Amiga Format CD 7/Amiga Format AFCD07 (Dec 1996, Issue 91).iso/serious/shareware/programming/emacs-complete/fsf/emacs/info/emacs-9

GNU Info File | 1994-10-05 | 50KB | 898 lines

This is Info file ../info/emacs, produced by Makeinfo-1.54 from the
input file emacs.texi.
File: emacs,  Node: Auto Fill,  Next: Fill Commands,  Up: Filling
Auto Fill Mode
--------------
   "Auto Fill" mode is a minor mode in which lines are broken
automatically when they become too wide.  Breaking happens only when
you type a SPC or RET.
`M-x auto-fill-mode'
     Enable or disable Auto Fill mode.
`SPC'
`RET'
     In Auto Fill mode, break lines when appropriate.
   `M-x auto-fill-mode' turns Auto Fill mode on if it was off, or off
if it was on.  With a positive numeric argument it always turns Auto
Fill mode on, and with a negative argument always turns it off.  You can
see when Auto Fill mode is in effect by the presence of the word `Fill'
in the mode line, inside the parentheses.  Auto Fill mode is a minor
mode which is enabled or disabled for each buffer individually.  *Note
Minor Modes::.
   In Auto Fill mode, lines are broken automatically at spaces when
they get longer than the desired width.  Line breaking and
rearrangement takes place only when you type SPC or RET.  If you wish
to insert a space or newline without permitting line-breaking, type
`C-q SPC' or `C-q LFD' (recall that a newline is really a linefeed).
Also, `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 TAB.  If a line ending in a
comment gets too long, the text of the comment is split into two
comment lines.  Optionally new comment delimiters are inserted at the
end of the first line and the beginning of the second so that each line
is a separate comment; the variable `comment-multi-line' controls the
choice (*note Comments::.).
   Auto Fill mode does not refill entire paragraphs; it can break lines
but cannot merge lines.  So editing in the middle of a paragraph can
result in a paragraph that is not correctly filled.  The easiest way to
make the paragraph properly filled again is usually with the explicit
fill commands.  *Note Fill Commands::.
   Many users like Auto Fill mode and want to use it in all text files.
The section on init files says how to arrange this permanently for
yourself.  *Note Init File::.
File: emacs,  Node: Fill Commands,  Next: Fill Prefix,  Prev: Auto Fill,  Up: Filling
Explicit Fill Commands
----------------------
`M-q'
     Fill current paragraph (`fill-paragraph').
`C-x f'
     Set the fill column (`set-fill-column').
`M-x fill-region'
     Fill each paragraph in the region (`fill-region').
`M-x fill-region-as-paragraph.'
     Fill the region, considering it as one paragraph.
`M-s'
     Center a line.
   To refill a paragraph, use the command `M-q' (`fill-paragraph').
This operates on the paragraph that point is inside, or the one after
point if point is between paragraphs.  Refilling works by removing all
the line-breaks, then inserting new ones where necessary.
   To refill many paragraphs, use `M-x fill-region', which divides the
region into paragraphs and fills each of them.
   `M-q' and `fill-region' use the same criteria as `M-h' for finding
paragraph boundaries (*note Paragraphs::.).  For more control, you can
use `M-x fill-region-as-paragraph', which refills everything between
point and mark.  This command deletes any blank lines within the
region, so separate blocks of text end up combined into one block.
   A numeric argument to `M-q' causes it to "justify" the text as well
as filling it.  This means that extra spaces are inserted to make the
right margin line up exactly at the fill column.  To remove the extra
spaces, use `M-q' with no argument.  (Likewise for `fill-region'.)
   When `adaptive-fill-mode' is non-`nil' (which is normally the case),
if you use `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.
   The command `M-s' (`center-line') centers the current line within
the current fill column.  With an argument N, it centers N lines
individually and moves past them.
   The maximum line width for filling is in the variable `fill-column'.
Altering the value of `fill-column' makes it local to the current
buffer; until that time, the default value is in effect.  The default
is initially 70.  *Note Locals::.  The easiest way to set `fill-column'
is to use the command `C-x f' (`set-fill-column').  With no argument,
it sets `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.
   If the variable `sentence-end-double-space' is `nil', the fill
commands expect and leave just one space at the end of a sentence.
Ordinarily this variable is `t', so the fill commands insist on two
spaces for the end of a sentence, as explained above.  *Note
Sentences::.
File: emacs,  Node: Fill Prefix,  Prev: Fill Commands,  Up: Filling
The Fill Prefix
---------------
   To fill a paragraph in which each line starts with a special marker
(which might be a few spaces, giving an indented paragraph), use the
"fill prefix" feature.  The fill prefix is a string which Emacs expects
every line to start with, and which is not included in filling.
`C-x .'
     Set the fill prefix (`set-fill-prefix').
`M-q'
     Fill a paragraph using current fill prefix (`fill-paragraph').
`M-x fill-individual-paragraphs'
     Fill the region, considering each change of indentation as
     starting a new paragraph.
`M-x fill-nonuniform-paragraphs'
     Fill the region, considering only paragraph-separator lines as
     starting a new paragraph.
   To specify a fill prefix, move to a line that starts with the desired
prefix, put point at the end of the prefix, and give the command
`C-x .' (`set-fill-prefix').  That's a period after the `C-x'.  To turn
off the fill prefix, specify an empty prefix: type `C-x .' with point
at the beginning of a line.
   When a fill prefix is in effect, the fill commands remove the fill
prefix from each line before filling and insert it on each line after
filling.  Auto Fill mode also inserts the fill prefix automatically when
it makes a new line.  The `C-o' command inserts the fill prefix on new
lines it creates, when you use it at the beginning of a line (*note
Blank Lines::.).  Conversely, the command `M-^' deletes the prefix (if
it occurs) after the newline that it deletes (*note Indentation::.).
   For example, if `fill-column' is 40 and you set the fill prefix to
`;; ', then `M-q' in the following text
     ;; This is an
     ;; example of a paragraph
     ;; inside a Lisp-style comment.
produces this:
     ;; This is an example of a paragraph
     ;; inside a Lisp-style comment.
   Lines that do not start with the fill prefix are considered to start
paragraphs, both in `M-q' and the paragraph commands; this 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.
   You can use `M-x fill-individual-paragraphs' to set the fill prefix
for each paragraph automatically.  This command divides the region into
paragraphs, treating every change in the amount of indentation as the
start of a new paragraph, and fills each of these paragraphs.  Thus,
all the lines in one "paragraph" have the same amount of indentation.
That indentation serves as the fill prefix for that paragraph.
   `M-x fill-nonuniform-paragraphs' is a similar command that divides
the region into paragraphs in a different way.  It considers only
paragraph-separating lines (as defined by `paragraph-separate') as
starting a new paragraph.  Since this means that the lines of one
paragraph may have different amounts of indentation, the fill prefix
used is the smallest amount of indentation of any of the lines of the
paragraph.  This gives good results with styles that indent a
paragraph's first line more or less that the rest of the paragraph.
   The fill prefix is stored in the variable `fill-prefix'.  Its value
is a string, or `nil' when there is no fill prefix.  This is a
per-buffer variable; altering the variable affects only the current
buffer, but there is a default value which you can change as well.
*Note Locals::.
File: emacs,  Node: Case,  Next: Text Mode,  Prev: Filling,  Up: Text
Case Conversion Commands
========================
   Emacs has commands for converting either a single word or any
arbitrary range of text to upper case or to lower case.
`M-l'
     Convert following word to lower case (`downcase-word').
`M-u'
     Convert following word to upper case (`upcase-word').
`M-c'
     Capitalize the following word (`capitalize-word').
`C-x C-l'
     Convert region to lower case (`downcase-region').
`C-x C-u'
     Convert region to upper case (`upcase-region').
   The word conversion commands are the most useful.  `M-l'
(`downcase-word') converts the word after point to lower case, moving
past it.  Thus, repeating `M-l' converts successive words.  `M-u'
(`upcase-word') converts to all capitals instead, while `M-c'
(`capitalize-word') puts the first letter of the word into upper case
and the rest into lower case.  All these commands convert several words
at once if given an argument.  They are especially convenient for
converting a large amount of text from all upper case to mixed case,
because you can move through the text using `M-l', `M-u' or `M-c' on
each word as appropriate, occasionally using `M-f' instead to skip a
word.
   When given a negative argument, the word case conversion commands
apply to the appropriate number of words before point, but do not move
point.  This is convenient when you have just typed a word in the wrong
case: you can give the case conversion command and continue typing.
   If a word case conversion command is given in the middle of a word,
it applies only to the part of the word which follows point.  This is
just like what `M-d' (`kill-word') does.  With a negative argument,
case conversion applies only to the part of the word before point.
   The other case conversion commands are `C-x C-u' (`upcase-region')
and `C-x C-l' (`downcase-region'), which convert everything between
point and mark to the specified case.  Point and mark do not move.
   The region case conversion commands `upcase-region' and
`downcase-region' are normally disabled.  This means that they ask for
confirmation if you try to use them.  When you confirm, you may enable
the command, which means it will not ask for confirmation again.  *Note
Disabling::.
File: emacs,  Node: Text Mode,  Next: Outline Mode,  Prev: Case,  Up: Text
Text Mode
=========
   When you edit files of text in a human language, it's more convenient
to use Text mode rather than Fundamental mode.  Invoke `M-x text-mode'
to enter Text mode.  In Text mode, TAB runs the function
`tab-to-tab-stop', which allows you to use arbitrary tab stops set with
`M-x edit-tab-stops' (*note 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.
   A similar variant mode is Indented Text mode, intended for editing
text in which most lines are indented.  This mode defines TAB to run
`indent-relative' (*note Indentation::.), and makes Auto Fill indent
the lines it creates.  The result is that normally a line made by Auto
Filling, or by LFD, is indented just like the previous line.  In
Indented Text mode, only blank lines separate paragraphs--indented
lines continue the current paragraph.  Use `M-x indented-text-mode' to
select this mode.
   Text mode, and all the modes based on it, define `M-TAB' as the
command `ispell-complete-word', which performs completion of the
partial word in the buffer before point, using the spelling dictionary
as the space of possible words.  *Note Spelling::.
   Entering Text mode or Indented 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 Nroff mode, TeX
mode, Outline mode and Mail mode.  Hook functions on `text-mode-hook'
can look at the value of `major-mode' to see which of these modes is
actually being entered.  *Note Hooks::.
* 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.
File: emacs,  Node: Outline Mode,  Next: TeX Mode,  Prev: Text Mode,  Up: Text
Outline Mode
============
   Outline mode is a major mode much like Text mode but intended for
editing outlines.  It allows you to make parts of the text temporarily
invisible so that you can see the outline structure.  Type `M-x
outline-mode' to switch to Outline mode as the major mode of the current
buffer.  Type `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
`C-c' prefix.  Outline minor mode provides similar bindings with `C-c
C-o' 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.)
   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, `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.
   Entering Outline mode runs the hook `text-mode-hook' followed by the
hook `outline-mode-hook' (*note Hooks::.).
* Menu:
* Format: Outline Format.       What the text of an outline looks like.
* Motion: Outline Motion.       Special commands for moving through
                                     outlines.
* Visibility: Outline Visibility.  Commands to control what is visible.
File: emacs,  Node: Outline Format,  Next: Outline Motion,  Up: Outline Mode
Format of Outlines
------------------
   Outline mode assumes that the lines in the buffer are of two types:
"heading lines" and "body lines".  A heading line represents a topic in
the outline.  Heading lines start with one or more stars; the number of
stars determines the depth of the heading in the outline structure.
Thus, a heading line with one star is a major topic; all the heading
lines with two stars between it and the next one-star heading are its
subtopics; and so on.  Any line that is not a heading line is a body
line.  Body lines belong with the preceding heading line.  Here is an
example:
     * Food

     This is the body,
     which says something about the topic of food.

     ** Delicious Food

     This is the body of the second-level header.

     ** Distasteful Food

     This could have
     a body too, with
     several lines.

     *** Dormitory Food

     * Shelter

     Another first-level topic with its header line.
   A heading line together with all following body lines is called
collectively an "entry".  A heading line together with all following
deeper heading lines and their body lines is called a "subtree".
   You can customize the criterion for distinguishing heading lines by
setting the variable `outline-regexp'.  Any line whose beginning has a
match for this regexp is considered a heading line.  Matches that start
within a line (not at the left margin) do not count.  The length of the
matching text determines the level of the heading; longer matches make
a more deeply nested level.  Thus, for example, if a text formatter has
commands `@chapter', `@section' and `@subsection' to divide the
document into chapters and sections, you could make those lines count
as heading lines by setting `outline-regexp' to
`"@chap\\|@\\(sub\\)*section"'.  Note the trick: the two words
`chapter' and `section' are equally long, but by defining the regexp to
match only `chap' we ensure that the length of the text matched on a
chapter heading is shorter, so that Outline mode will know that
sections are contained in chapters.  This works as long as no other
command starts with `@chap'.
   It is possible to change the rule for calculating the level of a
heading line by setting the variable `outline-level'.  The value of
`outline-level' should be a function that takes no arguments and
returns the level of the current heading.  Some major modes such as C,
Nroff, and Emacs Lisp mode set this variable in order to work with
Outline minor mode.
   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 *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.
File: emacs,  Node: Outline Motion,  Next: Outline Visibility,  Prev: Outline Format,  Up: Outline Mode
Outline Motion Commands
-----------------------
   There are some special motion commands in Outline mode that move
backward and forward to heading lines.
`C-c C-n'
     Move point to the next visible heading line
     (`outline-next-visible-heading').
`C-c C-p'
     Move point to the previous visible heading line
     (`outline-previous-visible-heading').
`C-c C-f'
     Move point to the next visible heading line at the same level as
     the one point is on (`outline-forward-same-level').
`C-c C-b'
     Move point to the previous visible heading line at the same level
     (`outline-backward-same-level').
`C-c C-u'
     Move point up to a lower-level (more inclusive) visible heading
     line (`outline-up-heading').
   `C-c C-n' (`next-visible-heading') moves down to the next heading
line.  `C-c C-p' (`previous-visible-heading') moves similarly backward.
Both accept numeric arguments as repeat counts.  The names emphasize
that invisible headings are skipped, but this is not really a special
feature.  All editing commands that look for lines ignore the invisible
lines automatically.
   More powerful motion commands understand the level structure of
headings.  `C-c C-f' (`outline-forward-same-level') and `C-c C-b'
(`outline-backward-same-level') move from one heading line to another
visible heading at the same depth in the outline.  `C-c C-u'
(`outline-up-heading') moves backward to another heading that is less
deeply nested.
File: emacs,  Node: Outline Visibility,  Prev: Outline Motion,  Up: Outline Mode
Outline Visibility Commands
---------------------------
   The other special commands of outline mode are used to make lines
visible or invisible.  Their names all start with `hide' or `show'.
Most of them fall into pairs of opposites.  They are not undoable;
instead, you can undo right past them.  Making lines visible or
invisible is simply not recorded by the undo mechanism.
`C-c C-t'
     Make all body lines in the buffer invisible (`hide-body').
`C-c C-a'
     Make all lines in the buffer visible (`show-all').
`C-c C-d'
     Make everything under this heading invisible, not including this
     heading itself
     (`hide-subtree').
`C-c C-s'
     Make everything under this heading visible, including body,
     subheadings, and their bodies (`show-subtree').
`C-c C-l'
     Make the body of this heading line, and of all its subheadings,
     invisible (`hide-leaves').
`C-c C-k'
     Make all subheadings of this heading line, at all levels, visible
     (`show-branches').
`C-c C-i'
     Make immediate subheadings (one level down) of this heading line
     visible (`show-children').
`C-c C-c'
     Make this heading line's body invisible (`hide-entry').
`C-c C-e'
     Make this heading line's body visible (`show-entry').
`C-c C-q'
     Hide everything except the top N levels of heading lines
     (`hide-sublevels').
`C-c C-o'
     Hide everything except for the heading or body that point is in,
     plus the headings leading up from there to the top level of the
     outline (`hide-other').
   Two commands that are exact opposites are `C-c C-c' (`hide-entry')
and `C-c C-e' (`show-entry').  They are used with point on a heading
line, and apply only to the body lines of that heading.  Subheadings
and their bodies are not affected.
   Two more powerful opposites are `C-c C-d' (`hide-subtree') and `C-c
C-s' (`show-subtree').  Both expect to be used when point is on a
heading line, and both apply to all the lines of that heading's
"subtree": its body, all its subheadings, both direct and indirect, and
all of their bodies.  In other words, the subtree contains everything
following this heading line, up to and not including the next heading of
the same or higher rank.
   Intermediate between a visible subtree and an invisible one is having
all the subheadings visible but none of the body.  There are two
commands for doing this, depending on whether you want to hide the
bodies or make the subheadings visible.  They are `C-c C-l'
(`hide-leaves') and `C-c C-k' (`show-branches').
   A little weaker than `show-branches' is `C-c C-i' (`show-children').
It makes just the direct subheadings visible--those one level down.
Deeper subheadings remain invisible, if they were invisible.
   Two commands have a blanket effect on the whole file.  `C-c C-t'
(`hide-body') makes all body lines invisible, so that you see just the
outline structure.  `C-c C-a' (`show-all') makes all lines visible.
These commands can be thought of as a pair of opposites even though
`C-c C-a' applies to more than just body lines.
   The command `C-c C-q' (`hide-sublevels') hides all but the top level
headings.  With a numeric argument N, it hides everything except the
top N levels of heading lines.
   The command `C-c C-o' (`hide-other') hides everything except the
heading or body text that point is in, plus its parents (the headers
leading up from there to top level in the outline).
   You can turn off the use of ellipses at the ends of visible lines by
setting `selective-display-ellipses' to `nil'.  Then there is no
visible indication of the presence of invisible lines.
File: emacs,  Node: TeX Mode,  Next: Nroff Mode,  Prev: Outline Mode,  Up: Text
TeX Mode
========
   TeX is a powerful text formatter written by Donald Knuth; it is also
free, like GNU Emacs.  LaTeX is a simplified input format for TeX,
implemented by TeX macros; it comes with TeX.  SliTeX is a special form
of LaTeX.
   Emacs has a special TeX mode for editing TeX input files.  It
provides facilities for checking the balance of delimiters and for
invoking TeX on all or part of the file.
   TeX mode has three variants, Plain TeX mode, LaTeX mode, and SliTeX
mode (these three distinct major modes differ only slightly).  They are
designed for editing the three different formats.  The command `M-x
tex-mode' looks at the contents of the buffer to determine whether the
contents appear to be either LaTeX input or SliTeX input; if so, it
selects the appropriate mode.  If the file contents do not appear to be
LaTeX or SliTeX, it selects Plain TeX mode.  If the contents are
insufficient to determine this, the variable `tex-default-mode'
controls which mode is used.
   When `M-x tex-mode' does not guess right, you can use the commands
`M-x plain-tex-mode', `M-x latex-mode', and `M-x slitex-mode' to select
explicitly the particular variants of TeX mode.
* Menu:
* Editing: TeX Editing.   Special commands for editing in TeX mode.
* LaTeX: LaTeX Editing.   Additional commands for LaTeX input files.
* Printing: TeX Print.    Commands for printing part of a file with TeX.
* Getting: TeX Distrib.   Getting the latest Unix TeX distribution.
File: emacs,  Node: TeX Editing,  Next: LaTeX Editing,  Up: TeX Mode
TeX Editing Commands
--------------------
   Here are the special commands provided in TeX mode for editing the
text of the file.
     Insert, according to context, either ```' or `"' or `'''
     (`tex-insert-quote').
`LFD'
     Insert a paragraph break (two newlines) and check the previous
     paragraph for unbalanced braces or dollar signs
     (`tex-terminate-paragraph').
`M-x validate-tex-region'
     Check each paragraph in the region for unbalanced braces or dollar
     signs.
`C-c {'
     Insert `{}' and position point between them (`tex-insert-braces').
`C-c }'
     Move forward past the next unmatched close brace (`up-list').
   In TeX, the character `"' is not normally used; we use ```' to start
a quotation and `''' to end one.  To make editing easier under this
formatting convention, TeX mode overrides the normal meaning of the key
`"' with a command that inserts a pair of single-quotes or backquotes
(`tex-insert-quote').  To be precise, this command inserts ```' after
whitespace or an open brace, `"' after a backslash, and `''' after any
other character.
   If you need the character `"' itself in unusual contexts, use `C-q'
to insert it.  Also, `"' with a numeric argument always inserts that
number of `"' characters.
   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.  LFD
(`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 (*note 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.
File: emacs,  Node: LaTeX Editing,  Next: TeX Print,  Prev: TeX Editing,  Up: TeX Mode
LaTeX Editing Commands
----------------------
   LaTeX mode, and its variant, SliTeX mode, provide a few extra
features not applicable to plain TeX.
`C-c C-o'
     Insert `\begin' and `\end' for LaTeX block and position point on a
     line between them. (`tex-latex-block').
`C-c C-e'
     Close the last unended block for LaTeX (`tex-close-latex-block').
   In LaTeX input, `\begin' and `\end' commands are used to group
blocks of text.  To insert a `\begin' and a matching `\end' (on a new
line following the `\begin'), use `C-c C-o' (`tex-latex-block').  A
blank line is inserted between the two, and point is left there.  You
can use completion when you enter the block type; to specify additional
block type names beyond the standard list, set the variable
`latex-block-names'.  For example, here's how to add `theorem',
`corollary', and `proof':
     (setq latex-block-names '("theorem" "corollary" "proof"))
   In LaTeX input, `\begin' and `\end' commands must balance.  You can
use `C-c C-e' (`tex-close-latex-block') to insert automatically a
matching `\end' to match the last unmatched `\begin'.  It indents the
`\end' to match the corresponding `\begin'.  It inserts a newline after
`\end' if point is at the beginning of a line.
File: emacs,  Node: TeX Print,  Next: TeX Distrib,  Prev: LaTeX Editing,  Up: TeX Mode
TeX Printing Commands
---------------------
   You can invoke TeX as an inferior of Emacs on either the entire
contents of the buffer or just a region at a time.  Running TeX in this
way on just one chapter is a good way to see what your changes look
like without taking the time to format the entire file.
`C-c C-r'
     Invoke TeX on the current region, together with the buffer's header
     (`tex-region').
`C-c C-b'
     Invoke TeX on the entire current buffer (`tex-buffer').
`C-c TAB'
     Invoke BibTeX on the current file (`tex-bibtex-file').
`C-c C-f'
     Invoke TeX on the current file (`tex-file').
`C-c C-l'
     Recenter the window showing output from the inferior TeX so that
     the last line can be seen (`tex-recenter-output-buffer').
`C-c C-k'
     Kill the TeX subprocess (`tex-kill-job').
`C-c C-p'
     Print the output from the last `C-c C-r', `C-c C-b', or `C-c C-f'
     command (`tex-print').
`C-c C-v'
     Preview the output from the last `C-c C-r', `C-c C-b', or `C-c
     C-f' command (`tex-view').
`C-c C-q'
     Show the printer queue (`tex-show-print-queue').
   You can pass the current buffer through an inferior TeX by means of
`C-c C-b' (`tex-buffer').  The formatted output appears in a temporary
file; to print it, type `C-c C-p' (`tex-print').  Afterward, you can
use `C-c C-q' (`tex-show-print-queue') to view the progress of your
output towards being printed.  If your terminal has the ability to
display TeX output files, you can preview the output on the terminal
with `C-c C-v' (`tex-view').
   You can specify the directory to use for running TeX by setting the
variable `tex-directory'.  `"."' is the default value.  If your
environment variable `TEXINPUTS' contains relative directory names, or
if your files contains `\input' commands with relative file names, then
`tex-directory' *must* be `"."' or you will get the wrong results.
Otherwise, it is safe to specify some other directory, such as `"/tmp"'.
   If you want to specify which shell commands are used in the inferior
TeX, you can do so by setting the values of the variables
`tex-run-command', `latex-run-command', `slitex-run-command',
`tex-dvi-print-command', `tex-dvi-view-command', and
`tex-show-queue-command'.  You *must* set the value of
`tex-dvi-view-command' for your particular terminal; this variable has
no default value.  The other variables have default values that may (or
may not) be appropriate for your system.
   Normally, the file name given to these commands comes at the end of
the command string; for example, `latex FILENAME'.  In some cases,
however, the file name needs to be embedded in the command; an example
is when you need to provide the file name as an argument to one command
whose output is piped to another.  You can specify where to put the
file name with `*' in the command string.  For example,
     (setq tex-dvi-print-command "dvips -f * | lpr")
   The terminal output from TeX, including any error messages, appears
in a buffer called `*tex-shell*'.  If TeX gets an error, you can switch
to this buffer and feed it input (this works as in Shell mode; *note
Interactive Shell::.).  Without switching to this buffer you can scroll
it so that its last line is visible by typing `C-c C-l'.
   Type `C-c C-k' (`tex-kill-job') to kill the TeX process if you see
that its output is no longer useful.  Using `C-c C-b' or `C-c C-r' also
kills any TeX process still running.
   You can also pass an arbitrary region through an inferior TeX by
typing `C-c C-r' (`tex-region').  This is tricky, however, because most
files of TeX input contain commands at the beginning to set parameters
and define macros, without which no later part of the file will format
correctly.  To solve this problem, `C-c C-r' allows you to designate a
part of the file as containing essential commands; it is included before
the specified region as part of the input to TeX.  The designated part
of the file is called the "header".
   To indicate the bounds of the header in Plain TeX mode, you insert
two special strings in the file.  Insert `%**start of header' before the
header, and `%**end of header' after it.  Each string must appear
entirely on one line, but there may be other text on the line before or
after.  The lines containing the two strings are included in the header.
If `%**start of header' does not appear within the first 100 lines of
the buffer, `C-c C-r' assumes that there is no header.
   In LaTeX mode, the header begins with `\documentstyle' and ends with
`\begin{document}'.  These are commands that LaTeX requires you to use
in any case, so nothing special needs to be done to identify the header.
   The commands (`tex-buffer') and (`tex-region') do all of their work
in a temporary directory, and do not have available any of the auxiliary
files needed by TeX for cross-references; these commands are generally
not suitable for running the final copy in which all of the
cross-references need to be correct.  When you want the auxiliary
files, use `C-c C-f' (`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
(`tex-file') twice to get cross-references correct.
   For LaTeX files, you can use BibTeX to process the auxiliary file
for the current buffer's file.  BibTeX looks up bibliographic citations
in a data base and prepares the cited references for the bibliography
section.  The command `C-c TAB' (`tex-bibtex-file') runs the shell
command (`tex-bibtex-command') to produce a `.bbl' file for the current
buffer's file.  Generally, you need to do `C-c C-f' (`tex-file') once
to generate the `.aux' file, then do `C-c TAB' (`tex-bibtex-file'), and
then repeat `C-c C-f' (`tex-file') twice more to get the
cross-references correct.
   Entering any kind of TeX mode runs the hooks `text-mode-hook' and
`tex-mode-hook'.  Then it runs either `plain-tex-mode-hook' or
`latex-mode-hook', whichever is appropriate.  For SliTeX files, it
calls `slitex-mode-hook'.  Starting the TeX shell runs the hook
`tex-shell-hook'.  *Note Hooks::.
File: emacs,  Node: TeX Distrib,  Prev: TeX Print,  Up: TeX Mode
Unix TeX Distribution
---------------------
   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:
     Pierre MacKay
     Department of Classics
     Denny Hall, Mail Stop DH-10
     University of Washington
     Seattle, Washington 98195
Purchase orders are acceptable, but there is an extra charge of $10.00,
to pay for processing charges.
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.
File: emacs,  Node: Nroff Mode,  Prev: TeX Mode,  Up: Text
Nroff Mode
==========
   Nroff mode is a mode like Text mode but modified to handle nroff
commands present in the text.  Invoke `M-x nroff-mode' to enter this
mode.  It differs from Text mode in only a few ways.  All nroff command
lines are considered paragraph separators, so that filling will never
garble the nroff commands.  Pages are separated by `.bp' commands.
Comments start with backslash-doublequote.  Also, three special
commands are provided that are not in Text mode:
`M-n'
     Move to the beginning of the next line that isn't an nroff command
     (`forward-text-line').  An argument is a repeat count.
`M-p'
     Like `M-n' but move up (`backward-text-line').
`M-?'
     Prints in the echo area the number of text lines (lines that are
     not nroff commands) in the region (`count-text-lines').
   The other feature of Nroff mode is that you can turn on Electric
Nroff mode.  This is a minor mode that you can turn on or off with `M-x
electric-nroff-mode' (*note Minor Modes::.).  When the mode is on, each
time you use RET to end a line that contains an nroff command that
opens a kind of grouping, the matching nroff command to close that
grouping is automatically inserted on the following line.  For example,
if you are at the beginning of a line and type `. ( b RET', this
inserts the matching command `.)b' on a new line following point.
   If you use Outline minor mode with Nroff mode (*note Outline
Mode::.), heading lines are lines of the form `.H' followed by a number
(the header level).
   Entering Nroff mode runs the hook `text-mode-hook', followed by the
hook `nroff-mode-hook' (*note Hooks::.).
File: emacs,  Node: Programs,  Next: Building,  Prev: Text,  Up: Top
Editing Programs
****************
   Emacs has many commands designed to understand the syntax of
programming languages such as Lisp and C.  These commands can
   * Move over or kill balanced expressions or "sexps" (*note Lists::.).
   * Move over or mark top-level expressions--"defuns", in Lisp;
     functions, in C (*note Defuns::.).
   * Show how parentheses balance (*note Matching::.).
   * Insert, kill or align comments (*note Comments::.).
   * Follow the usual indentation conventions of the language (*note
     Program Indent::.).
   The commands for words, sentences and paragraphs are very useful in
editing code even though their canonical application is for editing
human language text.  Most symbols contain words (*note Words::.);
sentences can be found in strings and comments (*note Sentences::.).
Paragraphs per se don't exist in code, but the paragraph commands are
useful anyway, because programming language major modes define
paragraphs to begin and end at blank lines (*note Paragraphs::.).
Judicious use of blank lines to make the program clearer will also
provide useful chunks of text for the paragraph commands to work on.
   The selective display feature is useful for looking at the overall
structure of a function (*note Selective Display::.).  This feature
causes only the lines that are indented less than a specified amount to
appear on the screen.
* Menu:
* Program Modes::     Major modes for editing programs.
* Lists::             Expressions with balanced parentheses.
* List Commands::     The commands for working with list and sexps.
* Defuns::            Each program is made up of separate functions.
                        There are editing commands to operate on them.
* Program Indent::    Adjusting indentation to show the nesting.
* Matching::          Insertion of a close-delimiter flashes matching open.
* Comments::          Inserting, killing, and aligning comments.
* Balanced Editing::  Inserting two matching parentheses at once, etc.
* Symbol Completion:: Completion on symbol names of your program or language.
* Documentation::     Getting documentation of functions you plan to call.
* Change Log::        Maintaining a change history for your program.
* Tags::              Go direct to any function in your program in one
                        command.  Tags remembers which file it is in.
* Emerge::          A convenient way of merging two versions of a program.
* C Mode::          Special commands of C mode (and C++ mode).
* Fortran::          Fortran mode and its special features.
* Asm Mode::          Asm mode and its special features.
File: emacs,  Node: Program Modes,  Next: Lists,  Up: Programs
Major Modes for Programming Languages
=====================================
   Emacs also has major modes for the programming languages Lisp, Scheme
(a variant of Lisp), Awk, C, C++, Fortran, Icon, Pascal, Perl and Tcl.
There is also a major mode for makefiles, called Makefile mode.
   Ideally, a major mode should be implemented for each programming
language that you might want to edit with Emacs; but often the mode for
one language can serve for other syntactically similar languages.  The
language modes that exist are those that someone decided to take the
trouble to write.
   There are several forms of Lisp mode, which differ in the way they
interface to Lisp execution.  *Note Executing Lisp::.
   Each of the programming language modes defines the TAB key to run an
indentation function that knows the indentation conventions of that
language and updates the current line's indentation accordingly.  For
example, in C mode TAB is bound to `c-indent-line'.  LFD is normally
defined to do RET followed by TAB; thus, it too indents in a
mode-specific fashion.
   In most programming languages, indentation is likely to vary from
line to line.  So the major modes for those languages rebind DEL to
treat a tab as if it were the equivalent number of spaces (using the
command `backward-delete-char-untabify').  This makes it possible to
rub out indentation one column at a time without worrying whether it is
made up of spaces or tabs.  Use `C-b C-d' to delete a tab character
before point, in these modes.
   Programming language modes define paragraphs to be separated only by
blank lines, so that the paragraph commands remain useful.  Auto Fill
mode, if enabled in a programming language major mode, indents the new
lines which it creates.
   Turning on a major mode runs a normal hook called the "mode hook",
which is the value of a Lisp variable.  Each major mode has a mode hook,
and the hook's name is always made from the mode command's name by
adding `-hook'.  For example, turning on C mode runs the hook
`c-mode-hook', while turning on Lisp mode runs the hook
`lisp-mode-hook'.  *Note Hooks::.
File: emacs,  Node: Lists,  Next: List Commands,  Prev: Program Modes,  Up: Programs
Lists and Sexps
===============
   By convention, Emacs keys for dealing with balanced expressions are
usually Control-Meta characters.  They tend to be analogous in function
to their Control and Meta equivalents.  These commands are usually
thought of as pertaining to expressions in programming languages, but
can be useful with any language in which some sort of parentheses exist
(including human languages).
   These commands fall into two classes.  Some deal only with "lists"
(parenthetical groupings).  They see nothing except parentheses,
brackets, braces (whichever ones must balance in the language you are
working with), and escape characters that might be used to quote those.
   The other commands deal with expressions or "sexps".  The word `sexp'
is derived from "s-expression", the ancient term for an expression in
Lisp.  But in Emacs, the notion of `sexp' is not limited to Lisp.  It
refers to an expression in whatever language your program is written in.
Each programming language has its own major mode, which customizes the
syntax tables so that expressions in that language count as sexps.
   Sexps typically include symbols, numbers, and string constants, as
well as anything contained in parentheses, brackets or braces.
   In languages that use prefix and infix operators, such as C, it is
not possible for all expressions to be sexps.  For example, C mode does
not recognize `foo + bar' as a sexp, even though it *is* a C expression;
it recognizes `foo' as one sexp and `bar' as another, with the `+' as
punctuation between them.  This is a fundamental ambiguity: both `foo +
bar' and `foo' are legitimate choices for the sexp to move over if
point is at the `f'.  Note that `(foo + bar)' is a single sexp in C
mode.
   Some languages have obscure forms of expression syntax that nobody
has bothered to make Emacs understand properly.
File: emacs,  Node: List Commands,  Next: Defuns,  Prev: Lists,  Up: Programs
List And Sexp Commands
======================
`C-M-f'
     Move forward over a sexp (`forward-sexp').
`C-M-b'
     Move backward over a sexp (`backward-sexp').
`C-M-k'
     Kill sexp forward (`kill-sexp').
`C-M-DEL'
     Kill sexp backward (`backward-kill-sexp').
`C-M-u'
     Move up and backward in list structure (`backward-up-list').
`C-M-d'
     Move down and forward in list structure (`down-list').
`C-M-n'
     Move forward over a list (`forward-list').
`C-M-p'
     Move backward over a list (`backward-list').
`C-M-t'
     Transpose expressions (`transpose-sexps').
`C-M-@'
     Put mark after following expression (`mark-sexp').
   To move forward over a sexp, use `C-M-f' (`forward-sexp').  If the
first significant character after point is an opening delimiter (`(' in
Lisp; `(', `[' or `{' in C), `C-M-f' moves past the matching closing
delimiter.  If the character begins a symbol, string, or number,
`C-M-f' moves over that.
   The command `C-M-b' (`backward-sexp') moves backward over a sexp.
The detailed rules are like those above for `C-M-f', but with
directions reversed.  If there are any prefix characters (single-quote,
backquote and comma, in Lisp) preceding the sexp, `C-M-b' moves back
over them as well.  The sexp commands move across comments as if they
were whitespace in most modes.
   `C-M-f' or `C-M-b' with an argument repeats that operation the
specified number of times; with a negative argument, it moves in the
opposite direction.
   Killing a sexp at a time can be done with `C-M-k' (`kill-sexp') or
`C-M-DEL' (`backward-kill-sexp').  `C-M-k' kills the characters that
`C-M-f' would move over, and `C-M-DEL' kills the characters that
`C-M-b' would move over.
   The "list commands" move over lists like the sexp commands but skip
blithely over any number of other kinds of sexps (symbols, strings,
etc).  They are `C-M-n' (`forward-list') and `C-M-p' (`backward-list').
The main reason they are useful is that they usually ignore comments
(since the comments usually do not contain any lists).
   `C-M-n' and `C-M-p' stay at the same level in parentheses, when
that's possible.  To move *up* one (or N) levels, use `C-M-u'
(`backward-up-list').  `C-M-u' moves backward up past one unmatched
opening delimiter.  A positive argument serves as a repeat count; a
negative argument reverses direction of motion and also requests
repetition, so it moves forward and up one or more levels.
   To move *down* in list structure, use `C-M-d' (`down-list').  In
Lisp mode, where `(' is the only opening delimiter, this is nearly the
same as searching for a `('.  An argument specifies the number of levels
of parentheses to go down.
   A somewhat random-sounding command which is nevertheless handy is
`C-M-t' (`transpose-sexps'), which drags the previous sexp across the
next one.  An argument serves as a repeat count, and a negative
argument drags backwards (thus canceling out the effect of `C-M-t' with
a positive argument).  An argument of zero, rather than doing nothing,
transposes the sexps ending after point and the mark.
   To set the region around the next sexp in the buffer, use `C-M-@'
(`mark-sexp'), which sets mark at the same place that `C-M-f' would
move to.  `C-M-@' takes arguments like `C-M-f'.  In particular, a
negative argument is useful for putting the mark at the beginning of
the previous sexp.
   The list and sexp commands' understanding of syntax is completely
controlled by the syntax table.  Any character can, for example, be
declared to be an opening delimiter and act like an open parenthesis.
*Note Syntax::.