OS/2 Professional/OS2PRO194.ISO/os2/prgramer/unix/info/emacs.i10

GNU Info File | 1993-06-14 | 52KB | 872 lines

This is Info file ../info/emacs, produced by Makeinfo-1.47 from the
input file emacs.tex.
   This file documents the GNU Emacs editor.
   Copyright (C) 1985, 1986, 1988 Richard M. Stallman.
   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "The GNU Manifesto", "Distribution" and "GNU
General Public License" are included exactly as in the original, and
provided that the entire resulting derived work is distributed under the
terms of a permission notice identical to this one.
   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "The GNU Manifesto",
"Distribution" and "GNU General Public License" may be included in a
translation approved by the author instead of in the original English.
File: emacs,  Node: Rmail Deletion,  Next: Rmail Inbox,  Prev: Rmail Motion,  Up: Rmail
Deleting Messages
=================
   When you no longer need to keep a message, you can "delete" it.  This
flags it as ignorable, and some Rmail commands will pretend it is no
longer present; but it still has its place in the Rmail file, and still
has its message number.
   "Expunging" the Rmail file actually removes the deleted messages.
The remaining messages are renumbered consecutively.  Expunging is the
only action that changes the message number of any message, except for
undigestifying (*note Rmail Digest::.).
     Delete the current message, and move to the next nondeleted message
     (`rmail-delete-forward').
`C-d'
     Delete the current message, and move to the previous nondeleted
     message (`rmail-delete-backward').
     Undelete the current message, or move back to a deleted message and
     undelete it (`rmail-undelete-previous-message').
     Expunge the Rmail file (`rmail-expunge').  These two commands are
     synonyms.
   There are two Rmail commands for deleting messages.  Both delete the
current message and select another message.  `d'
(`rmail-delete-forward') moves to the following message, skipping
messages already deleted, while `C-d' (`rmail-delete-backward') moves
to the previous nondeleted message. If there is no nondeleted message
to move to in the specified direction, the message that was just
deleted remains current.
   To make all the deleted messages finally vanish from the Rmail file,
type `e' (`rmail-expunge').  Until you do this, you can still "undelete"
the deleted messages.
   To undelete, type `u' (`rmail-undelete-previous-message'), which is
designed to cancel the effect of a `d' command (usually).  It undeletes
the current message if the current message is deleted.  Otherwise it
moves backward to previous messages until a deleted message is found,
and undeletes that message.
   You can usually undo a `d' with a `u' because the `u' moves back to
and undeletes the message that the `d' deleted.  But this does not work
when the `d' skips a few already-deleted messages that follow the
message being deleted; then the `u' command will undelete the last of
the messages that were skipped.  There is no clean way to avoid this
problem.  However, by repeating the `u' command, you can eventually get
back to the message that you intended to undelete.  You can also reach
that message with `M-p' commands and then type `u'.
   A deleted message has the `deleted' attribute, and as a result
`deleted' appears in the mode line when the current message is deleted.
 In fact, deleting or undeleting a message is nothing more than adding
or removing this attribute.  *Note Rmail Labels::.
File: emacs,  Node: Rmail Inbox,  Next: Rmail Files,  Prev: Rmail Deletion,  Up: Rmail
Rmail Files and Inboxes
=======================
   Unix places incoming mail for you in a file that we call your
"inbox". When you start up Rmail, it copies the new messages from your
inbox into your primary mail file, an Rmail file, which also contains
other messages saved from previous Rmail sessions.  It is in this file
that you actually read the mail with Rmail.  This operation is called
"getting new mail". It can be repeated at any time using the `g' key in
Rmail.  The inbox file name is `/usr/spool/mail/USERNAME' in Berkeley
Unix, `/usr/mail/USERNAME' in system V.
   There are two reason for having separate Rmail files and inboxes.
  1. The format in which Unix delivers the mail in the inbox is not
     adequate for Rmail mail storage.  It has no way to record
     attributes (such as `deleted') or user-specified labels; it has no
     way to record old headers and reformatted headers; it has no way
     to record cached summary line information.
  2. It is very cumbersome to access an inbox file without danger of
     losing mail, because it is necessary to interlock with mail
     delivery. Moreover, different Unix systems use different
     interlocking techniques.  The strategy of moving mail out of the
     inbox once and for all into a separate Rmail file avoids the need
     for interlocking in all the rest of Rmail, since only Rmail
     operates on the Rmail file.
   When getting new mail, Rmail first copies the new mail from the inbox
file to the Rmail file; then it saves the Rmail file; then it deletes
the inbox file.  This way, a system crash may cause duplication of mail
between the inbox and the Rmail file, but cannot lose mail.
   Copying mail from an inbox in the system's mailer directory actually
puts it in an intermediate file `~/.newmail'.  This is because the
interlocking is done by a C program that copies to another file.
`~/.newmail' is deleted after mail merging is successful.  If there is
a crash at the wrong time, this file will continue to exist and will be
used as an inbox the next time you get new mail.
File: emacs,  Node: Rmail Files,  Next: Rmail Output,  Prev: Rmail Inbox,  Up: Rmail
Multiple Mail Files
===================
   Rmail operates by default on your "primary mail file", which is named
`~/RMAIL' and receives your incoming mail from your system inbox file.
But you can also have other mail files and edit them with Rmail.  These
files can receive mail through their own inboxes, or you can move
messages into them by explicit command in Rmail (*note Rmail Output::.).
`i FILE RET'
     Read FILE into Emacs and run Rmail on it (`rmail-input').
`M-x set-rmail-inbox-list RET FILES RET'
     Specify inbox file names for current Rmail file to get mail from.
     Merge new mail from current Rmail file's inboxes
     (`rmail-get-new-mail').
`C-u g FILE'
     Merge new mail from inbox file FILE.
   To run Rmail on a file other than your primary mail file, you may
use the `i' (`rmail-input') command in Rmail.  This visits the file,
puts it in Rmail mode, and then gets new mail from the file's inboxes
if any. You can also use `M-x rmail-input' even when not in Rmail.
   The file you read with `i' does not have to be in Rmail file format.
It could also be Unix mail format, or mmdf format; or it could be a
mixture of all three, as long as each message belongs to one of the
three formats. Rmail recognizes all three and converts all the messages
to proper Rmail format before showing you the file.
   Each Rmail file can contain a list of inbox file names; you can
specify this list with `M-x set-rmail-inbox-list RET FILES RET'.  The
argument can contain any number of file names, separated by commas.  It
can also be empty, which specifies that this file should have no
inboxes.  Once a list of inboxes is specified, the Rmail file remembers
it permanently until it is explicitly changed.
   If an Rmail file has inboxes, new mail is merged in from the inboxes
when the Rmail file is brought into Rmail, and when the `g'
(`rmail-get-new-mail') command is used.  If the Rmail file specifies no
inboxes, then no new mail is merged in at these times.  A special
exception is made for your primary mail file in using the standard
system inbox for it if it does not specify any.
   To merge mail from a file that is not the usual inbox, give the `g'
key a numeric argument, as in `C-u g'.  Then it reads a file name and
merges mail from that file.  The inbox file is not deleted or changed in
any way when `g' with an argument is used.  This is, therefore, a
general way of merging one file of messages into another.
File: emacs,  Node: Rmail Output,  Next: Rmail Labels,  Prev: Rmail Files,  Up: Rmail
Copying Messages Out to Files
=============================
`o FILE RET'
     Append a copy of the current message to the file FILE, writing it
     in Rmail file format (`rmail-output-to-rmail-file').
`C-o FILE RET'
     Append a copy of the current message to the file FILE, writing it
     in Unix mail file format (`rmail-output').
   If an Rmail file has no inboxes, how does it get anything in it?  By
explicit `o' commands.
   `o' (`rmail-output-to-rmail-file') appends the current message in
Rmail format to the end of the specified file.  This is the best command
to use to move messages between Rmail files.  If the other Rmail file is
currently visited, the copying is done into the other file's Emacs
buffer instead.  You should eventually save it on disk.
   The `C-o' (`rmail-output') command in Rmail appends a copy of the
current message to a specified file, in Unix mail file format.  This is
useful for moving messages into files to be read by other mail
processors that do not understand Rmail format.
   Copying a message with `o' or `C-o' gives the original copy of the
message the `filed' attribute, so that `filed' appears in the mode line
when such a message is current.
   Normally you should use only `o' to output messages to other Rmail
files, never `C-o'.  But it is also safe if you always use `C-o', never
`o'.  When a file is visited in Rmail, the last message is checked, and
if it is in Unix format, the entire file is scanned and all Unix-format
messages are converted to Rmail format.  (The reason for checking the
last message is that scanning the file is slow and most Rmail files
have only Rmail format messages.)  If you use `C-o' consistently, the
last message is sure to be in Unix format, so Rmail will convert all
messages properly.
   The case where you might want to use `C-o' always, instead of `o'
always, is when you or other users want to append mail to the same file
from other mail processors.  Other mail processors probably do not know
Rmail format but do know Unix format.
   In any case, always use `o' to add to an Rmail file that is being
visited in Rmail.  Adding messages with `C-o' to the actual disk file
will trigger a "simultaneous editing" warning when you ask to save the
Emacs buffer, and will be lost if you do save.
File: emacs,  Node: Rmail Labels,  Next: Rmail Summary,  Prev: Rmail Output,  Up: Rmail
Labels
======
   Each message can have various "labels" assigned to it as a means of
classification.  A label has a name; different names mean different
labels. Any given label is either present or absent on a particular
message.  A few label names have standard meanings and are given to
messages automatically by Rmail when appropriate; these special labels
are called "attributes". All other labels are assigned by the user.
`a LABEL RET'
     Assign the label LABEL to the current message (`rmail-add-label').
`k LABEL RET'
     Remove the label LABEL from the current message
     (`rmail-kill-label').
`C-M-n LABELS RET'
     Move to the next message that has one of the labels LABELS
     (`rmail-next-labeled-message').
`C-M-p LABELS RET'
     Move to the previous message that has one of the labels LABELS
     (`rmail-previous-labeled-message').
`C-M-l LABELS RET'
     Make a summary of all messages containing any of the labels LABELS
     (`rmail-summary-by-labels').
Specifying an empty string for one these commands means to use the last
label specified for any of these commands.
   The `a' (`rmail-add-label') and `k' (`rmail-kill-label') commands
allow you to assign or remove any label on the current message.  If the
LABEL argument is empty, it means to assign or remove the same label
most recently assigned or removed.
   Once you have given messages labels to classify them as you wish,
there are two ways to use the labels: in moving and in summaries.
   The command `C-M-n LABELS RET' (`rmail-next-labeled-message') moves
to the next message that has one of the labels LABELS.  LABELS is one
or more label names, separated by commas.  `C-M-p'
(`rmail-previous-labeled-message') is similar, but moves backwards to
previous messages.  A preceding numeric argument to either one serves
as a repeat count.
   The command `C-M-l LABELS RET' (`rmail-summary-by-labels') displays
a summary containing only the messages that have at least one of a
specified set of messages.  The argument LABELS is one or more label
names, separated by commas. *Note Rmail Summary::, for information on
summaries.
   If the LABELS argument to `C-M-n', `C-M-p' or `C-M-l' is empty, it
means to use the last set of labels specified for any of these commands.
   Some labels such as `deleted' and `filed' have built-in meanings and
are assigned to or removed from messages automatically at appropriate
times; these labels are called "attributes".  Here is a list of Rmail
attributes:
`unseen'
     Means the message has never been current.  Assigned to messages
     when they come from an inbox file, and removed when a message is
     made current.
`deleted'
     Means the message is deleted.  Assigned by deletion commands and
     removed by undeletion commands (*note Rmail Deletion::.).
`filed'
     Means the message has been copied to some other file.  Assigned by
     the file output commands (*note Rmail Files::.).
`answered'
     Means you have mailed an answer to the message.  Assigned by the
     `r' command (`rmail-reply').  *Note Rmail Reply::.
`forwarded'
     Means you have forwarded the message to other users.  Assigned by
     the `f' command (`rmail-forward').  *Note Rmail Reply::.
`edited'
     Means you have edited the text of the message within Rmail. *Note
     Rmail Editing::.
   All other labels are assigned or removed only by the user, and it is
up to the user to decide what they mean.
File: emacs,  Node: Rmail Summary,  Next: Rmail Reply,  Prev: Rmail Labels,  Up: Rmail
Summaries
=========
   A "summary" is a buffer containing one line per message that Rmail
can make and display to give you an overview of the mail in an Rmail
file. Each line shows the message number, the sender, the labels, and
the subject.  When the summary buffer is selected, various commands can
be used to select messages by moving in the summary buffer, or delete
or undelete messages.
   A summary buffer applies to a single Rmail file only; if you are
editing multiple Rmail files, they have separate summary buffers.  The
summary buffer name is made by appending `-summary' to the Rmail
buffer's name.  Only one summary buffer will be displayed at a time
unless you make several windows and select the summary buffers by hand.
* Menu:
* Rmail Make Summary::  Making various sorts of summaries.
* Rmail Summary Edit::  Manipulating messages from the summary.
File: emacs,  Node: Rmail Make Summary,  Next: Rmail Summary Edit,  Prev: Rmail Summary,  Up: Rmail Summary
Making Summaries
----------------
   Here are the commands to create a summary for the current Rmail file.
Summaries do not update automatically; to make an updated summary, you
must use one of these commands again.
`C-M-h'
     Summarize all messages (`rmail-summary').
`l LABELS RET'
`C-M-l LABELS RET'
     Summarize message that have one or more of the specified labels
     (`rmail-summary-by-labels').
`C-M-r RCPTS RET'
     Summarize messages that have one or more of the specified
     recipients (`rmail-summary-by-recipients')
   The `h' or `C-M-h' (`rmail-summary') command fills the summary buffer
for the current Rmail file with a summary of all the messages in the
file. It then displays and selects the summary buffer in another window.
   `C-M-l LABELS RET' (`rmail-summary-by-labels') makes a partial
summary mentioning only the messages that have one or more of the
labels LABELS.  LABELS should contain label names separated by commas.
   `C-M-r RCPTS RET' (`rmail-summary-by-recipients') makes a partial
summary mentioning only the messages that have one or more of the
recipients RCPTS.  RCPTS should contain mailing addresses separated by
commas.
   Note that there is only one summary buffer for any Rmail file;
making one kind of summary discards any previously made summary.
File: emacs,  Node: Rmail Summary Edit,  Prev: Rmail Make Summary,  Up: Rmail Summary
Editing in Summaries
--------------------
   Summary buffers are given the major mode Rmail Summary mode, which
provides the following special commands:
     Select the message described by the line that point is on
     (`rmail-summary-goto-msg').
`C-n'
     Move to next line and select its message in Rmail
     (`rmail-summary-next-all').
`C-p'
     Move to previous line and select its message
     (`rmail-summary-previous-all').
     Move to next line, skipping lines saying `deleted', and select its
     message (`rmail-summary-next-msg').
     Move to previous line, skipping lines saying `deleted', and select
     its message (`rmail-summary-previous-msg').
     Delete the current line's message, then do like `n'
     (`rmail-summary-delete-forward').
     Undelete and select this message or the previous deleted message in
     the summary (`rmail-summary-undelete').
`SPC'
     Scroll the other window (presumably Rmail) forward
     (`rmail-summary-scroll-msg-up').
`DEL'
     Scroll the other window backward (`rmail-summary-scroll-msg-down').
     Kill the summary window (`rmail-summary-exit').
     Exit Rmail (`rmail-summary-quit').
   The keys `C-n' and `C-p' are modified in Rmail Summary mode so that
in addition to moving point in the summary buffer they also cause the
line's message to become current in the associated Rmail buffer.  That
buffer is also made visible in another window if it is not already so.
   `n' and `p' are similar to `C-n' and `C-p', but skip lines that say
`message deleted'.  They are like the `n' and `p' keys of Rmail itself.
 Note, however, that in a partial summary these commands move only
among the message listed in the summary.
   The other Emacs cursor motion commands are not changed in Rmail
Summary mode, so it is easy to get the point on a line whose message is
not selected in Rmail.  This can also happen if you switch to the Rmail
window and switch messages there.  To get the Rmail buffer back in sync
with the summary, use the `j' (`rmail-summary-goto-msg') command, which
selects in Rmail the message of the current summary line.
   Deletion and undeletion can also be done from the summary buffer.
They always work based on where point is located in the summary buffer,
ignoring which message is selected in Rmail.  `d'
(`rmail-summary-delete-forward') deletes the current line's message,
then moves to the next line whose message is not deleted and selects
that message.  The inverse of this is `u' (`rmail-summary-undelete'),
which moves back (if necessary) to a line whose message is deleted,
undeletes that message, and selects it in Rmail.
   When moving through messages with the summary buffer, it is
convenient to be able to scroll the message while remaining in the
summary window. The commands SPC (`rmail-summary-scroll-msg-up') and DEL
(`rmail-summary-scroll-msg-down') do this.  They scroll the message just
as those same keys do when the Rmail buffer is selected.
   When you are finished using the summary, type `x'
(`rmail-summary-exit') to kill the summary buffer's window.
   You can also exit Rmail while in the summary.  `q'
(`rmail-summary-quit') kills the summary window, then saves the Rmail
file and switches to another buffer.
File: emacs,  Node: Rmail Reply,  Next: Rmail Editing,  Prev: Rmail Summary,  Up: Rmail
Sending Replies
===============
   Rmail has several commands that use Mail mode to send outgoing mail.
*Note Sending Mail::, for information on using Mail mode.  What are
documented here are the special commands of Rmail for entering Mail
mode. Note that the usual keys for sending mail, `C-x m' and `C-x 4 m',
are available in Rmail mode and work just as they usually do.
     Send a message (`rmail-mail').
     Continue editing already started outgoing message
     (`rmail-continue').
     Send a reply to the current Rmail message (`rmail-reply').
     Forward current message to other users (`rmail-forward').
   The most common reason to send a message while in Rmail is to reply
to the message you are reading.  To do this, type `r' (`rmail-reply').
This displays the `*mail*' buffer in another window, much like `C-x 4
m', but preinitializes the `Subject', `To', `CC' and `In-reply-to'
header fields based on the message being replied to.  The `To' field is
given the sender of that message, and the `CC' gets all the recipients
of that message (but recipients that match elements of the list
`rmail-dont-reply-to' are omitted; by default, this list contains your
own mailing address).
   Once you have initialized the `*mail*' buffer this way, sending the
mail goes as usual (*note Sending Mail::.).  You can edit the
presupplied header fields if they are not right for you.
   One additional Mail mode command is available when mailing is invoked
from Rmail: `C-c C-y' (`mail-yank-original') inserts into the outgoing
message a copy of the current Rmail message; normally this is the
message you are replying to, but you can also switch to the Rmail
buffer, select a different message, switch back, and yank new current
message.  Normally the yanked message is indented four spaces and has
most header fields deleted from it; an argument to `C-c C-y' specifies
the amount to indent, and `C-u C-c C-y' does not indent at all and does
not delete any header fields.
   Another frequent reason to send mail in Rmail is to forward the
current message to other users.  `f' (`rmail-forward') makes this easy
by preinitializing the `*mail*' buffer with the current message as the
text, and a subject designating a forwarded message.  All you have to
do is fill in the recipients and send.
   The `m' (`rmail-mail') command is used to start editing an outgoing
message that is not a reply.  It leaves the header fields empty. Its
only difference from `C-x 4 m' is that it makes the Rmail buffer
accessible for `C-c y', just as `r' does.  Thus, `m' can be used to
reply to or forward a message; it can do anything `r' or `f' can do.
   The `c' (`rmail-continue') command resumes editing the `*mail*'
buffer, to finish editing an outgoing message you were already
composing, or to alter a message you have sent.
File: emacs,  Node: Rmail Editing,  Next: Rmail Digest,  Prev: Rmail Reply,  Up: Rmail
Editing Within a Message
========================
   Rmail mode provides a few special commands for moving within and
editing the current message.  In addition, the usual Emacs commands are
available (except for a few, such as `C-M-n' and `C-M-h', that are
redefined by Rmail for other purposes).  However, the Rmail buffer is
normally read-only, and to alter it you must use the Rmail command `w'
described below.
     Toggle display of original headers (`rmail-toggle-headers').
     Edit current message (`rmail-edit-current-message').
   Rmail reformats the header of each message before displaying it.
Normally this involves deleting most header fields, on the grounds that
they are not interesting.  The variable `rmail-ignored-headers' should
contain a regexp that matches the header fields to discard in this way.
The original headers are saved permanently, and to see what they look
like, use the `t' (`rmail-toggle-headers') command.  This discards the
reformatted headers of the current message and displays it with the
original headers. Repeating `t' reformats the message again.  Selecting
the message again also reformats.
   The Rmail buffer is normally read only, and most of the characters
you would type to modify it (including most letters) are redefined as
Rmail commands.  This is usually not a problem since it is rare to want
to change the text of a message.  When you do want to do this, the way
is to type `w' (`rmail-edit-current-message'), which changes from Rmail
mode into Rmail Edit mode, another major mode which is nearly the same
as Text mode. The mode line illustrates this change.
   In Rmail Edit mode, letters insert themselves as usual and the Rmail
commands are not available.  When you are finished editing the message
and are ready to go back to Rmail, type `C-c C-c', which switches back
to Rmail mode.  Alternatively, you can return to Rmail mode but cancel
all the editing that you have done by typing `C-c C-]'.
   Entering Rmail Edit mode calls with no arguments the value of the
variable `text-mode-hook', if that value exists and is not `nil'; then
it does the same with the variable `rmail-edit-mode-hook'.  It adds the
attribute `edited' to the message.
File: emacs,  Node: Rmail Digest,  Prev: Rmail Editing,  Up: Rmail
Digest Messages
===============
   A "digest message" is a message which exists to contain and carry
several other messages.  Digests are used on moderated mailing lists;
all the messages that arrive for the list during a period of time such
as one day are put inside a single digest which is then sent to the
subscribers. Transmitting the single digest uses much less computer
time than transmitting the individual messages even though the total
size is the same, because the per-message overhead in network mail
transmission is considerable.
   When you receive a digest message, the most convenient way to read
it is to "undigestify" it: to turn it back into many individual
messages. Then you can read and delete the individual messages as it
suits you.
   To undigestify a message, select it and then type `M-x
undigestify-rmail-message'.  This copies each submessage as a separate
Rmail message and inserts them all following the digest.  The digest
message itself is flagged as deleted.
File: emacs,  Node: Recursive Edit,  Next: Narrowing,  Prev: Rmail,  Up: Top
Recursive Editing Levels
========================
   A "recursive edit" is a situation in which you are using Emacs
commands to perform arbitrary editing while in the middle of another
Emacs command.  For example, when you type `C-r' inside of a
`query-replace', you enter a recursive edit in which you can change the
current buffer.  On exiting from the recursive edit, you go back to the
`query-replace'.
   "Exiting" the recursive edit means returning to the unfinished
command, which continues execution.  For example, exiting the recursive
edit requested by `C-r' in `query-replace' causes query replacing to
resume.  Exiting is done with `C-M-c' (`exit-recursive-edit').
   You can also "abort" the recursive edit.  This is like exiting, but
also quits the unfinished command immediately.  Use the command `C-]'
(`abort-recursive-edit') for this.  *Note Quitting::.
   The mode line shows you when you are in a recursive edit by
displaying square brackets around the parentheses that always surround
the major and minor mode names.  Every window's mode line shows this,
in the same way, since being in a recursive edit is true of Emacs as a
whole rather than any particular buffer.
   It is possible to be in recursive edits within recursive edits.  For
example, after typing `C-r' in a `query-replace', you might type a
command that entered the debugger.  In such circumstances, two or more
sets of square brackets appear in the mode line.  Exiting the inner
recursive edit (such as, with the debugger `c' command) would resume
the command where it called the debugger.  After the end of this
command, you would be able to exit the first recursive edit.  Aborting
also gets out of only one level of recursive edit; it returns
immediately to the command level of the previous recursive edit.  So
you could immediately abort that one too.
   Alternatively, the command `M-x top-level' aborts all levels of
recursive edits, returning immediately to the top level command reader.
   The text being edited inside the recursive edit need not be the same
text that you were editing at top level.  It depends on what the
recursive edit is for.  If the command that invokes the recursive edit
selects a different buffer first, that is the buffer you will edit
recursively.  In any case, you can switch buffers within the recursive
edit in the normal manner (as long as the buffer-switching keys have
not been rebound).  You could probably do all the rest of your editing
inside the recursive edit, visiting files and all.  But this could have
surprising effects (such as stack overflow) from time to time.  So
remember to exit or abort the recursive edit when you no longer need it.
   In general, GNU Emacs tries to avoid using recursive edits.  It is
usually preferable to allow the user to switch among the possible
editing modes in any order he likes.  With recursive edits, the only
way to get to another state is to go "back" to the state that the
recursive edit was invoked from.
File: emacs,  Node: Narrowing,  Next: Sorting,  Prev: Recursive Edit,  Up: Top
Narrowing
=========
   "Narrowing" means focusing in on some portion of the buffer, making
the rest temporarily invisible and inaccessible.  Cancelling the
narrowing, and making the entire buffer once again visible, is called
"widening". The amount of narrowing in effect in a buffer at any time
is called the buffer's "restriction".
`C-x n'
     Narrow down to between point and mark (`narrow-to-region').
`C-x w'
     Widen to make the entire buffer visible again (`widen').
   When you have narrowed down to a part of the buffer, that part
appears to be all there is.  You can't see the rest, you can't move
into it (motion commands won't go outside the visible part), you can't
change it in any way.  However, it is not gone, and if you save the
file all the invisible text will be saved.  In addition to sometimes
making it easier to concentrate on a single subroutine or paragraph by
eliminating clutter, narrowing can be used to restrict the range of
operation of a replace command or repeating keyboard macro.  The word
`Narrow' appears in the mode line whenever narrowing is in effect.
   The primary narrowing command is `C-x n' (`narrow-to-region'). It
sets the current buffer's restrictions so that the text in the current
region remains visible but all text before the region or after the
region is invisible.  Point and mark do not change.
   Because narrowing can easily confuse users who do not understand it,
`narrow-to-region' is normally a disabled command.  Attempting to use
this command asks for confirmation and gives you the option of enabling
it; once you enable the command, confirmation will no longer be
required for it.  *Note Disabling::.
   The way to undo narrowing is to widen with `C-x w' (`widen'). This
makes all text in the buffer accessible again.
   You can get information on what part of the buffer you are narrowed
down to using the `C-x =' command.  *Note Position Info::.
File: emacs,  Node: Sorting,  Next: Shell,  Prev: Narrowing,  Up: Top
Sorting Text
============
   Emacs provides several commands for sorting text in the buffer.  All
operate on the contents of the region (the text between point and the
mark).  They divide the text of the region into many "sort records",
identify a "sort key" for each record, and then reorder the records
into the order determined by the sort keys.  The records are ordered so
that their keys are in alphabetical order, or, for numeric sorting, in
numeric order.  In alphabetic sorting, all upper case letters `A'
through `Z' come before lower case `a', in accord with the ASCII
character sequence.
   The various sort commands differ in how they divide the text into
sort records and in which part of each record is used as the sort key.
Most of the commands make each line a separate sort record, but some
commands use paragraphs or pages as sort records.  Most of the sort
commands use each entire sort record as its own sort key, but some use
only a portion of the record as the sort key.
`M-x sort-lines'
     Divide the region into lines, and sort by comparing the entire
     text of a line.  A prefix argument means sort into descending
     order.
`M-x sort-paragraphs'
     Divide the region into paragraphs, and sort by comparing the entire
     text of a paragraph (except for leading blank lines).  A prefix
     argument means sort into descending order.
`M-x sort-pages'
     Divide the region into pages, and sort by comparing the entire
     text of a page (except for leading blank lines).  A prefix
     argument means sort into descending order.
`M-x sort-fields'
     Divide the region into lines, and sort by comparing the contents of
     one field in each line.  Fields are defined as separated by
     whitespace, so the first run of consecutive non-whitespace
     characters in a line constitutes field 1, the second such run
     constitutes field 2, etc.
     You specify which field to sort by with a numeric argument: 1 to
     sort by field 1, etc.  A negative argument means sort into
     descending order.  Thus, minus 2 means sort by field 2 in
     reverse-alphabetical order.
`M-x sort-numeric-fields'
     Like `M-x sort-fields' except the specified field is converted to
     a number for each line, and the numbers are compared.  `10' comes
     before `2' when considered as text, but after it when considered
     as a number.
`M-x sort-columns'
     Like `M-x sort-fields' except that the text within each line used
     for comparison comes from a fixed range of columns.  See below for
     an explanation.
   For example, if the buffer contains
     On systems where clash detection (locking of files being edited) is
     implemented, Emacs also checks the first time you modify a buffer
     whether the file has changed on disk since it was last visited or
     saved.  If it has, you are asked to confirm that you want to change
     the buffer.
then if you apply `M-x sort-lines' to the entire buffer you get
     On systems where clash detection (locking of files being edited) is
     implemented, Emacs also checks the first time you modify a buffer
     saved.  If it has, you are asked to confirm that you want to change
     the buffer.
     whether the file has changed on disk since it was last visited or
where the upper case `O' comes before all lower case letters.  If you
apply instead `C-u 2 M-x sort-fields' you get
     implemented, Emacs also checks the first time you modify a buffer
     saved.  If it has, you are asked to confirm that you want to change
     the buffer.
     On systems where clash detection (locking of files being edited) is
     whether the file has changed on disk since it was last visited or
where the sort keys were `Emacs', `If', `buffer', `systems' and `the'.
   `M-x sort-columns' requires more explanation.  You specify the
columns by putting point at one of the columns and the mark at the other
column.  Because this means you cannot put point or the mark at the
beginning of the first line to sort, this command uses an unusual
definition of `region': all of the line point is in is considered part
of the region, and so is all of the line the mark is in.
   For example, to sort a table by information found in columns 10 to
15, you could put the mark on column 10 in the first line of the table,
and point on column 15 in the last line of the table, and then use this
command. Or you could put the mark on column 15 in the first line and
point on column 10 in the last line.
   This can be thought of as sorting the rectangle specified by point
and the mark, except that the text on each line to the left or right of
the rectangle moves along with the text inside the rectangle. *Note
Rectangles::.
File: emacs,  Node: Shell,  Next: Hardcopy,  Prev: Sorting,  Up: Top
Running Shell Commands from Emacs
=================================
   Emacs has commands for passing single command lines to inferior shell
processes; it can also run a shell interactively with input and output
to an Emacs buffer `*shell*'.
`M-!'
     Run a specified shell command line and display the output
     (`shell-command').
`M-|'
     Run a specified shell command line with region contents as input;
     optionally replace the region with the output
     (`shell-command-on-region').
`M-x shell'
     Run a subshell with input and output through an Emacs buffer. You
     can then give commands interactively.
* Menu:
* Single Shell::         How to run one shell command and return.
* Interactive Shell::    Permanent shell taking input via Emacs.
* Shell Mode::           Special Emacs commands used with permanent shell.
File: emacs,  Node: Single Shell,  Next: Interactive Shell,  Prev: Shell,  Up: Shell
Single Shell Commands
---------------------
   `M-!' (`shell-command') reads a line of text using the minibuffer
and creates an inferior shell to execute the line as a command.
Standard input from the command comes from the null device.  If the
shell command produces any output, the output goes into an Emacs buffer
named `*Shell Command Output*', which is displayed in another window
but not selected.  A numeric argument, as in `M-1 M-!', directs this
command to insert any output into the current buffer.  In that case,
point is left before the output and the mark is set after the output.
   `M-|' (`shell-command-on-region') is like `M-!' but passes the
contents of the region as input to the shell command, instead of no
input.  If a numeric argument is used, meaning insert output in the
current buffer, then the old region is deleted first and the output
replaces it as the contents of the region.
   Both `M-!' and `M-|' use `shell-file-name' to specify the shell to
use.  This variable is initialized based on your `SHELL' environment
variable when Emacs is started.  If the file name does not specify a
directory, the directories in the list `exec-path' are searched; this
list is initialized based on the environment variable `PATH' when Emacs
is started.  Your `.emacs' file can override either or both of these
default initializations.
   With `M-!' and `M-|', Emacs has to wait until the shell command
completes.  You can quit with `C-g'; that terminates the shell command.
File: emacs,  Node: Interactive Shell,  Next: Shell Mode,  Prev: Single Shell,  Up: Shell
Interactive Inferior Shell
--------------------------
   To run a subshell interactively, putting its typescript in an Emacs
buffer, use `M-x shell'.  This creates (or reuses) a buffer named
`*shell*' and runs a subshell with input coming from and output going
to that buffer.  That is to say, any "terminal output" from the subshell
will go into the buffer, advancing point, and any "terminal input" for
the subshell comes from text in the buffer.  To give input to the
subshell, go to the end of the buffer and type the input, terminated by
   Emacs does not wait for the subshell to do anything.  You can switch
windows or buffers and edit them while the shell is waiting, or while
it is running a command.  Output from the subshell waits until Emacs
has time to process it; this happens whenever Emacs is waiting for
keyboard input or for time to elapse.
   If you would like multiple subshells, change the name of buffer
`*shell*' to something different by using `M-x rename-buffer'.  The
next use of `M-x shell' will create a new buffer `*shell*' with its own
subshell.  By renaming this buffer as well you can create a third one,
and so on.  All the subshells run independently and in parallel.
   The file name used to load the subshell is the value of the variable
`explicit-shell-file-name', if that is non-`nil'.  Otherwise, the
environment variable `ESHELL' is used, or the environment variable
`SHELL' if there is no `ESHELL'.  If the file name specified is
relative, the directories in the list `exec-path' are searched (*note
Single Shell Commands: Single Shell.).
   As soon as the subshell is started, it is sent as input the contents
of the file `~/.emacs_SHELLNAME', if that file exists, where SHELLNAME
is the name of the file that the shell was loaded from. For example, if
you use `csh', the file sent to it is `~/.emacs_csh'.
   `cd', `pushd' and `popd' commands given to the inferior shell are
watched by Emacs so it can keep the `*shell*' buffer's default
directory the same as the shell's working directory.  These commands
are recognized syntactically by examining lines of input that are sent.
 If you use aliases for these commands, you can tell Emacs to recognize
them also.  For example, if the value of the variable
`shell-pushd-regexp' matches the beginning of a shell command line,
that line is regarded as a `pushd' command.  Change this variable when
you add aliases for `pushd'.  Likewise, `shell-popd-regexp' and
`shell-cd-regexp' are used to recognize commands with the meaning of
`popd' and `cd'.  These commands are recognized only at the beginning
of a shell command line.
   If Emacs gets an error while trying to handle what it believes is a
`cd', `pushd' or `popd' command, and the value of
`shell-set-directory-error-hook' is non-`nil', that value is called as
a function with no arguments.
File: emacs,  Node: Shell Mode,  Prev: Interactive Shell,  Up: Shell
Shell Mode
----------
   The shell buffer uses Shell mode, which defines several special keys
attached to the `C-c' prefix.  They are chosen to resemble the usual
editing and job control characters present in shells that are not under
Emacs, except that you must type `C-c' first.  Here is a complete list
of the special key bindings of Shell mode:
`RET'
     At end of buffer send line as input; otherwise, copy current line
     to end of buffer and send it (`send-shell-input').  When a line is
     copied, any text at the beginning of the line that matches the
     variable `shell-prompt-pattern' is left out; this variable's value
     should be a regexp string that matches the prompts that you use in
     your subshell.
`C-c C-d'
     Send end-of-file as input, probably causing the shell or its
     current subjob to finish (`shell-send-eof').
`C-c C-u'
     Kill all text that has yet to be sent as input
     (`kill-shell-input').
`C-c C-w'
     Kill a word before point (`backward-kill-word').
`C-c C-c'
     Interrupt the shell or its current subjob if any
     (`interrupt-shell-subjob').
`C-c C-z'
     Stop the shell or its current subjob if any (`stop-shell-subjob').
`C-c C-\'
     Send quit signal to the shell or its current subjob if any
     (`quit-shell-subjob').
`C-c C-o'
     Delete last batch of output from shell (`kill-output-from-shell').
`C-c C-r'
     Scroll top of last batch of output to top of window
     (`show-output-from-shell').
`C-c C-y'
     Copy the previous bunch of shell input, and insert it into the
     buffer before point (`copy-last-shell-input').  No final newline
     is inserted, and the input copied is not resubmitted until you type
     RET.
File: emacs,  Node: Hardcopy,  Next: Dissociated Press,  Prev: Shell,  Up: Top
Hardcopy Output
===============
   The Emacs commands for making hardcopy derive their names from the
Unix commands `print' and `lpr'.
`M-x print-buffer'
     Print hardcopy of current buffer using Unix command `print' (`lpr
     -p').  This makes page headings containing the file name and page
     number.
`M-x lpr-buffer'
     Print hardcopy of current buffer using Unix command `lpr'. This
     makes no page headings.
`M-x print-region'
     Like `print-buffer' but prints only the current region.
`M-x lpr-region'
     Like `lpr-buffer' but prints only the current region.
   All the hardcopy commands pass extra switches to the `lpr' program
based on the value of the variable `lpr-switches'.  Its value should be
a list of strings, each string a switch starting with `-'.  For
example, the value could be `("-Pfoo")' to print on printer `foo'.
File: emacs,  Node: Dissociated Press,  Next: Amusements,  Prev: Hardcopy,  Up: Top
Dissociated Press
=================
   `M-x dissociated-press' is a command for scrambling a file of text
either word by word or character by character.  Starting from a buffer
of straight English, it produces extremely amusing output.  The input
comes from the current Emacs buffer.  Dissociated Press writes its
output in a buffer named `*Dissociation*', and redisplays that buffer
after every couple of lines (approximately) to facilitate reading it.
   `dissociated-press' asks every so often whether to continue
operating.  Answer `n' to stop it.  You can also stop at any time by
typing `C-g'.  The dissociation output remains in the `*Dissociation*'
buffer for you to copy elsewhere if you wish.
   Dissociated Press operates by jumping at random from one point in the
buffer to another.  In order to produce plausible output rather than
gibberish, it insists on a certain amount of overlap between the end of
one run of consecutive words or characters and the start of the next.
That is, if it has just printed out `president' and then decides to
jump to a different point in the file, it might spot the `ent' in
`pentagon' and continue from there, producing `presidentagon'.  Long
sample texts produce the best results.
   A positive argument to `M-x dissociated-press' tells it to operate
character by character, and specifies the number of overlap characters.
 A negative argument tells it to operate word by word and specifies the
number of overlap words.  In this mode, whole words are treated as the
elements to be permuted, rather than characters.  No argument is
equivalent to an argument of two.  For your againformation, the output
goes only into the buffer `*Dissociation*'.  The buffer you start with
is not changed.
   Dissociated Press produces nearly the same results as a Markov chain
based on a frequency table constructed from the sample text.  It is,
however, an independent, ignoriginal invention.  Dissociated Press
techniquitously copies several consecutive characters from the sample
between random choices, whereas a Markov chain would choose randomly for
each word or character.  This makes for more plausible sounding results,
and runs faster.
   It is a mustatement that too much use of Dissociated Press can be a
developediment to your real work.  Sometimes to the point of outragedy.
And keep dissociwords out of your documentation, if you want it to be
well userenced and properbose.  Have fun.  Your buggestions are welcome.
File: emacs,  Node: Amusements,  Next: Emulation,  Prev: Dissociated Press,  Up: Top
Other Amusements
================
   If you are a little bit bored, you can try `M-x hanoi'.  If you are
considerably bored, give it a numeric argument.  If you are very very
bored, try an argument of 9.  Sit back and watch.
   When you are frustrated, try the famous Eliza program.  Just do `M-x
doctor'.  End each input by typing `RET' twice.
   When you are feeling strange, type `M-x yow'.
File: emacs,  Node: Emulation,  Next: Customization,  Prev: Amusements,  Up: Top
Emulation
=========
   GNU Emacs can be programmed to emulate (more or less) most other
editors.  Standard facilities can emulate these:
EDT (DEC VMS editor)
     Turn on EDT emulation with `M-x edt-emulation-on'.  `M-x
     edt-emulation-off' restores normal Emacs command bindings.
     Most of the EDT emulation commands are keypad keys, and most
     standard Emacs key bindings are still available.  The EDT
     emulation rebindings are done in the global keymap, so there is no
     problem switching buffers or major modes while in EDT emulation.
Gosling Emacs
     Turn on emulation of Gosling Emacs (aka Unipress Emacs) with `M-x
     set-gosmacs-bindings'.  This redefines many keys, mostly on the
     `C-x' and `ESC' prefixes, to work as they do in Gosmacs. `M-x
     set-gnu-bindings' returns to normal GNU Emacs by rebinding the
     same keys to the definitions they had at the time `M-x
     set-gosmacs-bindings' was done.
     It is also possible to run Mocklisp code written for Gosling Emacs.
     *Note Mocklisp::.
vi (Berkeley Unix editor)
     Turn on vi emulation with `M-x vi-mode'.  This is a major mode
     that replaces the previously established major mode.  All of the
     vi commands that, in real vi, enter "input" mode are programmed in
     the Emacs emulator to return to the previous major mode.  Thus,
     ordinary Emacs serves as vi's "input" mode.
     Because vi emulation works through major modes, it does not work
     to switch buffers during emulation.  Return to normal Emacs first.
     If you plan to use vi emulation much, you probably want to bind a
     key to the `vi-mode' command.
vi (alternate emulator)
     Another vi emulator said to resemble real vi more thoroughly is
     invoked by `M-x vip-mode'.  "Input" mode in this emulator is
     changed from ordinary Emacs so you can use ESC to go back to
     emulated vi command mode.  To get from emulated vi command mode
     back to ordinary Emacs, type `C-z'.
     This emulation does not work through major modes, and it is
     possible to switch buffers in various ways within the emulator.
     It is not so necessary to assign a key to the command `vip-mode' as
     it is with `vi-mode' because terminating insert mode does not use
     it.
     For full information, see the long comment at the beginning of the
     source file, which is `lisp/vip.el' in the Emacs distribution.
   I am interested in hearing which vi emulator users prefer, as well
as in receiving more complete user documentation for either or both
emulators. Warning: loading both at once may cause name conficts; no
one has checked.