The term 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 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. Outline mode provides special commands for operating on text with an outline structure. See section Outline Mode.
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 (see section TeX Mode). For input to nroff, use Nroff mode.
Instead of using a text formatter, you can edit formatted text in WYSIWYG style ("what you see is what you get"), with Enriched mode. Then the formatting appears on the screen in Emacs while you edit. See section Editing Formatted Text.
Emacs has commands for moving over or operating on words. By convention, the keys for them are all Meta characters.
forward-word).
backward-word).
kill-word).
backward-kill-word).
mark-word).
transpose-words).
Notice how these keys form a series that parallels the character-based C-f, C-b, C-d, DEL and C-t. M-@ is cognate to C-@, which is an alias for C-SPC.
The commands M-f (forward-word) and M-b
(backward-word) move forward and backward over words. These
Meta characters are thus analogous to the corresponding control
characters, C-f and C-b, which move over single characters
in the text. The analogy extends to numeric arguments, which serve as
repeat counts. M-f with a negative argument moves backward, and
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.
M-d (kill-word) kills the word after point. To be
precise, it kills everything from point to the place M-f would
move to. Thus, if point is in the middle of a word, 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 M-f to get
the end, and kill the word backwards with M-DEL.)
M-d takes arguments just like M-f.
M-DEL (backward-kill-word) kills the word before
point. It kills everything from point back to where M-b would
move to. If point is after the space in `FOO, BAR', then
`FOO, ' is killed. (If you wish to kill just `FOO', and
not the comma and the space, use M-b M-d instead of
M-DEL.)
M-t (transpose-words) exchanges the word before or
containing point with the following word. The delimiter characters between
the words do not move. For example, `FOO, BAR' transposes into
`BAR, FOO' rather than `BAR FOO,'. See section Transposing Text, for
more on transposition and on arguments to transposition commands.
To operate on the next 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 M-@ (mark-word)
which does not move point, but sets the mark where M-f would move
to. 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. See section The Syntax Table.
The Emacs commands for manipulating sentences and paragraphs are mostly on Meta keys, so as to be like the word-handling commands.
backward-sentence).
forward-sentence).
kill-sentence).
backward-kill-sentence).
The commands M-a and M-e (backward-sentence and
forward-sentence) move to the beginning and end of the current
sentence, respectively. They were chosen to resemble C-a and
C-e, which move to the beginning and end of a line. Unlike them,
M-a and 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.
Just as C-a and C-e have a kill command, C-k, to go
with them, so M-a and M-e have a corresponding kill command
M-k (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, C-x DEL
(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.
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 `.', `?' or `!' followed by the end of a line or two spaces, with any number of `)', `]', `'', or `"' characters allowed in between. A sentence also begins or ends wherever a paragraph begins or ends.
The variable 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
"[.?!][]\"')]*\\($\\|\t\\| \\)[ \t\n]*"
This example is explained in the section on regexps. See section Syntax of Regular Expressions.
If you want to use just one space between sentences, you should
set sentence-end to this value:
"[.?!][]\"')]*\\($\\|\t\\| \\)[ \t\n]*"
You should also set the variable sentence-end-double-space to
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.
The Emacs commands for manipulating paragraphs are also Meta keys.
backward-paragraph).
forward-paragraph).
mark-paragraph).
M-{ moves to the beginning of the current or previous paragraph, while 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. In Fundamental mode, but not in Text mode, an indented line also starts a new paragraph. (If a paragraph is preceded by a blank line, these commands treat that blank line as the beginning of the paragraph.)
In major modes for programs, 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. See section Filling Text.
When you wish to operate on a paragraph, you can use the command
M-h (mark-paragraph) to set the region around it. Thus,
for example, M-h C-w kills the paragraph around or after point.
The 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.
The precise definition of a paragraph boundary is controlled by the
variables paragraph-separate and paragraph-start. The
value of paragraph-start is a regexp that should match any line
that either starts or separates paragraphs. The value of
paragraph-separate is another regexp that should match only lines
that separate paragraphs without being part of any paragraph (for
example, blank lines). Lines that start a new paragraph and are
contained in it must match only paragraph-start, not
paragraph-separate. For example, in Fundamental mode,
paragraph-start is "[ \t\n\f]" and
paragraph-separate is "[ \t\f]*$".
Normally it is desirable for page boundaries to separate paragraphs. The default values of these variables recognize the usual separator for pages.
Files are often thought of as divided into pages by the 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 C-q C-l, and delete it with 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.
backward-page).
forward-page).
mark-page).
count-lines-page).
The C-x [ (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 C-x ] (forward-page)
command moves forward past the next page delimiter.
The C-x C-p command (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). 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 C-x [ and C-x ], then yank the
killed page, all the pages will be properly delimited once again. The
reason C-x C-p includes only the following page delimiter in the
region is to ensure that.
A numeric argument to 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 -1 means the previous one.
The C-x l command (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
Page has 96 (72+25) lines
Notice that the sum is off by one; this is correct if point is not at the beginning of a line.
The variable 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 "^\f", which
matches a formfeed character at the beginning of a line.
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 (see section Editing Formatted Text).
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 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. See section 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
(see section Manipulating 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.
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. See section The Init File, `~/.emacs'.
fill-paragraph).
set-fill-column).
fill-region).
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 (see section 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 section Justification in Formatted Text.
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. See section Local Variables. 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. See section Sentences.
If the variable colon-double-space is non-nil, the
fill commands put two spaces after a colon.
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 (see section Adaptive Filling).
set-fill-prefix).
fill-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 (see section Blank Lines). Conversely, the command M-^ deletes the prefix (if it occurs) after the newline that it deletes (see section 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. See section Local Variables.
The indentation text property provides another way to control
the amount of indentation paragraphs receive. See section Indentation in Formatted Text.
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:
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.
Emacs has commands for converting either a single word or any arbitrary range of text to upper case or to lower case.
downcase-word).
upcase-word).
capitalize-word).
downcase-region).
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.
See section Disabling Commands.
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. See section Adaptive Filling.
Text mode defines TAB to run indent-relative
(see section 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 (see section 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. See section Checking and Correcting 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. See section Hooks.
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' (see section Local Variables in Files).
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 (see section Hooks).
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.
Outline mode provides special motion commands that move backward and forward to heading lines.
outline-next-visible-heading).
outline-previous-visible-heading).
outline-forward-same-level).
outline-backward-same-level).
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.
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.
hide-body).
show-all).
hide-subtree).
show-subtree).
hide-leaves).
show-branches).
show-children).
hide-entry).
show-entry).
hide-sublevels).
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.
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. See section 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.
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.
Here are the special commands provided in TeX mode for editing the text of the file.
tex-insert-quote).
tex-terminate-paragraph).
tex-insert-braces).
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 (See section Customizing 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 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 (see section The 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.
LaTeX mode, and its variant, SliTeX mode, provide a few extra features not applicable to plain TeX.
tex-latex-block).
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.
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.
tex-region).
tex-buffer).
tex-bibtex-file).
tex-file).
tex-recenter-output-buffer).
tex-kill-job).
tex-print).
tex-view).
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; see section Interactive Inferior 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.
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. See section Local Variables in Files.
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.
See section Hooks.
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:
forward-text-line). An argument is a repeat count.
backward-text-line).
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 (see section 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 (see section 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 (see section Hooks).
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 (see section Minor Modes). Typically it is used in conjunction with Text mode (see section 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. See section `Format Conversion' in the Emacs Lisp Reference Manual, 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.
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.
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. See section Auto Fill Mode.
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. See section Justification in Formatted Text.
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
facemenu-remove-props).
Remove All
facemenu-remove-all).
List Properties
list-text-properties-at).
Display Faces
Display Colors
The Faces submenu lists various Emacs faces including bold,
italic, and underline. Selecting one of these adds the
chosen face to the region. See section Using Multiple Typefaces. You can also specify a face
with these keyboard commands:
default face
(facemenu-set-default).
bold face
(facemenu-set-bold).
italic face
(facemenu-set-italic).
bold-italic face
(facemenu-set-bold-italic).
underline face
(facemenu-set-underline).
facemenu-set-face).
If you use these commands with a prefix argument--or, in Transient Mark mode, if the region is not active--then these commands specify a face to use for your next self-inserting input. See section Transient Mark Mode. This applies to both the keyboard commands and the menu commands.
Enriched mode defines two additional faces: excerpt and
fixed. These correspond to codes used in the text/enriched file
format.
The excerpt face is intended for quotations. This face is the
same as italic unless you customize it (see section Customizing Faces).
The fixed face is meant to say, "Use a fixed-width font for this
part of the text." Emacs currently supports only fixed-width fonts;
therefore, the fixed annotation is not necessary now. However,
we plan to support variable width fonts in future Emacs versions, and
other systems that display text/enriched format may not use a
fixed-width font as the default. So if you specifically want a certain
part of the text to use a fixed-width font, you should specify the
fixed face for that part.
The fixed face is normally defined to use a different font from
the default. However, different systems have different fonts installed,
so you may need to customize this.
If your terminal cannot display different faces, you will not be able to see them, but you can still edit documents containing faces. You can even add faces and colors to documents. They will be visible when the file is viewed on a terminal that can display them.
You can specify foreground and background colors for portions of the text. There is a menu for specifying the foreground color and a menu for specifying the background color. Each color menu lists all the colors that you have used in Enriched mode in the current Emacs session.
If you specify a color with a prefix argument--or, in Transient Mark mode, if the region is not active--then it applies to your next self-inserting input. See section Transient Mark Mode. Otherwise, the command applies to the region.
Each color menu contains one additional item: `Other'. You can use this item to specify a color that is not listed in the menu; it reads the color name with the minibuffer. To display list of available colors and their names, use the `Display Colors' menu item in the Text Properties menu (see section Editing Format Information).
Any color that you specify in this way, or that is mentioned in a formatted text file that you read in, is added to both color menus for the duration of the Emacs session.
There are no key bindings for specifying colors, but you can do so with the extended commands M-x facemenu-set-foreground and M-x facemenu-set-background. Both of these commands read the name of the color with the minibuffer.
When editing formatted text, you can specify different amounts of indentation for the right or left margin of an entire paragraph or a part of a paragraph. The margins you specify automatically affect the Emacs fill commands (see section Filling Text) and line-breaking commands.
The Indentation submenu provides a convenient interface for specifying these properties. The submenu contains four items:
Indent More
increase-left-margin). In
Enriched mode, this command is also available on C-x TAB; if
you supply a numeric argument, that says how many columns to add to the
margin (a negative argument reduces the number of columns).
Indent Less
Indent Right More
Indent Right Less
You can use these commands repeatedly to increase or decrease the indentation.
The most common way to use these commands is to change the indentation of an entire paragraph. However, that is not the only use. You can change the margins at any point; the new values take effect at the end of the line (for right margins) or the beginning of the next line (for left margins).
This makes it possible to format paragraphs with hanging indents, which means that the first line is indented less than subsequent lines. To set up a hanging indent, increase the indentation of the region starting after the first word of the paragraph and running until the end of the paragraph.
Indenting the first line of a paragraph is easier. Set the margin for the whole paragraph where you want it to be for the body of the paragraph, then indent the first line by inserting extra spaces or tabs.
Sometimes, as a result of editing, the filling of a paragraph becomes
messed up--parts of the paragraph may extend past the left or right
margins. When this happens, use M-q (fill-paragraph) to
refill the paragraph.
The variable standard-indent specifies how many columns these
commands should add to or subtract from the indentation. The default
value is 4. The overall default right margin for Enriched mode is
controlled by the variable fill-column, as usual.
The fill prefix, if any, works in addition to the specified paragraph indentation: C-x . does not include the specified indentation's whitespace in the new value for the fill prefix, and the fill commands look for the fill prefix after the indentation on each line. See section The Fill Prefix.
When editing formatted text, you can specify various styles of justification for a paragraph. The style you specify automatically affects the Emacs fill commands.
The Justification submenu provides a convenient interface for specifying the style. The submenu contains five items:
Flush Left
Flush Right
Full
Center
None
In Enriched mode, you can also specify justification from the keyboard using the M-j prefix character:
set-justification-left).
set-justification-right).
set-justification-full).
set-justification-center).
set-justification-none).
Justification styles apply to entire paragraphs. All the justification-changing commands operate on the paragraph containing point, or, if the region is active, on all paragraphs which overlap the region.
The default justification style is specified by the variable
default-justification. Its value should be one of the symbols
left, right, full, center, or none.
The Other Properties menu lets you add or remove three other useful text
properties: read-only, invisible and intangible.
The intangible property disallows moving point within the text,
the invisible text property hides text from display, and the
read-only property disallows alteration of the text.
Each of these special properties has a menu item to add it to the region. The last menu item, `Remove Special', removes all of these special properties from the text in the region.
Currently, the invisible and intangible properties are
not saved in the text/enriched format. The read-only
property is saved, but it is not a standard part of the text/enriched
format, so other editors may not respect it.
Normally, Emacs knows when you are editing formatted text because it recognizes the special annotations used in the file that you visited. However, there are situations in which you must take special actions to convert file contents or turn on Enriched mode:
The command format-decode-buffer translates text in various
formats into Emacs's internal format. It asks you to specify the format
to translate from; however, normally you can type just RET, which
tells Emacs to guess the format.
If you wish to look at text/enriched file in its raw form, as a
sequence of characters rather than as formatted text, use the M-x
find-file-literally command. This visits a file, like
find-file, but does not do format conversion. It also inhibits
character code conversion (see section Coding Systems) and automatic
uncompression (see section Accessing Compressed Files). To disable format conversion
but allow character code conversion and/or automatic uncompression if
appropriate, use format-find-file with suitable arguments.