@c This is part of the Emacs manual.
@c Copyright (C) 1985, 1986, 1987, 1993, 1994 Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Text, Programs, Indentation, Top
@chapter Commands for Human Languages
@cindex text
@cindex manipulating text

  The term @dfn{text} has two widespread meanings in our area of the
computer field.  One is data that is a sequence of characters.  Any file
that you edit with Emacs is text, in this sense of the word.  The other
meaning is more restrictive: a sequence of characters in a human language
for humans to read (possibly after processing by a text formatter), as
opposed to a program or commands for a program.

  Human languages have syntactic/stylistic conventions that can be
supported or used to advantage by editor commands: conventions involving
words, sentences, paragraphs, and capital letters.  This chapter
describes Emacs commands for all of these things.  There are also
commands for @dfn{filling}, which means rearranging the lines of a
paragraph to be approximately equal in length.  The commands for moving
over and killing words, sentences and paragraphs, while intended
primarily for editing text, are also often useful for editing programs.

  Emacs has several major modes for editing human language text.  If the
file contains text pure and simple, use Text mode, which customizes
Emacs in small ways for the syntactic conventions of text.  For text
which contains embedded commands for text formatters, Emacs has other
major modes, each for a particular text formatter.  Thus, for input to
@TeX{}, you would use @TeX{} mode; for input to nroff, Nroff mode.
Outline mode provides special commands for operating on text with an
outline structure.

@menu
* Words::         Moving over and killing words.
* Sentences::     Moving over and killing sentences.
* Paragraphs::	  Moving over paragraphs.
* Pages::	  Moving over pages.
* Filling::       Filling or justifying text.
* Case::          Changing the case of text.
* Text Mode::     The major modes for editing text files.
* Outline Mode::  The major mode for editing outlines.
* TeX Mode::      The major modes for editing input to the formatter TeX.
* Nroff Mode::    The major mode for editing input to the formatter nroff.
@end menu

@node Words
@section Words
@cindex words
@cindex Meta commands and words

  Emacs has commands for moving over or operating on words.  By convention,
the keys for them are all Meta characters.

@c widecommands
@table @kbd
@item M-f
Move forward over a word (@code{forward-word}).
@item M-b
Move backward over a word (@code{backward-word}).
@item M-d
Kill up to the end of a word (@code{kill-word}).
@item M-@key{DEL}
Kill back to the beginning of a word (@code{backward-kill-word}).
@item M-@@
Mark the end of the next word (@code{mark-word}).
@item M-t
Transpose two words or drag a word across other words
(@code{transpose-words}).
@end table

  Notice how these keys form a series that parallels the
character-based @kbd{C-f}, @kbd{C-b}, @kbd{C-d}, @kbd{C-t} and
@key{DEL}.  @kbd{M-@@} is cognate to @kbd{C-@@}, which is an alias for
@kbd{C-@key{SPC}}.

@kindex M-f
@kindex M-b
@findex forward-word
@findex backward-word
  The commands @kbd{M-f} (@code{forward-word}) and @kbd{M-b}
(@code{backward-word}) move forward and backward over words.  These
Meta characters are thus analogous to the corresponding control
characters, @kbd{C-f} and @kbd{C-b}, which move over single characters
in the text.  The analogy extends to numeric arguments, which serve as
repeat counts.  @kbd{M-f} with a negative argument moves backward, and
@kbd{M-b} with a negative argument moves forward.  Forward motion
stops right after the last letter of the word, while backward motion
stops right before the first letter.@refill

@kindex M-d
@findex kill-word
  @kbd{M-d} (@code{kill-word}) kills the word after point.  To be
precise, it kills everything from point to the place @kbd{M-f} would
move to.  Thus, if point is in the middle of a word, @kbd{M-d} kills
just the part after point.  If some punctuation comes between point and the
next word, it is killed along with the word.  (If you wish to kill only the
next word but not the punctuation before it, simply do @kbd{M-f} to get
the end, and kill the word backwards with @kbd{M-@key{DEL}}.)
@kbd{M-d} takes arguments just like @kbd{M-f}.

@findex backward-kill-word
@kindex M-DEL
  @kbd{M-@key{DEL}} (@code{backward-kill-word}) kills the word before
point.  It kills everything from point back to where @kbd{M-b} would
move to.  If point is after the space in @w{@samp{FOO, BAR}}, then
@w{@samp{FOO, }} is killed.  (If you wish to kill just @samp{FOO}, do
@kbd{M-b M-d} instead of @kbd{M-@key{DEL}}.)

@kindex M-t
@findex transpose-words
  @kbd{M-t} (@code{transpose-words}) exchanges the word before or
containing point with the following word.  The delimiter characters between
the words do not move.  For example, @w{@samp{FOO, BAR}} transposes into
@w{@samp{BAR, FOO}} rather than @samp{@w{BAR FOO,}}.  @xref{Transpose}, for
more on transposition and on arguments to transposition commands.

@kindex M-@@
@findex mark-word
  To operate on the next @var{n} words with an operation which applies
between point and mark, you can either set the mark at point and then move
over the words, or you can use the command @kbd{M-@@} (@code{mark-word})
which does not move point, but sets the mark where @kbd{M-f} would move
to.  @kbd{M-@@} accepts a numeric argument that says how many words to
scan for the place to put the mark.  In Transient Mark mode, this command
activates the mark.

  The word commands' understanding of syntax is completely controlled by
the syntax table.  Any character can, for example, be declared to be a word
delimiter.  @xref{Syntax}.

@node Sentences
@section Sentences
@cindex sentences
@cindex manipulating sentences

  The Emacs commands for manipulating sentences and paragraphs are mostly
on Meta keys, so as to be like the word-handling commands.

@table @kbd
@item M-a
Move back to the beginning of the sentence (@code{backward-sentence}).
@item M-e
Move forward to the end of the sentence (@code{forward-sentence}).
@item M-k
Kill forward to the end of the sentence (@code{kill-sentence}).
@item C-x @key{DEL}
Kill back to the beginning of the sentence (@code{backward-kill-sentence}).
@end table

@kindex M-a
@kindex M-e
@findex backward-sentence
@findex forward-sentence
  The commands @kbd{M-a} and @kbd{M-e} (@code{backward-sentence} and
@code{forward-sentence}) move to the beginning and end of the current
sentence, respectively.  They were chosen to resemble @kbd{C-a} and
@kbd{C-e}, which move to the beginning and end of a line.  Unlike them,
@kbd{M-a} and @kbd{M-e} if repeated or given numeric arguments move over
successive sentences.

  Moving backward over a sentence places point just before the first
character of the sentence; moving forward places point right after the
punctuation that ends the sentence.  Neither one moves over the
whitespace at the sentence boundary.

@kindex M-k
@kindex C-x DEL
@findex kill-sentence
@findex backward-kill-sentence
  Just as @kbd{C-a} and @kbd{C-e} have a kill command, @kbd{C-k}, to go
with them, so @kbd{M-a} and @kbd{M-e} have a corresponding kill command
@kbd{M-k} (@code{kill-sentence}) which kills from point to the end of
the sentence.  With minus one as an argument it kills back to the
beginning of the sentence.  Larger arguments serve as a repeat count.
There is also a command, @kbd{C-x @key{DEL}}
(@code{backward-kill-sentence}), for killing back to the beginning of a
sentence.  This command is useful when you change your mind in the
middle of composing text.@refill

  The sentence commands assume that you follow the American typist's
convention of putting two spaces at the end of a sentence; they consider
a sentence to end wherever there is a @samp{.}, @samp{?} or @samp{!}
followed by the end of a line or two spaces, with any number of
@samp{)}, @samp{]}, @samp{'}, or @samp{"} characters allowed in between.
A sentence also begins or ends wherever a paragraph begins or ends.

@vindex sentence-end
  The variable @code{sentence-end} controls recognition of the end of a
sentence.  It is a regexp that matches the last few characters of a
sentence, together with the whitespace following the sentence.  Its
normal value is

@example
"[.?!][]\"')]*\\($\\|\t\\|  \\)[ \t\n]*"
@end example

@noindent
This example is explained in the section on regexps.  @xref{Regexps}.

  If you want to use just one space between sentences, you should
set @code{sentence-end} to this value:

@example
"[.?!][]\"')]*\\($\\|\t\\| \\)[ \t\n]*"
@end example

@noindent
You should also set the variable @code{sentence-end-double-space} to
@code{nil} so that the fill commands expect and leave just one space at
the end of a sentence.  Note that this makes it impossible to
distinguish between periods that end sentences and those that indicate
abbreviations.

@node Paragraphs
@section Paragraphs
@cindex paragraphs
@cindex manipulating paragraphs
@kindex M-@{
@kindex M-@}
@findex backward-paragraph
@findex forward-paragraph

  The Emacs commands for manipulating paragraphs are also Meta keys.

@table @kbd
@item M-@{
Move back to previous paragraph beginning (@code{backward-paragraph}).
@item M-@}
Move forward to next paragraph end (@code{forward-paragraph}).
@item M-h
Put point and mark around this or next paragraph (@code{mark-paragraph}).
@end table

  @kbd{M-@{} moves to the beginning of the current or previous
paragraph, while @kbd{M-@}} moves to the end of the current or next
paragraph.  Blank lines and text formatter command lines separate
paragraphs and are not considered part of any paragraph.  Also, an
indented line starts a new paragraph.

  In major modes for programs (as opposed to Text mode), paragraphs begin
and end only at blank lines.  This makes the paragraph commands continue to
be useful even though there are no paragraphs per se.

  When there is a fill prefix, then paragraphs are delimited by all lines
which don't start with the fill prefix.  @xref{Filling}.

@kindex M-h
@findex mark-paragraph
  When you wish to operate on a paragraph, you can use the command
@kbd{M-h} (@code{mark-paragraph}) to set the region around it.  Thus,
for example, @kbd{M-h C-w} kills the paragraph around or after point.
The @kbd{M-h} command puts point at the beginning and mark at the end of
the paragraph point was in.  In Transient Mark mode, it activates the
mark.  If point is between paragraphs (in a run of blank lines, or at a
boundary), the paragraph following point is surrounded by point and
mark.  If there are blank lines preceding the first line of the
paragraph, one of these blank lines is included in the region.

@vindex paragraph-start
@vindex paragraph-separate
  The precise definition of a paragraph boundary is controlled by the
variables @code{paragraph-separate} and @code{paragraph-start}.  The
value of @code{paragraph-start} is a regexp that should match any line
that either starts or separates paragraphs.  The value of
@code{paragraph-separate} is another regexp that should match only lines
that separate paragraphs without being part of any paragraph.  Lines
that start a new paragraph and are contained in it must match only
@code{paragraph-start}, not @code{paragraph-separate}.  For example,
normally @code{paragraph-start} is @code{"^[ @t{\}t@t{\}n@t{\}f]"} and
@code{paragraph-separate} is @code{"^[ @t{\}t@t{\}f]*$"}.@refill

  Normally it is desirable for page boundaries to separate paragraphs.
The default values of these variables recognize the usual separator for
pages.

@node Pages
@section Pages

@cindex pages
@cindex formfeed
  Files are often thought of as divided into @dfn{pages} by the
@dfn{formfeed} character (ASCII control-L, octal code 014).  When you
print hardcopy for a file, this character forces a page break; thus,
each page of the file goes on a separate page on paper.  Most Emacs
commands treat the page-separator character just like any other
character: you can insert it with @kbd{C-q C-l}, and delete it with
@key{DEL}.  Thus, you are free to paginate your file or not.  However,
since pages are often meaningful divisions of the file, Emacs provides
commands to move over them and operate on them.

@c WideCommands
@table @kbd
@item C-x [
Move point to previous page boundary (@code{backward-page}).
@item C-x ]
Move point to next page boundary (@code{forward-page}).
@item C-x C-p
Put point and mark around this page (or another page) (@code{mark-page}).
@item C-x l
Count the lines in this page (@code{count-lines-page}).
@end table

@kindex C-x [
@kindex C-x ]
@findex forward-page
@findex backward-page
  The @kbd{C-x [} (@code{backward-page}) command moves point to immediately
after the previous page delimiter.  If point is already right after a page
delimiter, it skips that one and stops at the previous one.  A numeric
argument serves as a repeat count.  The @kbd{C-x ]} (@code{forward-page})
command moves forward past the next page delimiter.

@kindex C-x C-p
@findex mark-page
  The @kbd{C-x C-p} command (@code{mark-page}) puts point at the
beginning of the current page and the mark at the end.  The page
delimiter at the end is included (the mark follows it).  The page
delimiter at the front is excluded (point follows it).  @kbd{C-x C-p
C-w} is a handy way to kill a page to move it elsewhere.  If you move to
another page delimiter with @kbd{C-x [} and @kbd{C-x ]}, then yank the
killed page, all the pages will be properly delimited once again.  The
reason @kbd{C-x C-p} includes only the following page delimiter in the
region is to ensure that.

  A numeric argument to @kbd{C-x C-p} is used to specify which page to go
to, relative to the current one.  Zero means the current page.  One means
the next page, and @minus{}1 means the previous one.

@kindex C-x l
@findex count-lines-page
  The @kbd{C-x l} command (@code{count-lines-page}) is good for deciding
where to break a page in two.  It prints in the echo area the total number
of lines in the current page, and then divides it up into those preceding
the current line and those following, as in

@example
Page has 96 (72+25) lines
@end example

@noindent
  Notice that the sum is off by one; this is correct if point is not at the
beginning of a line.

@vindex page-delimiter
  The variable @code{page-delimiter} controls where pages begin.  Its
value is a regexp that matches the beginning of a line that separates
pages.  The normal value of this variable is @code{"^@t{\}f"}, which
matches a formfeed character at the beginning of a line.

@node Filling
@section Filling Text
@cindex filling text

  @dfn{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.

@menu
* Auto Fill::	  Auto Fill mode breaks long lines automatically.
* Fill Commands:: Commands to refill paragraphs and center lines.
* Fill Prefix::	  Filling when every line is indented or in a comment, etc.
@end menu

@node Auto Fill
@subsection Auto Fill Mode
@cindex Auto Fill mode
@cindex mode, Auto Fill

  @dfn{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 @key{SPC} or @key{RET}.

@table @kbd
@item M-x auto-fill-mode
Enable or disable Auto Fill mode.
@item @key{SPC}
@itemx @key{RET}
In Auto Fill mode, break lines when appropriate.
@end table

@findex auto-fill-mode
  @kbd{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
@samp{Fill} in the mode line, inside the parentheses.  Auto Fill mode is
a minor mode which is enabled or disabled for each buffer individually.
@xref{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 @key{SPC} or @key{RET}.  If you wish to insert a space
or newline without permitting line-breaking, type @kbd{C-q @key{SPC}} or
@kbd{C-q @key{LFD}} (recall that a newline is really a linefeed).  Also,
@kbd{C-o} inserts a newline without line breaking.

  Auto Fill mode works well with Lisp mode, because when it makes a new
line in Lisp mode it indents that line with @key{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 @code{comment-multi-line} controls the
choice (@pxref{Comments}).

  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.
@ifinfo
@xref{Fill Commands}.
@end ifinfo

  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.
@xref{Init File}.

@node Fill Commands
@subsection Explicit Fill Commands

@table @kbd
@item M-q
Fill current paragraph (@code{fill-paragraph}).
@item C-x f
Set the fill column (@code{set-fill-column}).
@item M-x fill-region
Fill each paragraph in the region (@code{fill-region}).
@item M-x fill-region-as-paragraph.
Fill the region, considering it as one paragraph.
@item M-s
Center a line.
@end table

@kindex M-q
@findex fill-paragraph
  To refill a paragraph, use the command @kbd{M-q}
(@code{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.

@findex fill-region
  To refill many paragraphs, use @kbd{M-x fill-region}, which
divides the region into paragraphs and fills each of them.

  @kbd{M-q} and @code{fill-region} use the same criteria as @kbd{M-h}
for finding paragraph boundaries (@pxref{Paragraphs}).  For more
control, you can use @kbd{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.@refill

@cindex justification
  A numeric argument to @kbd{M-q} causes it to @dfn{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 @kbd{M-q} with no argument.  (Likewise for
@code{fill-region}.)

@vindex adaptive-fill-mode
@findex fill-region-as-paragraph
  When @code{adaptive-fill-mode} is non-@code{nil} (which is normally
the case), if you use @code{fill-region-as-paragraph} on an indented
paragraph and you don't have a fill prefix, it uses the indentation of
the second line of the paragraph as the fill prefix.  The effect of
adaptive filling is not noticeable in Text mode, because an indented
line counts as a paragraph starter and thus each line of an indented
paragraph is considered a paragraph of its own.  But you do notice the
effect in Indented Text mode and some other major modes.

@kindex M-s @r{(Text mode)}
@cindex centering
@findex center-line
  The command @kbd{M-s} (@code{center-line}) centers the current line
within the current fill column.  With an argument @var{n}, it centers
@var{n} lines individually and moves past them.

@vindex fill-column
@kindex C-x f
@findex set-fill-column
  The maximum line width for filling is in the variable
@code{fill-column}.  Altering the value of @code{fill-column} makes it
local to the current buffer; until that time, the default value is in
effect.  The default is initially 70.  @xref{Locals}.  The easiest way
to set @code{fill-column} is to use the command @kbd{C-x f}
(@code{set-fill-column}).  With no argument, it sets @code{fill-column}
to the current horizontal position of point.  With a numeric argument,
it uses that as the new fill column.

  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.

@vindex sentence-end-double-space
  If the variable @code{sentence-end-double-space} is @code{nil}, the
fill commands expect and leave just one space at the end of a sentence.
Ordinarily this variable is @code{t}, so the fill commands insist on
two spaces for the end of a sentence, as explained above.  @xref{Sentences}.

@node Fill Prefix
@subsection The Fill Prefix

@cindex 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), use the
@dfn{fill prefix} feature.  The fill prefix is a string which Emacs expects
every line to start with, and which is not included in filling.

@table @kbd
@item C-x .
Set the fill prefix (@code{set-fill-prefix}).
@item M-q
Fill a paragraph using current fill prefix (@code{fill-paragraph}).
@item M-x fill-individual-paragraphs
Fill the region, considering each change of indentation as starting a
new paragraph.
@item M-x fill-nonuniform-paragraphs
Fill the region, considering only paragraph-separator lines as starting
a new paragraph.
@end table

@kindex C-x .
@findex set-fill-prefix
  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
@w{@kbd{C-x .}}@: (@code{set-fill-prefix}).  That's a period after the
@kbd{C-x}.  To turn off the fill prefix, specify an empty prefix: type
@w{@kbd{C-x .}}@: with point at the beginning of a line.@refill

  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 @kbd{C-o} command inserts the fill prefix on
new lines it creates, when you use it at the beginning of a line
(@pxref{Blank Lines}).  Conversely, the command @kbd{M-^} deletes the
prefix (if it occurs) after the newline that it deletes
(@pxref{Indentation}).

  For example, if @code{fill-column} is 40 and you set the fill prefix
to @samp{;; }, then @kbd{M-q} in the following text

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

@noindent
produces this:

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

  Lines that do not start with the fill prefix are considered to start
paragraphs, both in @kbd{M-q} and the paragraph commands; this is 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.

@findex fill-individual-paragraphs
  You can use @kbd{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.

@findex fill-nonuniform-paragraphs
  @kbd{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 @code{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.

@vindex fill-prefix
  The fill prefix is stored in the variable @code{fill-prefix}.  Its value
is a string, or @code{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.  @xref{Locals}.

@node Case
@section Case Conversion Commands
@cindex case conversion

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

@c WideCommands
@table @kbd
@item M-l
Convert following word to lower case (@code{downcase-word}).
@item M-u
Convert following word to upper case (@code{upcase-word}).
@item M-c
Capitalize the following word (@code{capitalize-word}).
@item C-x C-l
Convert region to lower case (@code{downcase-region}).
@item C-x C-u
Convert region to upper case (@code{upcase-region}).
@end table

@kindex M-l
@kindex M-u
@kindex M-c
@cindex words, case conversion
@cindex converting text to upper or lower case
@cindex capitalizing words
@findex downcase-word
@findex upcase-word
@findex capitalize-word
  The word conversion commands are the most useful.  @kbd{M-l}
(@code{downcase-word}) converts the word after point to lower case, moving
past it.  Thus, repeating @kbd{M-l} converts successive words.
@kbd{M-u} (@code{upcase-word}) converts to all capitals instead, while
@kbd{M-c} (@code{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 @kbd{M-l}, @kbd{M-u} or
@kbd{M-c} on each word as appropriate, occasionally using @kbd{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 @kbd{M-d} (@code{kill-word}) does.  With a negative argument,
case conversion applies only to the part of the word before point.

@kindex C-x C-l
@kindex C-x C-u
@findex downcase-region
@findex upcase-region
  The other case conversion commands are @kbd{C-x C-u}
(@code{upcase-region}) and @kbd{C-x C-l} (@code{downcase-region}), which
convert everything between point and mark to the specified case.  Point and
mark do not move.

  The region case conversion commands @code{upcase-region} and
@code{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.
@xref{Disabling}.

@node Text Mode
@section Text Mode
@cindex Text mode
@cindex mode, Text
@findex text-mode

  When you edit files of text in a human language, it's more convenient
to use Text mode rather than Fundamental mode.  Invoke @kbd{M-x
text-mode} to enter Text mode.  In Text mode, @key{TAB} runs the
function @code{tab-to-tab-stop}, which allows you to use arbitrary tab
stops set with @kbd{M-x edit-tab-stops} (@pxref{Tab Stops}).  Features
concerned with comments in programs are turned off in Text mode except
when explicitly invoked.  The syntax table is changed so that periods
are not considered part of a word, while apostrophes, backspaces and
underlines are part of words.

@cindex Indented Text mode
@cindex mode, Indented Text
@findex indented-text-mode
@kindex TAB @r{(Indented Text mode)}
  A similar variant mode is Indented Text mode, intended for editing
text in which most lines are indented.  This mode defines @key{TAB} to
run @code{indent-relative} (@pxref{Indentation}), and makes Auto Fill
indent the lines it creates.  The result is that normally a line made by
Auto Filling, or by @key{LFD}, is indented just like the previous line.
In Indented Text mode, only blank lines separate paragraphs---indented
lines continue the current paragraph.  Use @kbd{M-x indented-text-mode}
to select this mode.

@kindex M-TAB @r{(Text mode)}
  Text mode, and all the modes based on it, define @kbd{M-@key{TAB}} as
the command @code{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.  @xref{Spelling}.

@vindex text-mode-hook
  Entering Text mode or Indented Text mode runs the hook
@code{text-mode-hook}.  Other major modes related to Text mode also run
this hook, followed by hooks of their own; this includes Nroff mode,
@TeX{} mode, Outline mode and Mail mode.  Hook functions on
@code{text-mode-hook} can look at the value of @code{major-mode} to see
which of these modes is actually being entered.  @xref{Hooks}.

@menu
  Emacs provides two other modes for editing text that is to be passed
through a text formatter to produce fancy formatted printed output.

* Nroff Mode::	  The major mode for editing input to the formatter nroff.
* TeX Mode::	  The major modes 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.

* Outline Mode::  The major mode for editing outlines.
@end menu

@node Outline Mode
@section Outline Mode
@cindex Outline mode
@cindex mode, Outline
@cindex selective display
@cindex invisible lines

@findex outline-mode
@findex outline-minor-mode
@vindex outline-minor-mode-prefix
  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 @kbd{M-x
outline-mode} to switch to Outline mode as the major mode of the current
buffer.  Type @kbd{M-x outline-minor-mode} to enable Outline mode as a
minor mode in the current buffer.  Outline minor mode provides the same
commands as the major mode, Outline mode, but you can use it in
conjunction with other major modes.

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

  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).

  All editing commands treat the text of the invisible line as part of the
previous visible line.  For example, @kbd{C-n} moves onto the next visible
line.  Killing an entire visible line, including its terminating newline,
really kills all the following invisible lines along with it; yanking it
all back yanks the invisible lines and they remain invisible.

@vindex outline-mode-hook
  Entering Outline mode runs the hook @code{text-mode-hook} followed by
the hook @code{outline-mode-hook} (@pxref{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.
@end menu

@node Outline Format
@subsection Format of Outlines

@cindex heading lines (Outline mode)
@cindex body lines (Outline mode)
  Outline mode assumes that the lines in the buffer are of two types:
@dfn{heading lines} and @dfn{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:

@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.
@end example

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

@vindex outline-regexp
  You can customize the criterion for distinguishing heading lines
by setting the variable @code{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 @samp{@@chapter}, @samp{@@section}
and @samp{@@subsection} to divide the document into chapters and
sections, you could make those lines count as heading lines by
setting @code{outline-regexp} to @samp{"@@chap\\|@@\\(sub\\)*section"}.
Note the trick: the two words @samp{chapter} and @samp{section} are equally
long, but by defining the regexp to match only @samp{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 @samp{@@chap}.

@vindex outline-level
  It is possible to change the rule for calculating the level of a
heading line by setting the variable @code{outline-level}.  The value of
@code{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.

  Outline mode makes a line invisible by changing the newline before it
into an ASCII control-M (code 015).  Most editing commands that work on
lines treat an invisible line as part of the previous line because,
strictly speaking, it @emph{is} part of that line, since there is no longer a
newline in between.  When you save the file in Outline mode, control-M
characters are saved as newlines, so the invisible lines become ordinary
lines in the file.  But saving does not change the visibility status of a
line inside Emacs.

@node Outline Motion
@subsection Outline Motion Commands

  There are some special motion commands in Outline mode that move
backward and forward to heading lines.

@table @kbd
@item C-c C-n
Move point to the next visible heading line
(@code{outline-next-visible-heading}).
@item C-c C-p
Move point to the previous visible heading line
(@code{outline-previous-visible-heading}).
@item C-c C-f
Move point to the next visible heading line at the same level
as the one point is on (@code{outline-forward-same-level}).
@item C-c C-b
Move point to the previous visible heading line at the same level
(@code{outline-backward-same-level}).
@item C-c C-u
Move point up to a lower-level (more inclusive) visible heading line
(@code{outline-up-heading}).
@end table

@findex outline-next-visible-heading
@findex outline-previous-visible-heading
@kindex C-c C-n @r{(Outline mode)}
@kindex C-c C-p @r{(Outline mode)}
  @kbd{C-c C-n} (@code{next-visible-heading}) moves down to the next
heading line.  @kbd{C-c C-p} (@code{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.@refill

@findex outline-up-heading
@findex outline-forward-same-level
@findex outline-backward-same-level
@kindex C-c C-f @r{(Outline mode)}
@kindex C-c C-b @r{(Outline mode)}
@kindex C-c C-u @r{(Outline mode)}
  More powerful motion commands understand the level structure of headings.
@kbd{C-c C-f} (@code{outline-forward-same-level}) and
@kbd{C-c C-b} (@code{outline-backward-same-level}) move from one
heading line to another visible heading at the same depth in
the outline.  @kbd{C-c C-u} (@code{outline-up-heading}) moves
backward to another heading that is less deeply nested.

@node Outline Visibility
@subsection Outline Visibility Commands

  The other special commands of outline mode are used to make lines visible
or invisible.  Their names all start with @code{hide} or @code{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.

@table @kbd
@item C-c C-t
Make all body lines in the buffer invisible (@code{hide-body}).
@item C-c C-a
Make all lines in the buffer visible (@code{show-all}).
@item C-c C-d
Make everything under this heading invisible, not including this
heading itself@* (@code{hide-subtree}).
@item C-c C-s
Make everything under this heading visible, including body,
subheadings, and their bodies (@code{show-subtree}).
@item C-c C-l
Make the body of this heading line, and of all its subheadings,
invisible (@code{hide-leaves}).
@item C-c C-k
Make all subheadings of this heading line, at all levels, visible
(@code{show-branches}). 
@item C-c C-i
Make immediate subheadings (one level down) of this heading line
visible (@code{show-children}).
@item C-c C-c
Make this heading line's body invisible (@code{hide-entry}).
@item C-c C-e
Make this heading line's body visible (@code{show-entry}).
@item C-c C-q
Hide everything except the top @var{n} levels of heading lines
(@code{hide-sublevels}).
@item 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
(@code{hide-other}).
@end table

@findex hide-entry
@findex show-entry
@kindex C-c C-c @r{(Outline mode)}
@kindex C-c C-e @r{(Outline mode)}
  Two commands that are exact opposites are @kbd{C-c C-c}
(@code{hide-entry}) and @kbd{C-c C-e} (@code{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.

@findex hide-subtree
@findex show-subtree
@kindex C-c C-s @r{(Outline mode)}
@kindex C-c C-d @r{(Outline mode)}
@cindex subtree (Outline mode)
  Two more powerful opposites are @kbd{C-c C-d} (@code{hide-subtree}) and
@kbd{C-c C-s} (@code{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
@dfn{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.@refill

@findex hide-leaves
@findex show-branches
@kindex C-c C-l @r{(Outline mode)}
@kindex C-c C-k @r{(Outline mode)}
  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 @kbd{C-c C-l}
(@code{hide-leaves}) and @kbd{C-c C-k} (@code{show-branches}).

@kindex C-c C-i @r{(Outline mode)}
@findex show-children
  A little weaker than @code{show-branches} is @kbd{C-c C-i}
(@code{show-children}).  It makes just the direct subheadings
visible---those one level down.  Deeper subheadings remain invisible, if
they were invisible.@refill

@findex hide-body
@findex show-all
@kindex C-c C-t @r{(Outline mode)}
@kindex C-c C-a @r{(Outline mode)}
  Two commands have a blanket effect on the whole file.  @kbd{C-c C-t}
(@code{hide-body}) makes all body lines invisible, so that you see just
the outline structure.  @kbd{C-c C-a} (@code{show-all}) makes all lines
visible.  These commands can be thought of as a pair of opposites even
though @kbd{C-c C-a} applies to more than just body lines.

@findex hide-sublevels
@kindex C-c C-q @r{(Outline mode)}
  The command @kbd{C-c C-q} (@code{hide-sublevels}) hides all but the
top level headings.  With a numeric argument @var{n}, it hides everything
except the top @var{n} levels of heading lines.

@findex hide-other
@kindex C-c C-o @r{(Outline mode)}
  The command @kbd{C-c C-o} (@code{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 @code{selective-display-ellipses} to @code{nil}.  Then there is
no visible indication of the presence of invisible lines.

@node TeX Mode
@section @TeX{} Mode
@cindex @TeX{} mode
@cindex La@TeX{} mode
@cindex Sli@TeX{} mode
@findex tex-mode
@findex plain-tex-mode
@findex latex-mode
@findex slitex-mode

  @TeX{} is a powerful text formatter written by Donald Knuth; it is also
free, like GNU Emacs.  La@TeX{} is a simplified input format for @TeX{},
implemented by @TeX{} macros; it comes with @TeX{}.  Sli@TeX{} is a special
form of La@TeX{}.@refill

  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.

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

  When @kbd{M-x tex-mode} does not guess right, you can use the commands
@kbd{M-x plain-tex-mode}, @kbd{M-x latex-mode}, and @kbd{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.
* Getting: TeX Distrib.   Getting the latest Unix TeX distribution.
@end menu

@node TeX Editing
@subsection @TeX{} Editing Commands

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

@table @kbd
@item "
Insert, according to context, either @samp{``} or @samp{"} or
@samp{''} (@code{tex-insert-quote}).
@item @key{LFD}
Insert a paragraph break (two newlines) and check the previous
paragraph for unbalanced braces or dollar signs
(@code{tex-terminate-paragraph}).
@item M-x validate-tex-region
Check each paragraph in the region for unbalanced braces or dollar signs.
@item C-c @{
Insert @samp{@{@}} and position point between them (@code{tex-insert-braces}).
@item C-c @}
Move forward past the next unmatched close brace (@code{up-list}).
@end table

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

  If you need the character @samp{"} itself in unusual contexts, use
@kbd{C-q} to insert it.  Also, @kbd{"} with a numeric argument always
inserts that number of @samp{"} characters.

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

@findex tex-insert-braces
@kindex C-c @{ @r{(@TeX{} mode)}
@findex up-list
@kindex C-c @} @r{(@TeX{} mode)}
  @TeX{} uses braces as delimiters that must match.  Some users prefer
to keep braces balanced at all times, rather than inserting them
singly.  Use @kbd{C-c @{} (@code{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 @kbd{C-c @}}
(@code{up-list}) to move forward past the close brace.

@findex validate-tex-region
@findex tex-terminate-paragraph
@kindex LFD @r{(@TeX{} mode)}
  There are two commands for checking the matching of braces.  @key{LFD}
(@code{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.  @kbd{M-x validate-tex-region}
checks a region, paragraph by paragraph.  When it finds a paragraph that
contains a mismatch, it displays point at the beginning of the paragraph
for a few seconds and sets the mark at that spot.  Scanning continues
until the whole buffer has been checked or until you type another key.
Afterward, you can use the mark ring to find the last several paragraphs
that had mismatches (@pxref{Mark Ring}).

  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.

@node LaTeX Editing
@subsection La@TeX{} Editing Commands

  La@TeX{} mode, and its variant, Sli@TeX{} mode, provide a few extra
features not applicable to plain @TeX{}.

@table @kbd
@item C-c C-o
Insert @samp{\begin} and @samp{\end} for La@TeX{} block and position
point on a line between them. (@code{tex-latex-block}).
@item C-c C-e
Close the last unended block for La@TeX{} (@code{tex-close-latex-block}).
@end table

@findex tex-latex-block
@kindex C-c C-o @r{(La@TeX{} mode)}
@vindex latex-block-names
  In La@TeX{} input, @samp{\begin} and @samp{\end} commands are used to
group blocks of text.  To insert a @samp{\begin} and a matching
@samp{\end} (on a new line following the @samp{\begin}), use @kbd{C-c
C-o} (@code{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 @code{latex-block-names}.  For example, here's
how to add @samp{theorem}, @samp{corollary}, and @samp{proof}:

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

@findex tex-close-latex-block
@kindex C-c C-e @r{(La@TeX{} mode)}
  In La@TeX{} input, @samp{\begin} and @samp{\end} commands must
balance.  You can use @kbd{C-c C-e} (@code{tex-close-latex-block}) to
insert automatically a matching @samp{\end} to match the last unmatched
@samp{\begin}.  It indents the @samp{\end} to match the corresponding
@samp{\begin}.  It inserts a newline after @samp{\end} if point is at
the beginning of a line.

@node TeX Print
@subsection @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.

@table @kbd
@item C-c C-r
Invoke @TeX{} on the current region, together with the buffer's header
(@code{tex-region}).
@item C-c C-b
Invoke @TeX{} on the entire current buffer (@code{tex-buffer}).
@item C-c TAB
Invoke Bib@TeX{} on the current file (@code{tex-bibtex-file}).
@item C-c C-f
Invoke @TeX{} on the current file (@code{tex-file}).
@item C-c C-l
Recenter the window showing output from the inferior @TeX{} so that
the last line can be seen (@code{tex-recenter-output-buffer}).
@item C-c C-k
Kill the @TeX{} subprocess (@code{tex-kill-job}).
@item C-c C-p
Print the output from the last @kbd{C-c C-r}, @kbd{C-c C-b}, or @kbd{C-c
C-f} command (@code{tex-print}).
@item C-c C-v
Preview the output from the last @kbd{C-c C-r}, @kbd{C-c C-b}, or @kbd{C-c
C-f} command (@code{tex-view}).
@item C-c C-q
Show the printer queue (@code{tex-show-print-queue}).
@end table

@findex tex-buffer
@kindex C-c C-b @r{(@TeX{} mode)}
@findex tex-print
@kindex C-c C-p @r{(@TeX{} mode)}
@findex tex-view
@kindex C-c C-v @r{(@TeX{} mode)}
@findex tex-show-print-queue
@kindex C-c C-q @r{(@TeX{} mode)}
  You can pass the current buffer through an inferior @TeX{} by means of
@kbd{C-c C-b} (@code{tex-buffer}).  The formatted output appears in a
temporary file; to print it, type @kbd{C-c C-p} (@code{tex-print}).
Afterward, you can use @kbd{C-c C-q} (@code{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 @kbd{C-c C-v} (@code{tex-view}).

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

@vindex tex-run-command
@vindex latex-run-command
@vindex slitex-run-command
@vindex tex-dvi-print-command
@vindex tex-dvi-view-command
@vindex tex-show-queue-command
  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 @code{tex-run-command},
@code{latex-run-command}, @code{slitex-run-command},
@code{tex-dvi-print-command}, @code{tex-dvi-view-command}, and
@code{tex-show-queue-command}.  You @emph{must} set the value of
@code{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, @samp{latex @var{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 @samp{*} in the command string.  For example,

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

@findex tex-kill-job
@kindex C-c C-k @r{(@TeX{} mode)}
@findex tex-recenter-output-buffer
@kindex C-c C-l @r{(@TeX{} mode)}
  The terminal output from @TeX{}, including any error messages, appears
in a buffer called @samp{*tex-shell*}.  If @TeX{} gets an error, you can
switch to this buffer and feed it input (this works as in Shell mode;
@pxref{Interactive Shell}).  Without switching to this buffer you can
scroll it so that its last line is visible by typing @kbd{C-c
C-l}.

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

@findex tex-region
@kindex C-c C-r @r{(@TeX{} mode)}
  You can also pass an arbitrary region through an inferior @TeX{} by typing
@kbd{C-c C-r} (@code{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, @kbd{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 @dfn{header}.

@cindex header (@TeX{} mode)
  To indicate the bounds of the header in Plain @TeX{} mode, you insert two
special strings in the file.  Insert @samp{%**start of header} before the
header, and @samp{%**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 @samp{%**start of header} does not appear within the first 100 lines of
the buffer, @kbd{C-c C-r} assumes that there is no header.

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

@findex tex-file
@kindex C-c C-f @r{(@TeX{} mode)}
  The commands (@code{tex-buffer}) and (@code{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, use @kbd{C-c C-f}
(@code{tex-file}) which runs @TeX{} on the current buffer's file, in that
file's directory.  Before @TeX{} runs, you will be asked about saving
any modified buffers.  Generally, you need to use (@code{tex-file})
twice to get cross-references correct.

@findex tex-bibtex-file
@kindex C-c TAB @r{(@TeX{} mode)}
@vindex tex-bibtex-command
  For La@TeX{} files, you can use Bib@TeX{} to process the auxiliary
file for the current buffer's file.  Bib@TeX{} looks up bibliographic
citations in a data base and prepares the cited references for the
bibliography section.  The command @kbd{C-c TAB}
(@code{tex-bibtex-file}) runs the shell command
(@code{tex-bibtex-command}) to produce a @samp{.bbl} file for the
current buffer's file.  Generally, you need to do @kbd{C-c C-f}
(@code{tex-file}) once to generate the @samp{.aux} file, then do
@kbd{C-c TAB} (@code{tex-bibtex-file}), and then repeat @kbd{C-c C-f}
(@code{tex-file}) twice more to get the cross-references correct.

@vindex tex-shell-hook
@vindex tex-mode-hook
@vindex latex-mode-hook
@vindex slitex-mode-hook
@vindex plain-tex-mode-hook
  Entering any kind of @TeX{} mode runs the hooks @code{text-mode-hook}
and @code{tex-mode-hook}.  Then it runs either
@code{plain-tex-mode-hook} or @code{latex-mode-hook}, whichever is
appropriate.  For Sli@TeX{} files, it calls @code{slitex-mode-hook}.
Starting the @TeX{} shell runs the hook @code{tex-shell-hook}.
@xref{Hooks}.

@node TeX Distrib
@subsection Unix @TeX{} Distribution

@c !!! Here is information about obtaining TeX.  Update it whenever.
@c     Last updated by rms in July 1994

@TeX{} for Unix systems can be obtained from the University of Washington
for a distribution fee.

To order a full distribution, specify whether you prefer 1/4 inch QIC-24
or 4mm DAT tape (9-track reel-to-reel is no longer available) and send
$210.00 for a (tar or cpio) cartridge, payable to the University of
Washington to:

@display
@group
Pierre MacKay
Department of Classics
Denny Hall, Mail Stop DH-10
University of Washington
Seattle, Washington 98195
@end group
@end display

@noindent
Purchase orders are acceptable, but there is an extra charge of
$10.00, to pay for processing charges.

@noindent
For overseas orders please add $20.00 to the base cost for shipment via
air parcel post, or $30.00 for shipment via courier.

  The normal distribution is a tar tape, blocked 20, 1600 bpi, on an
industry standard 2400 foot half-inch reel.  The physical format for the
1/4 inch streamer cartridges is QIC-24.  System V tapes can be written
in cpio format, blocked 5120 bytes, with ASCII headers.

@node Nroff Mode
@section Nroff Mode

@cindex nroff
@findex nroff-mode
  Nroff mode is a mode like Text mode but modified to handle nroff commands
present in the text.  Invoke @kbd{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 @samp{.bp} commands.  Comments
start with backslash-doublequote.  Also, three special commands are
provided that are not in Text mode:

@findex forward-text-line
@findex backward-text-line
@findex count-text-lines
@kindex M-n @r{(Nroff mode)}
@kindex M-p @r{(Nroff mode)}
@kindex M-? @r{(Nroff mode)}
@table @kbd
@item M-n
Move to the beginning of the next line that isn't an nroff command
(@code{forward-text-line}).  An argument is a repeat count.
@item M-p
Like @kbd{M-n} but move up (@code{backward-text-line}).
@item M-?
Prints in the echo area the number of text lines (lines that are not
nroff commands) in the region (@code{count-text-lines}).
@end table

@findex electric-nroff-mode
  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 @kbd{M-x
electric-nroff-mode} (@pxref{Minor Modes}).  When the mode is on, each
time you use @key{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 @kbd{.@: ( b @key{RET}},
this inserts the matching command @samp{.)b} on a new line following
point.

  If you use Outline minor mode with Nroff mode (@pxref{Outline Mode}),
heading lines are lines of the form @samp{.H} followed by a number (the
header level).

@vindex nroff-mode-hook
  Entering Nroff mode runs the hook @code{text-mode-hook}, followed by
the hook @code{nroff-mode-hook} (@pxref{Hooks}).