-\1f
-File: xemacs.info, Node: Position Info, Next: Arguments, Prev: Continuation Lines, Up: Basic
-
-Cursor Position Information
-===========================
-
- If you are accustomed to other display editors, you may be surprised
-that Emacs does not always display the page number or line number of
-point in the mode line. In Emacs, this information is only rarely
-needed, and a number of commands are available to compute and print it.
-Since text is stored in a way that makes it difficult to compute the
-information, it is not displayed all the time.
-
-`M-x what-page'
- Print page number of point, and line number within page.
-
-`M-x what-line'
- Print line number of point in the buffer.
-
-`M-x line-number-mode'
- Toggle automatic display of current line number.
-
-`M-='
- Print number of lines and characters in the current region
- (`count-lines-region'). *Note Mark::, for information about the
- region.
-
-`C-x ='
- Print character code of character after point, character position
- of point, and column of point (`what-cursor-position').
-
- There are several commands for printing line numbers:
-
- * `M-x what-line' counts lines from the beginning of the file and
- prints the line number point is on. The first line of the file is
- line number 1. You can use these numbers as arguments to `M-x
- goto-line'.
-
- * `M-x what-page' counts pages from the beginning of the file, and
- counts lines within the page, printing both of them. *Note
- Pages::, for the command `C-x l', which counts the lines in the
- current page.
-
- * `M-=' (`count-lines-region') prints the number of lines in the
- region (*note Mark::). *Note Pages::, for the command `C-x l'
- which counts the lines in the
-
- The command `C-x =' (`what-cursor-position') can be used to find out
-the column that the cursor is in, and other miscellaneous information
-about point. It prints a line in the echo area that looks like this:
-
- Char: c (0143, 99, 0x63) point=18862 of 24800(76%) column 53
-
-(In fact, this is the output produced when point is before `column 53'
-in the example.)
-
- The four values after `Char:' describe the character that follows
-point, first by showing it and then by giving its character code in
-octal, decimal and hex.
-
- `point=' is followed by the position of point expressed as a
-character count. The front of the buffer counts as position 1, one
-character later as 2, and so on. The next, larger number is the total
-number of characters in the buffer. Afterward in parentheses comes the
-position expressed as a percentage of the total size.
-
- `column' is followed by the horizontal position of point, in columns
-from the left edge of the window.
-
- If the buffer has been narrowed, making some of the text at the
-beginning and the end temporarily invisible, `C-x =' prints additional
-text describing the current visible range. For example, it might say:
-
- Char: c (0143, 99, 0x63) point=19674 of 24575(80%) <19591 - 19703> column 69
-
-where the two extra numbers give the smallest and largest character
-position that point is allowed to assume. The characters between those
-two positions are the visible ones. *Note Narrowing::.
-
- If point is at the end of the buffer (or the end of the visible
-part), `C-x =' omits any description of the character after point. The
-output looks like
-
- point=563026 of 563025(100%) column 0
-
-\1f
-File: xemacs.info, Node: Arguments, Prev: Position Info, Up: Basic
-
-Numeric Arguments
-=================
-
- In mathematics and computer usage, the word "argument" means "data
-provided to a function or operation." Any Emacs command can be given a
-"numeric argument" (also called a "prefix argument"). Some commands
-interpret the argument as a repetition count. For example, giving an
-argument of ten to the key `C-f' (the command `forward-char', move
-forward one character) moves forward ten characters. With these
-commands, no argument is equivalent to an argument of one. Negative
-arguments are allowed. Often they tell a command to move or act in
-the opposite direction.
-
- If your keyboard has a <META> key (labelled with a diamond on
-Sun-type keyboards and labelled `Alt' on some other keyboards), the
-easiest way to specify a numeric argument is to type digits and/or a
-minus sign while holding down the <META> key. For example,
- M-5 C-n
-
-would move down five lines. The characters `Meta-1', `Meta-2', and so
-on, as well as `Meta--', do this because they are keys bound to
-commands (`digit-argument' and `negative-argument') that are defined to
-contribute to an argument for the next command. Digits and `-'
-modified with Control, or Control and Meta, also specify numeric
-arguments.
-
- Another way of specifying an argument is to use the `C-u'
-(`universal-argument') command followed by the digits of the argument.
-With `C-u', you can type the argument digits without holding down
-modifier keys; `C-u' works on all terminals. To type a negative
-argument, type a minus sign after `C-u'. Just a minus sign without
-digits normally means -1.
-
- `C-u' followed by a character which is neither a digit nor a minus
-sign has the special meaning of "multiply by four". It multiplies the
-argument for the next command by four. `C-u' twice multiplies it by
-sixteen. Thus, `C-u C-u C-f' moves forward sixteen characters. This
-is a good way to move forward "fast", since it moves about 1/5 of a line
-in the usual size frame. Other useful combinations are `C-u C-n', `C-u
-C-u C-n' (move down a good fraction of a frame), `C-u C-u C-o' (make "a
-lot" of blank lines), and `C-u C-k' (kill four lines).
-
- Some commands care only about whether there is an argument and not
-about its value. For example, the command `M-q' (`fill-paragraph') with
-no argument fills text; with an argument, it justifies the text as well.
-(*Note Filling::, for more information on `M-q'.) Just `C-u' is a
-handy way of providing an argument for such commands.
-
- Some commands use the value of the argument as a repeat count, but do
-something peculiar when there is no argument. For example, the command
-`C-k' (`kill-line') with argument N kills N lines, including their
-terminating newlines. But `C-k' with no argument is special: it kills
-the text up to the next newline, or, if point is right at the end of
-the line, it kills the newline itself. Thus, two `C-k' commands with
-no arguments can kill a non-blank line, just like `C-k' with an
-argument of one. (*Note Killing::, for more information on `C-k'.)
-
- A few commands treat a plain `C-u' differently from an ordinary
-argument. A few others may treat an argument of just a minus sign
-differently from an argument of -1. These unusual cases are described
-when they come up; they are always for reasons of convenience of use of
-the individual command.
-
- You can use a numeric argument to insert multiple copies of a
-character. This is straightforward unless the character is a digit; for
-example, `C-u 6 4 a' inserts 64 copies of the character `a'. But this
-does not work for inserting digits; `C-u 6 4 1' specifies an argument
-of 641, rather than inserting anything. To separate the digit to
-insert from the argument, type another `C-u'; for example, `C-u 6 4 C-u
-1' does insert 64 copies of the character `1'.
-
- We use the term "prefix argument" as well as "numeric argument" to
-emphasize that you type the argument before the command, and to
-distinguish these arguments from minibuffer arguments that come after
-the command.
-
-\1f
-File: xemacs.info, Node: Undo, Next: Minibuffer, Prev: Basic, Up: Top
-
-Undoing Changes
-***************
-
- Emacs allows you to undo all changes you make to the text of a
-buffer, up to a certain amount of change (8000 characters). Each
-buffer records changes individually, and the undo command always
-applies to the current buffer. Usually each editing command makes a
-separate entry in the undo records, but some commands such as
-`query-replace' make many entries, and very simple commands such as
-self-inserting characters are often grouped to make undoing less
-tedious.
-
-`C-x u'
- Undo one batch of changes (usually, one command's worth) (`undo').
-
-`C-_'
- The same.
-
- The command `C-x u' or `C-_' allows you to undo changes. The first
-time you give this command, it undoes the last change. Point moves to
-the text affected by the undo, so you can see what was undone.
-
- Consecutive repetitions of the `C-_' or `C-x u' commands undo
-earlier and earlier changes, back to the limit of what has been
-recorded. If all recorded changes have already been undone, the undo
-command prints an error message and does nothing.
-
- Any command other than an undo command breaks the sequence of undo
-commands. Starting at this moment, the previous undo commands are
-considered ordinary changes that can themselves be undone. Thus, you
-can redo changes you have undone by typing `C-f' or any other command
-that have no important effect, and then using more undo commands.
-
- If you notice that a buffer has been modified accidentally, the
-easiest way to recover is to type `C-_' repeatedly until the stars
-disappear from the front of the mode line. When that happens, all the
-modifications you made have been canceled. If you do not remember
-whether you changed the buffer deliberately, type `C-_' once. When you
-see Emacs undo the last change you made, you probably remember why you
-made it. If the change was an accident, leave it undone. If it was
-deliberate, redo the change as described in the preceding paragraph.
-
- Whenever an undo command makes the stars disappear from the mode
-line, the buffer contents is the same as it was when the file was last
-read in or saved.
-
- Not all buffers record undo information. Buffers whose names start
-with spaces don't; these buffers are used internally by Emacs and its
-extensions to hold text that users don't normally look at or edit.
-Minibuffers, help buffers, and documentation buffers also don't record
-undo information.
-
- Emacs can remember at most 8000 or so characters of deleted or
-modified text in any one buffer for reinsertion by the undo command.
-There is also a limit on the number of individual insert, delete, or
-change actions that Emacs can remember.
-
- There are two keys to run the `undo' command, `C-x u' and `C-_',
-because on some keyboards, it is not obvious how to type `C-_'. `C-x u'
-is an alternative you can type in the same fashion on any terminal.
-
-\1f
-File: xemacs.info, Node: Minibuffer, Next: M-x, Prev: Undo, Up: Top
-
-The Minibuffer
-**************
-
- The "minibuffer" is the facility used by XEmacs commands to read
-arguments more complicated than a single number. Minibuffer arguments
-can be file names, buffer names, Lisp function names, XEmacs command
-names, Lisp expressions, and many other things, depending on the command
-reading the argument. You can use the usual XEmacs editing commands in
-the minibuffer to edit the argument text.
-
- When the minibuffer is in use, it appears in the echo area, and the
-cursor moves there. The beginning of the minibuffer line displays a
-"prompt" which says what kind of input you should supply and how it
-will be used. Often this prompt is derived from the name of the command
-that the argument is for. The prompt normally ends with a colon.
-
- Sometimes a "default argument" appears in parentheses after the
-colon; it, too, is part of the prompt. The default is used as the
-argument value if you enter an empty argument (e.g., by just typing
-<RET>). For example, commands that read buffer names always show a
-default, which is the name of the buffer that will be used if you type
-just <RET>.
-
- The simplest way to enter a minibuffer argument is to type the text
-you want, terminated by <RET> which exits the minibuffer. You can
-cancel the command that wants the argument, and get out of the
-minibuffer, by typing `C-g'.
-
- Since the minibuffer uses the screen space of the echo area, it can
-conflict with other ways XEmacs customarily uses the echo area. Here is
-how XEmacs handles such conflicts:
-
- * If a command gets an error while you are in the minibuffer, this
- does not cancel the minibuffer. However, the echo area is needed
- for the error message and therefore the minibuffer itself is
- hidden for a while. It comes back after a few seconds, or as soon
- as you type anything.
-
- * If in the minibuffer you use a command whose purpose is to print a
- message in the echo area, such as `C-x =', the message is printed
- normally, and the minibuffer is hidden for a while. It comes back
- after a few seconds, or as soon as you type anything.
-
- * Echoing of keystrokes does not take place while the minibuffer is
- in use.
-
-* Menu:
-
-* File: Minibuffer File. Entering file names with the minibuffer.
-* Edit: Minibuffer Edit. How to edit in the minibuffer.
-* Completion:: An abbreviation facility for minibuffer input.
-* Minibuffer History:: Reusing recent minibuffer arguments.
-* Repetition:: Re-executing commands that used the minibuffer.
-