this mode.

   Text mode, and all the modes based on it, define `M-<TAB>' as the
command `ispell-complete-word', which performs completion of the
partial word in the buffer before point, using the spelling dictionary
as the space of possible words.  *Note Spelling::.

   Entering Text mode runs the hook `text-mode-hook'.  Other major
modes related to Text mode also run this hook, followed by hooks of
their own; this includes Paragraph-Indent Text mode, Nroff mode, TeX
mode, Outline mode, and Mail mode.  Hook functions on `text-mode-hook'
can look at the value of `major-mode' to see which of these modes is
actually being entered.  *Note Hooks::.

   Emacs provides two other modes for editing text that is to be passed
through a text formatter to produce fancy formatted printed output.
*Note Nroff Mode::, for editing input to the formatter nroff.  *Note
TeX Mode::, for editing input to the formatter TeX.

   Another mode is used for editing outlines.  It allows you to view the
text at various levels of detail.  You can view either the outline
headings alone or both headings and text; you can also hide some of the
headings at lower levels from view to make the high level structure more
visible.  *Note Outline Mode::.


File: emacs,  Node: Outline Mode,  Next: TeX Mode,  Prev: Text Mode,  Up: Text

Outline Mode
============

   Outline mode is a major mode much like Text mode but intended for
editing outlines.  It allows you to make parts of the text temporarily
invisible so that you can see the outline structure.  Type `M-x
outline-mode' to switch to Outline mode as the major mode of the current
buffer.

   When Outline mode makes a line invisible, the line does not appear on
the screen.  The screen appears exactly as if the invisible line were
deleted, except that an ellipsis (three periods in a row) appears at the
end of the previous visible line (only one ellipsis no matter how many
invisible lines follow).

   Editing commands that operate on lines, such as `C-n' and `C-p',
treat the text of the invisible line as part of the previous visible
line.  Killing an entire visible line, including its terminating
newline, really kills all the following invisible lines along with it.

   Outline minor mode provides the same commands as the major mode,
Outline mode, but you can use it in conjunction with other major modes.
Type `M-x outline-minor-mode' to enable the Outline minor mode in the
current buffer.  You can also specify this in the text of a file, with
a file local variable of the form `mode: outline-minor' (*note File
Variables::).

   The major mode, Outline mode, provides special key bindings on the
`C-c' prefix.  Outline minor mode provides similar bindings with `C-c
@' as the prefix; this is to reduce the conflicts with the major mode's
special commands.  (The variable `outline-minor-mode-prefix' controls
the prefix used.)

   Entering Outline mode runs the hook `text-mode-hook' followed by the
hook `outline-mode-hook' (*note Hooks::).

* Menu:

* Format: Outline Format.	   What the text of an outline looks like.
* Motion: Outline Motion.	   Special commands for moving through
                                     outlines.
* Visibility: Outline Visibility.  Commands to control what is visible.
* Views: Outline Views.            Outlines and multiple views.


File: emacs,  Node: Outline Format,  Next: Outline Motion,  Up: Outline Mode

Format of Outlines
------------------

   Outline mode assumes that the lines in the buffer are of two types:
"heading lines" and "body lines".  A heading line represents a topic in
the outline.  Heading lines start with one or more stars; the number of
stars determines the depth of the heading in the outline structure.
Thus, a heading line with one star is a major topic; all the heading
lines with two stars between it and the next one-star heading are its
subtopics; and so on.  Any line that is not a heading line is a body
line.  Body lines belong with the preceding heading line.  Here is an
example:

     * Food
     This is the body,
     which says something about the topic of food.
     
     ** Delicious Food
     This is the body of the second-level header.
     
     ** Distasteful Food
     This could have
     a body too, with
     several lines.
     
     *** Dormitory Food
     
     * Shelter
     Another first-level topic with its header line.

   A heading line together with all following body lines is called
collectively an "entry".  A heading line together with all following
deeper heading lines and their body lines is called a "subtree".

   You can customize the criterion for distinguishing heading lines by
setting the variable `outline-regexp'.  Any line whose beginning has a
match for this regexp is considered a heading line.  Matches that start
within a line (not at the left margin) do not count.  The length of the
matching text determines the level of the heading; longer matches make
a more deeply nested level.  Thus, for example, if a text formatter has
commands `@chapter', `@section' and `@subsection' to divide the
document into chapters and sections, you could make those lines count
as heading lines by setting `outline-regexp' to
`"@chap\\|@\\(sub\\)*section"'.  Note the trick: the two words
`chapter' and `section' are equally long, but by defining the regexp to
match only `chap' we ensure that the length of the text matched on a
chapter heading is shorter, so that Outline mode will know that
sections are contained in chapters.  This works as long as no other
command starts with `@chap'.

   It is possible to change the rule for calculating the level of a
heading line by setting the variable `outline-level'.  The value of
`outline-level' should be a function that takes no arguments and
returns the level of the current heading.  Some major modes such as C,
Nroff, and Emacs Lisp mode set this variable in order to work with
Outline minor mode.


File: emacs,  Node: Outline Motion,  Next: Outline Visibility,  Prev: Outline Format,  Up: Outline Mode

Outline Motion Commands
-----------------------

   Outline mode provides special motion commands that move backward and
forward to heading lines.

`C-c C-n'
     Move point to the next visible heading line
     (`outline-next-visible-heading').

`C-c C-p'
     Move point to the previous visible heading line
     (`outline-previous-visible-heading').

`C-c C-f'
     Move point to the next visible heading line at the same level as
     the one point is on (`outline-forward-same-level').

`C-c C-b'
     Move point to the previous visible heading line at the same level
     (`outline-backward-same-level').

`C-c C-u'
     Move point up to a lower-level (more inclusive) visible heading
     line (`outline-up-heading').

   `C-c C-n' (`outline-next-visible-heading') moves down to the next
heading line.  `C-c C-p' (`outline-previous-visible-heading') moves
similarly backward.  Both accept numeric arguments as repeat counts.
The names emphasize that invisible headings are skipped, but this is
not really a special feature.  All editing commands that look for lines
ignore the invisible lines automatically.

   More powerful motion commands understand the level structure of
headings.  `C-c C-f' (`outline-forward-same-level') and `C-c C-b'
(`outline-backward-same-level') move from one heading line to another
visible heading at the same depth in the outline.  `C-c C-u'
(`outline-up-heading') moves backward to another heading that is less
deeply nested.


File: emacs,  Node: Outline Visibility,  Next: Outline Views,  Prev: Outline Motion,  Up: Outline Mode

Outline Visibility Commands
---------------------------

   The other special commands of outline mode are used to make lines
visible or invisible.  Their names all start with `hide' or `show'.
Most of them fall into pairs of opposites.  They are not undoable;
instead, you can undo right past them.  Making lines visible or
invisible is simply not recorded by the undo mechanism.

`C-c C-t'
     Make all body lines in the buffer invisible (`hide-body').

`C-c C-a'
     Make all lines in the buffer visible (`show-all').

`C-c C-d'
     Make everything under this heading invisible, not including this
     heading itself (`hide-subtree').

`C-c C-s'
     Make everything under this heading visible, including body,
     subheadings, and their bodies (`show-subtree').

`C-c C-l'
     Make the body of this heading line, and of all its subheadings,
     invisible (`hide-leaves').

`C-c C-k'
     Make all subheadings of this heading line, at all levels, visible
     (`show-branches').

`C-c C-i'
     Make immediate subheadings (one level down) of this heading line
     visible (`show-children').

`C-c C-c'
     Make this heading line's body invisible (`hide-entry').

`C-c C-e'
     Make this heading line's body visible (`show-entry').

`C-c C-q'
     Hide everything except the top N levels of heading lines
     (`hide-sublevels').

`C-c C-o'
     Hide everything except for the heading or body that point is in,
     plus the headings leading up from there to the top level of the
     outline (`hide-other').

   Two commands that are exact opposites are `C-c C-c' (`hide-entry')
and `C-c C-e' (`show-entry').  They are used with point on a heading
line, and apply only to the body lines of that heading.  Subheadings
and their bodies are not affected.

   Two more powerful opposites are `C-c C-d' (`hide-subtree') and `C-c
C-s' (`show-subtree').  Both expect to be used when point is on a
heading line, and both apply to all the lines of that heading's
"subtree": its body, all its subheadings, both direct and indirect, and
all of their bodies.  In other words, the subtree contains everything
following this heading line, up to and not including the next heading of
the same or higher rank.

   Intermediate between a visible subtree and an invisible one is having
all the subheadings visible but none of the body.  There are two
commands for doing this, depending on whether you want to hide the
bodies or make the subheadings visible.  They are `C-c C-l'
(`hide-leaves') and `C-c C-k' (`show-branches').

   A little weaker than `show-branches' is `C-c C-i' (`show-children').
It makes just the direct subheadings visible--those one level down.
Deeper subheadings remain invisible, if they were invisible.

   Two commands have a blanket effect on the whole file.  `C-c C-t'
(`hide-body') makes all body lines invisible, so that you see just the
outline structure.  `C-c C-a' (`show-all') makes all lines visible.
These commands can be thought of as a pair of opposites even though
`C-c C-a' applies to more than just body lines.

   The command `C-c C-q' (`hide-sublevels') hides all but the top level
headings.  With a numeric argument N, it hides everything except the
top N levels of heading lines.

   The command `C-c C-o' (`hide-other') hides everything except the
heading or body text that point is in, plus its parents (the headers
leading up from there to top level in the outline).

   You can turn off the use of ellipses at the ends of visible lines by
setting `selective-display-ellipses' to `nil'.  Then there is no
visible indication of the presence of invisible lines.

   When incremental search finds text that is hidden by Outline mode,
it makes that part of the buffer visible.  If you exit the search at
that position, the text remains visible.


File: emacs,  Node: Outline Views,  Prev: Outline Visibility,  Up: Outline Mode

Viewing One Outline in Multiple Views
-------------------------------------

   You can display two views of a single outline at the same time, in
different windows.  To do this, you must create an indirect buffer using
`M-x make-indirect-buffer'.  The first argument of this command is the
existing outline buffer name, and its second argument is the name to
use for the new indirect buffer.  *Note Indirect Buffers::.

   Once the indirect buffer exists, you can display it in a window in
the normal fashion, with `C-x 4 b' or other Emacs commands.  The Outline
mode commands to show and hide parts of the text operate on each buffer
independently; as a result, each buffer can have its own view.  If you
want more than two views on the same outline, create additional indirect
buffers.


File: emacs,  Node: TeX Mode,  Next: Nroff Mode,  Prev: Outline Mode,  Up: Text

TeX Mode
========

   TeX is a powerful text formatter written by Donald Knuth; it is also
free, like GNU Emacs.  LaTeX is a simplified input format for TeX,
implemented by TeX macros; it comes with TeX.  SliTeX is a special form
of LaTeX.

   Emacs has a special TeX mode for editing TeX input files.  It
provides facilities for checking the balance of delimiters and for
invoking TeX on all or part of the file.

   TeX mode has three variants, Plain TeX mode, LaTeX mode, and SliTeX
mode (these three distinct major modes differ only slightly).  They are
designed for editing the three different formats.  The command `M-x
tex-mode' looks at the contents of the buffer to determine whether the
contents appear to be either LaTeX input or SliTeX input; if so, it
selects the appropriate mode.  If the file contents do not appear to be
LaTeX or SliTeX, it selects Plain TeX mode.  If the contents are
insufficient to determine this, the variable `tex-default-mode'
controls which mode is used.

   When `M-x tex-mode' does not guess right, you can use the commands
`M-x plain-tex-mode', `M-x latex-mode', and `M-x slitex-mode' to select
explicitly the particular variants of TeX mode.

* Menu:

* Editing: TeX Editing.   Special commands for editing in TeX mode.
* LaTeX: LaTeX Editing.   Additional commands for LaTeX input files.
* Printing: TeX Print.    Commands for printing part of a file with TeX.


File: emacs,  Node: TeX Editing,  Next: LaTeX Editing,  Up: TeX Mode

TeX Editing Commands
--------------------

   Here are the special commands provided in TeX mode for editing the
text of the file.

`"'
     Insert, according to context, either ```' or `"' or `'''
     (`tex-insert-quote').

`C-j'
     Insert a paragraph break (two newlines) and check the previous
     paragraph for unbalanced braces or dollar signs
     (`tex-terminate-paragraph').

`M-x tex-validate-region'
     Check each paragraph in the region for unbalanced braces or dollar
     signs.

`C-c {'
     Insert `{}' and position point between them (`tex-insert-braces').

`C-c }'
     Move forward past the next unmatched close brace (`up-list').

   In TeX, the character `"' is not normally used; we use ```' to start
a quotation and `''' to end one.  To make editing easier under this
formatting convention, TeX mode overrides the normal meaning of the key
`"' with a command that inserts a pair of single-quotes or backquotes
(`tex-insert-quote').  To be precise, this command inserts ```' after
whitespace or an open brace, `"' after a backslash, and `''' after any
other character.

   If you need the character `"' itself in unusual contexts, use `C-q'
to insert it.  Also, `"' with a numeric argument always inserts that
number of `"' characters.  You can turn off the feature of `"'
expansion by eliminating that binding in the local map (*note Key
Bindings::).

   In TeX mode, `$' has a special syntax code which attempts to
understand the way TeX math mode delimiters match.  When you insert a
`$' that is meant to exit math mode, the position of the matching `$'
that entered math mode is displayed for a second.  This is the same
feature that displays the open brace that matches a close brace that is
inserted.  However, there is no way to tell whether a `$' enters math
mode or leaves it; so when you insert a `$' that enters math mode, the
previous `$' position is shown as if it were a match, even though they
are actually unrelated.

   TeX uses braces as delimiters that must match.  Some users prefer to
keep braces balanced at all times, rather than inserting them singly.
Use `C-c {' (`tex-insert-braces') to insert a pair of braces.  It
leaves point between the two braces so you can insert the text that
belongs inside.  Afterward, use the command `C-c }' (`up-list') to move
forward past the close brace.

   There are two commands for checking the matching of braces.  `C-j'
(`tex-terminate-paragraph') checks the paragraph before point, and
inserts two newlines to start a new paragraph.  It prints a message in
the echo area if any mismatch is found.  `M-x tex-validate-region'
checks a region, paragraph by paragraph.  The errors are listed in the
`*Occur*' buffer, and you can use `C-c C-c' or `Mouse-2' in that buffer
to go to a particular mismatch.

   Note that Emacs commands count square brackets and parentheses in
TeX mode, not just braces.  This is not strictly correct for the
purpose of checking TeX syntax.  However, parentheses and square
brackets are likely to be used in text as matching delimiters and it is
useful for the various motion commands and automatic match display to
work with them.


File: emacs,  Node: LaTeX Editing,  Next: TeX Print,  Prev: TeX Editing,  Up: TeX Mode

LaTeX Editing Commands
----------------------

   LaTeX mode, and its variant, SliTeX mode, provide a few extra
features not applicable to plain TeX.

`C-c C-o'
     Insert `\begin' and `\end' for LaTeX block and position point on a
     line between them (`tex-latex-block').

`C-c C-e'
     Close the innermost LaTeX block not yet closed
     (`tex-close-latex-block').

   In LaTeX input, `\begin' and `\end' commands are used to group
blocks of text.  To insert a `\begin' and a matching `\end' (on a new
line following the `\begin'), use `C-c C-o' (`tex-latex-block').  A
blank line is inserted between the two, and point is left there.  You
can use completion when you enter the block type; to specify additional
block type names beyond the standard list, set the variable
`latex-block-names'.  For example, here's how to add `theorem',
`corollary', and `proof':

     (setq latex-block-names '("theorem" "corollary" "proof"))

   In LaTeX input, `\begin' and `\end' commands must balance.  You can
use `C-c C-e' (`tex-close-latex-block') to insert automatically a
matching `\end' to match the last unmatched `\begin'.  It indents the
`\end' to match the corresponding `\begin'.  It inserts a newline after
`\end' if point is at the beginning of a line.


File: emacs,  Node: TeX Print,  Prev: LaTeX Editing,  Up: TeX Mode

TeX Printing Commands
---------------------

   You can invoke TeX as an inferior of Emacs on either the entire
contents of the buffer or just a region at a time.  Running TeX in this
way on just one chapter is a good way to see what your changes look
like without taking the time to format the entire file.

`C-c C-r'
     Invoke TeX on the current region, together with the buffer's header
     (`tex-region').

`C-c C-b'
     Invoke TeX on the entire current buffer (`tex-buffer').

`C-c <TAB>'
     Invoke BibTeX on the current file (`tex-bibtex-file').

`C-c C-f'
     Invoke TeX on the current file (`tex-file').

`C-c C-l'
     Recenter the window showing output from the inferior TeX so that
     the last line can be seen (`tex-recenter-output-buffer').

`C-c C-k'
     Kill the TeX subprocess (`tex-kill-job').

`C-c C-p'
     Print the output from the last `C-c C-r', `C-c C-b', or `C-c C-f'
     command (`tex-print').

`C-c C-v'
     Preview the output from the last `C-c C-r', `C-c C-b', or `C-c
     C-f' command (`tex-view').

`C-c C-q'
     Show the printer queue (`tex-show-print-queue').

   You can pass the current buffer through an inferior TeX by means of
`C-c C-b' (`tex-buffer').  The formatted output appears in a temporary
file; to print it, type `C-c C-p' (`tex-print').  Afterward, you can
use `C-c C-q' (`tex-show-print-queue') to view the progress of your
output towards being printed.  If your terminal has the ability to
display TeX output files, you can preview the output on the terminal
with `C-c C-v' (`tex-view').

   You can specify the directory to use for running TeX by setting the
variable `tex-directory'.  `"."' is the default value.  If your
environment variable `TEXINPUTS' contains relative directory names, or
if your files contains `\input' commands with relative file names, then
`tex-directory' _must_ be `"."' or you will get the wrong results.
Otherwise, it is safe to specify some other directory, such as `"/tmp"'.

   If you want to specify which shell commands are used in the inferior
TeX, you can do so by setting the values of the variables
`tex-run-command', `latex-run-command', `slitex-run-command',
`tex-dvi-print-command', `tex-dvi-view-command', and
`tex-show-queue-command'.  You _must_ set the value of
`tex-dvi-view-command' for your particular terminal; this variable has
no default value.  The other variables have default values that may (or
may not) be appropriate for your system.

   Normally, the file name given to these commands comes at the end of
the command string; for example, `latex FILENAME'.  In some cases,
however, the file name needs to be embedded in the command; an example
is when you need to provide the file name as an argument to one command
whose output is piped to another.  You can specify where to put the
file name with `*' in the command string.  For example,

     (setq tex-dvi-print-command "dvips -f * | lpr")

   The terminal output from TeX, including any error messages, appears
in a buffer called `*tex-shell*'.  If TeX gets an error, you can switch
to this buffer and feed it input (this works as in Shell mode; *note
Interactive Shell::).  Without switching to this buffer you can scroll
it so that its last line is visible by typing `C-c C-l'.

   Type `C-c C-k' (`tex-kill-job') to kill the TeX process if you see
that its output is no longer useful.  Using `C-c C-b' or `C-c C-r' also
kills any TeX process still running.

   You can also pass an arbitrary region through an inferior TeX by
typing `C-c C-r' (`tex-region').  This is tricky, however, because most
files of TeX input contain commands at the beginning to set parameters
and define macros, without which no later part of the file will format
correctly.  To solve this problem, `C-c C-r' allows you to designate a
part of the file as containing essential commands; it is included before
the specified region as part of the input to TeX.  The designated part
of the file is called the "header".

   To indicate the bounds of the header in Plain TeX mode, you insert
two special strings in the file.  Insert `%**start of header' before the
header, and `%**end of header' after it.  Each string must appear
entirely on one line, but there may be other text on the line before or
after.  The lines containing the two strings are included in the header.
If `%**start of header' does not appear within the first 100 lines of
the buffer, `C-c C-r' assumes that there is no header.

   In LaTeX mode, the header begins with `\documentstyle' and ends with
`\begin{document}'.  These are commands that LaTeX requires you to use
in any case, so nothing special needs to be done to identify the header.

   The commands (`tex-buffer') and (`tex-region') do all of their work
in a temporary directory, and do not have available any of the auxiliary
files needed by TeX for cross-references; these commands are generally
not suitable for running the final copy in which all of the
cross-references need to be correct.

   When you want the auxiliary files for cross references, use `C-c
C-f' (`tex-file') which runs TeX on the current buffer's file, in that
file's directory.  Before running TeX, it offers to save any modified
buffers.  Generally, you need to use (`tex-file') twice to get the
cross-references right.

   The value of the variable `tex-start-options-string' specifies
options for the TeX run.  The default value causes TeX to run in
nonstopmode.  To run TeX interactively, set the variable to `""'.

   Large TeX documents are often split into several files--one main
file, plus subfiles.  Running TeX on a subfile typically does not work;
you have to run it on the main file.  In order to make `tex-file'
useful when you are editing a subfile, you can set the variable
`tex-main-file' to the name of the main file.  Then `tex-file' runs TeX
on that file.

   The most convenient way to use `tex-main-file' is to specify it in a
local variable list in each of the subfiles.  *Note File Variables::.

   For LaTeX files, you can use BibTeX to process the auxiliary file
for the current buffer's file.  BibTeX looks up bibliographic citations
in a data base and prepares the cited references for the bibliography
section.  The command `C-c TAB' (`tex-bibtex-file') runs the shell
command (`tex-bibtex-command') to produce a `.bbl' file for the current
buffer's file.  Generally, you need to do `C-c C-f' (`tex-file') once
to generate the `.aux' file, then do `C-c TAB' (`tex-bibtex-file'), and
then repeat `C-c C-f' (`tex-file') twice more to get the
cross-references correct.

   Entering any kind of TeX mode runs the hooks `text-mode-hook' and
`tex-mode-hook'.  Then it runs either `plain-tex-mode-hook' or
`latex-mode-hook', whichever is appropriate.  For SliTeX files, it
calls `slitex-mode-hook'.  Starting the TeX shell runs the hook
`tex-shell-hook'.  *Note Hooks::.


File: emacs,  Node: Nroff Mode,  Next: Formatted Text,  Prev: TeX Mode,  Up: Text

Nroff Mode
==========

   Nroff mode is a mode like Text mode but modified to handle nroff
commands present in the text.  Invoke `M-x nroff-mode' to enter this
mode.  It differs from Text mode in only a few ways.  All nroff command
lines are considered paragraph separators, so that filling will never
garble the nroff commands.  Pages are separated by `.bp' commands.
Comments start with backslash-doublequote.  Also, three special
commands are provided that are not in Text mode:

`M-n'
     Move to the beginning of the next line that isn't an nroff command
     (`forward-text-line').  An argument is a repeat count.

`M-p'
     Like `M-n' but move up (`backward-text-line').

`M-?'
     Prints in the echo area the number of text lines (lines that are
     not nroff commands) in the region (`count-text-lines').

   The other feature of Nroff mode is that you can turn on Electric
Nroff mode.  This is a minor mode that you can turn on or off with `M-x
electric-nroff-mode' (*note Minor Modes::).  When the mode is on, each
time you use <RET> to end a line that contains an nroff command that
opens a kind of grouping, the matching nroff command to close that
grouping is automatically inserted on the following line.  For example,
if you are at the beginning of a line and type `. ( b <RET>', this
inserts the matching command `.)b' on a new line following point.

   If you use Outline minor mode with Nroff mode (*note Outline Mode::),
heading lines are lines of the form `.H' followed by a number (the
header level).

   Entering Nroff mode runs the hook `text-mode-hook', followed by the
hook `nroff-mode-hook' (*note Hooks::).


File: emacs,  Node: Formatted Text,  Prev: Nroff Mode,  Up: Text

Editing Formatted Text
======================

   "Enriched mode" is a minor mode for editing files that contain
formatted text in WYSIWYG fashion, as in a word processor.  Currently,
formatted text in Enriched mode can specify fonts, colors, underlining,
margins, and types of filling and justification.  In the future, we plan
to implement other formatting features as well.

   Enriched mode is a minor mode (*note Minor Modes::).  Typically it is
used in conjunction with Text mode (*note Text Mode::).  However, you
can also use it with other major modes such as Outline mode and
Paragraph-Indent Text mode.

   Potentially, Emacs can store formatted text files in various file
formats.  Currently, only one format is implemented: "text/enriched"
format, which is defined by the MIME protocol.  *Note Format
Conversion: (elisp)Format Conversion, for details of how Emacs
recognizes and converts file formats.

   The Emacs distribution contains a formatted text file that can serve
as an example.  Its name is `etc/enriched.doc'.  It contains samples
illustrating all the features described in this section.  It also
contains a list of ideas for future enhancements.

* Menu:

* Requesting Formatted Text::   Entering and exiting Enriched mode.
* Hard and Soft Newlines::      There are two different kinds of newlines.
* Editing Format Info::         How to edit text properties.
* Faces: Format Faces.          Bold, italic, underline, etc.
* Color: Format Colors.         Changing the color of text.
* Indent: Format Indentation.   Changing the left and right margins.
* Justification: Format Justification.
                                Centering, setting text flush with the
                                  left or right margin, etc.
* Other: Format Properties.     The "special" text properties submenu.
* Forcing Enriched Mode::       How to force use of Enriched mode.


File: emacs,  Node: Requesting Formatted Text,  Next: Hard and Soft Newlines,  Up: Formatted Text

Requesting to Edit Formatted Text
---------------------------------

   Whenever you visit a file that Emacs saved in the text/enriched
format, Emacs automatically converts the formatting information in the
file into Emacs's own internal format (text properties), and turns on
Enriched mode.

   To create a new file of formatted text, first visit the nonexistent
file, then type `M-x enriched-mode' before you start inserting text.
This command turns on Enriched mode.  Do this before you begin inserting
text, to ensure that the text you insert is handled properly.

   More generally, the command `enriched-mode' turns Enriched mode on
if it was off, and off if it was on.  With a prefix argument, this
command turns Enriched mode on if the argument is positive, and turns
the mode off otherwise.

   When you save a buffer while Enriched mode is enabled in it, Emacs
automatically converts the text to text/enriched format while writing it
into the file.  When you visit the file again, Emacs will automatically
recognize the format, reconvert the text, and turn on Enriched mode
again.

   Normally, after visiting a file in text/enriched format, Emacs
refills each paragraph to fit the specified right margin.  You can turn
off this refilling, to save time, by setting the variable
`enriched-fill-after-visiting' to `nil' or to `ask'.

   However, when visiting a file that was saved from Enriched mode,
there is no need for refilling, because Emacs saves the right margin
settings along with the text.

   You can add annotations for saving additional text properties, which
Emacs normally does not save, by adding to `enriched-translations'.
Note that the text/enriched standard requires any non-standard
annotations to have names starting with `x-', as in `x-read-only'.
This ensures that they will not conflict with standard annotations that
may be added later.


File: emacs,  Node: Hard and Soft Newlines,  Next: Editing Format Info,  Prev: Requesting Formatted Text,  Up: Formatted Text

Hard and Soft Newlines
----------------------

   In formatted text, Emacs distinguishes between two different kinds of
newlines, "hard" newlines and "soft" newlines.

   Hard newlines are used to separate paragraphs, or items in a list, or
anywhere that there should always be a line break regardless of the
margins.  The <RET> command (`newline') and `C-o' (`open-line') insert
hard newlines.

   Soft newlines are used to make text fit between the margins.  All the
fill commands, including Auto Fill, insert soft newlines--and they
delete only soft newlines.

   Although hard and soft newlines look the same, it is important to
bear the difference in mind.  Do not use <RET> to break lines in the
middle of filled paragraphs, or else you will get hard newlines that are
barriers to further filling.  Instead, let Auto Fill mode break lines,
so that if the text or the margins change, Emacs can refill the lines
properly.  *Note Auto Fill::.

   On the other hand, in tables and lists, where the lines should always
remain as you type them, you can use <RET> to end lines.  For these
lines, you may also want to set the justification style to `unfilled'.
*Note Format Justification::.


File: emacs,  Node: Editing Format Info,  Next: Format Faces,  Prev: Hard and Soft Newlines,  Up: Formatted Text

Editing Format Information
--------------------------

   There are two ways to alter the formatting information for a
formatted text file: with keyboard commands, and with the mouse.

   The easiest way to add properties to your document is by using the
Text Properties menu.  You can get to this menu in two ways: from the
Edit menu in the menu bar, or with `C-mouse-2' (hold the <CTRL> key and
press the middle mouse button).

   Most of the items in the Text Properties menu lead to other submenus.
These are described in the sections that follow.  Some items run
commands directly:

`Remove Properties'
     Delete from the region all the text properties that the Text
     Properties menu works with (`facemenu-remove-props').

`Remove All'
     Delete _all_ text properties from the region
     (`facemenu-remove-all').

`List Properties'
     List all the text properties of the character following point
     (`list-text-properties-at').

`Display Faces'
     Display a list of all the defined faces.

`Display Colors'
     Display a list of all the defined colors.