This is Info file ../info/emacs, produced by Makeinfo-1.54 from the input file emacs.texi. File: emacs, Node: Apropos, Next: Library Keywords, Prev: Name Help, Up: Help Apropos ======= A more sophisticated sort of question to ask is, "What are the commands for working with files?" To ask this question, type `C-h a file RET', which displays a list of all command names that contain `file', including `copy-file', `find-file', and so on. With each command name appears a brief description of how to use the command, and what keys you can currently invoke it with. For example, it would say that you can invoke `find-file' by typing `C-x C-f'. The `a' in `C-h a' stands for `Apropos'; `C-h a' runs the command `command-apropos'. Because `C-h a' looks only for functions whose names contain the string which you specify, you must use ingenuity in choosing the string. If you are looking for commands for killing backwards and `C-h a kill-backwards RET' doesn't reveal any, don't give up. Try just `kill', or just `backwards', or just `back'. Be persistent. Also note that you can use a regular expression as the argument, for more flexibility (*note Regexps::.). Here is a set of arguments to give to `C-h a' that covers many classes of Emacs commands, since there are strong conventions for naming the standard Emacs commands. By giving you a feel for the naming conventions, this set should also serve to aid you in developing a technique for picking `apropos' strings. char, line, word, sentence, paragraph, region, page, sexp, list, defun, rect, buffer, frame, window, file, dir, register, mode, beginning, end, forward, backward, next, previous, up, down, search, goto, kill, delete, mark, insert, yank, fill, indent, case, change, set, what, list, find, view, describe. To list all Lisp symbols that contain a match for a regexp, not just the ones that are defined as commands, use the command `M-x apropos' instead of `C-h a'. This command does not check key bindings by default; specify a numeric argument if you want it to check them. The `super-apropos' command is like `apropos' except that it searches documentation strings as well as symbol names for matches for the specified regular expression. File: emacs, Node: Library Keywords, Next: Misc Help, Prev: Apropos, Up: Help Keyword Search for Lisp Libraries ================================= The `C-h p' command lets you search the standard Emacs Lisp libraries by topic keywords. Here is a partial list of keywords you can `abbrev' Abbreviation handling, typing shortcuts, macros. `bib' Support for the bibliography processor `bib'. C and C++ language support. `calendar' Calendar and time management support. `comm' Communications, networking, remote access to files. `docs' Support for Emacs documentation. `emulations' Emulations of other editors. `extensions' Emacs Lisp language extensions. `faces' Support for using faces (fonts and colors; *note Faces::.). `games' Games, jokes and amusements. `hardware' Support for interfacing with exotic hardware. `help' Support for on-line help systems. `i18n' Internationalization and alternate character-set support. `internal' Code for Emacs internals, build process, defaults. `languages' Specialized modes for editing programming languages. `lisp' Support for using Lisp (including Emacs Lisp). `local' Libraries local to your site. `maint' Maintenance aids for the Emacs development group. `mail' Modes for electronic-mail handling. `news' Support for netnews reading and posting. `non-text' Support for editing files that are not ordinary text. `processes' Process, subshell, compilation, and job control support. `terminals' Support for terminal types. `tex' Support for the TeX formatter. `tools' Programming tools. `unix' Front-ends/assistants for, or emulators of, Unix features. `vms' Support code for VMS. Word processing. File: emacs, Node: Misc Help, Prev: Library Keywords, Up: Help Other Help Commands =================== `C-h i' (`info') runs the Info program, which is used for browsing through structured documentation files. The entire Emacs manual is available within Info. Eventually all the documentation of the GNU system will be available. Type `h' after entering Info to run a tutorial on using Info. There are two special help commands for accessing Emacs documentation through Info. `C-h C-f FUNCTION RET' enters Info and goes straight to the documentation of the Emacs function FUNCTION. `C-h C-k KEY' enters Info and goes straight to the documentation of the key KEY. These two keys run the commands `Info-goto-emacs-command-node' and `Info-goto-emacs-key-command-node'. If something surprising happens, and you are not sure what commands you typed, use `C-h l' (`view-lossage'). `C-h l' prints the last 100 command characters you typed in. If you see commands that you don't know, you can use `C-h c' to find out what they do. Emacs has numerous major modes, each of which redefines a few keys and makes a few other changes in how editing works. `C-h m' (`describe-mode') prints documentation on the current major mode, which normally describes all the commands that are changed in this mode. `C-h b' (`describe-bindings') and `C-h s' (`describe-syntax') present other information about the current Emacs mode. `C-h b' displays a list of all the key bindings now in effect; the local bindings defined by the current minor modes first, then the local bindings defined by the current major mode, and finally the global bindings (*note Key Bindings::.). `C-h s' displays the contents of the syntax table, with explanations of each character's syntax (*note Syntax::.). The other `C-h' options display various files of useful information. `C-h C-w' displays the full details on the complete absence of warranty for GNU Emacs. `C-h n' (`view-emacs-news') displays the file `emacs/etc/NEWS', which contains documentation on Emacs changes arranged chronologically. `C-h t' (`help-with-tutorial') displays the learn-by-doing Emacs tutorial. `C-h C-c' (`describe-copying') displays the file `emacs/etc/COPYING', which tells you the conditions you must obey in distributing copies of Emacs. `C-h C-d' (`describe-distribution') displays the file `emacs/etc/DISTRIB', which tells you how you can order a copy of the latest version of Emacs. File: emacs, Node: Mark, Next: Killing, Prev: Help, Up: Top The Mark and the Region *********************** There are many Emacs commands which operate on an arbitrary contiguous part of the current buffer. To specify the text for such a command to operate on, you set "the mark" at one end of it, and move point to the other end. The text between point and the mark is called "the region". You can move point or the mark to adjust the boundaries of the region. It doesn't matter which one is set first chronologically, or which one comes earlier in the text. Once the mark has been set, it remains where you put it until it is set again at another place. The mark remains fixed with respect to the preceding character if text is inserted or deleted in the buffer. Each Emacs buffer has its own mark, so that when you return to a buffer that had been selected previously, it has the same mark it had before. Many commands that insert text, such as `C-y' (`yank') and `M-x insert-buffer', position point and the mark at opposite ends of the inserted text, so that the region contains the text just inserted. Aside from delimiting the region, the mark is also useful for remembering a spot that you may want to go back to. To make this feature more useful, each buffer remembers 16 previous locations of the mark in the "mark ring". * Menu: * Setting Mark:: Commands to set the mark. * Transient Mark:: How to make Emacs highlight the region- when there is one. * Using Region:: Summary of ways to operate on contents of the region. * Marking Objects:: Commands to put region around textual units. * Mark Ring:: Previous mark positions saved so you can go back there. File: emacs, Node: Setting Mark, Next: Transient Mark, Up: Mark Setting the Mark ================ Here are some commands for setting the mark: `C-SPC' Set the mark where point is (`set-mark-command'). `C-@' The same. `C-x C-x' Interchange mark and point (`exchange-point-and-mark'). For example, suppose you wish to convert part of the buffer to all upper-case, using the `C-x C-u' (`upcase-region') command which operates on the text in the region. You can first go to the beginning of the text to be capitalized, type `C-SPC' to put the mark there, move to the end, and then type `C-x C-u'. Or, you can set the mark at the end of the text, move to the beginning, and then type `C-x C-u'. The most common way to set the mark is with the `C-SPC' command (`set-mark-command'). This sets the mark where point is. Then you can move point away, leaving the mark behind. Ordinary terminals have only one cursor, so there is no way for Emacs to show you where the mark is located. You have to remember. The usual solution to this problem is to set the mark and then use it soon, before you forget where it is. Alternatively, you can see where the mark is with the command `C-x C-x' (`exchange-point-and-mark') which puts the mark where point was and point where the mark was. The extent of the region is unchanged, but the cursor and point are now at the previous position of the mark. `C-x C-x' is also useful when you are satisfied with the position of point but want to move the mark; do `C-x C-x' to put point at that end of the region, and then move it. A second use of `C-x C-x', if necessary, puts the mark at the new position with point back at its original position. There is no such character as `C-SPC' in ASCII; when you type SPC while holding down CTRL, what you get on most ordinary terminals is the character `C-@'. This key is actually bound to `set-mark-command'. But unless you are unlucky enough to have a terminal where typing `C-SPC' does not produce `C-@', you might as well think of this character as `C-SPC'. Under X, `C-SPC' is actually a distinct character, but its binding is still `set-mark-command'. File: emacs, Node: Transient Mark, Next: Using Region, Prev: Setting Mark, Up: Mark Transient Mark Mode =================== Many Emacs commands move the mark and invisibly set new regions. This means that there is almost always some region that you can act on. This is convenient, provided you get used to keeping track of the mark's position. Some people prefer a more rigid mode of operation in which you must set up a region for each command that uses one--in which the region "lasts" only temporarily. This is called Transient Mark mode. It is particularly well-suited to window systems such as X, since Emacs can highlight the region when it is active. To enable Transient Mark mode, type `M-x transient-mark-mode'. This command toggles the mode, so you can issue it again to return to the normal Emacs way of handling the mark and the region. Here are the details of Transient Mark mode: * To set the mark, type `C-SPC' (`set-mark-command'). This makes the mark active; as you move point, you will see the region highlighting change in extent. * On a window system, an easy way to select a region is to press the button Mouse-1 (normally the left button) at one end of it, drag the mouse to the other end, and then release the button. * When the mark is active, you can execute any commands you want on the region, such as killing, indentation, or writing to a file. * Any change to the buffer, such as inserting or deleting a character, deactivates the mark. This means any subsequent command that operates on a region will get an error and refuse to operate. You can make the region active again by typing `C-x C-x'. * Commands like `M->' that "leave the mark behind" do not activate the new mark. it. You can activate the new region by executing `C-x C-x' (`exchange-point-and-mark'). * Quitting with `C-g' deactivates the mark. Transient Mark mode is also sometimes known as "Zmacs mode" because the Zmacs editor on the MIT Lisp Machine handled the mark in a similar When multiple windows show the same buffer, they can have different regions, because they can have different values of point. In Transient Mark mode, each window highlights its own region. The part that is highlighted in the selected window is the region that editing commands use. *Note Windows::. File: emacs, Node: Using Region, Next: Marking Objects, Prev: Transient Mark, Up: Mark Operating on the Region ======================= Once you have set up a region and the mark is active, you can do many things to the text in it: * Kill it with `C-w' (*note Killing::.). * Save it in a register with `C-x r s' (*note Registers::.). * Save it in a buffer or a file (*note Accumulating Text::.). * Convert case with `C-x C-l' or `C-x C-u' (*note Case::.). * Indent it with `C-x TAB' or `C-M-\' (*note Indentation::.). * Fill it as text with `M-x fill-region' (*note Filling::.). * Print hardcopy with `M-x print-region' (*note Hardcopy::.). * Evaluate it as Lisp code with `M-x eval-region' (*note Lisp Eval::.). Most commands that operate on the text in the region have the word `region' in their names. File: emacs, Node: Marking Objects, Next: Mark Ring, Prev: Using Region, Up: Mark Commands to Mark Textual Objects ================================ Here are the commands for placing point and the mark around a textual object such as a word, list, paragraph or page. `M-@' Set mark after end of next word (`mark-word'). This command and the following one do not move point. `C-M-@' Set mark after end of next Lisp expression (`mark-sexp'). `M-h' Put region around current paragraph (`mark-paragraph'). `C-M-h' Put region around current Lisp defun (`mark-defun'). `C-x h' Put region around entire buffer (`mark-whole-buffer'). `C-x C-p' Put region around current page (`mark-page'). `M-@' (`mark-word') puts the mark at the end of the next word, while `C-M-@' (`mark-sexp') puts it at the end of the next Lisp expression. These commands handle arguments just like `M-f' and `C-M-f'. Other commands set both point and mark, to delimit an object in the buffer. For example, `M-h' (`mark-paragraph') moves point to the beginning of the paragraph that surrounds or follows point, and puts the mark at the end of that paragraph (*note Paragraphs::.). It prepares the region so you can indent, case-convert, or kill a whole paragraph. `C-M-h' (`mark-defun') similarly puts point before and the mark after the current or following defun (*note Defuns::.). `C-x C-p' (`mark-page') puts point before the current page, and mark at the end (*note Pages::.). The mark goes after the terminating page delimiter (to include it), while point goes after the preceding page delimiter (to exclude it). A numeric argument specifies a later page (if positive) or an earlier page (if negative) instead of the current page. Finally, `C-x h' (`mark-whole-buffer') sets up the entire buffer as the region, by putting point at the beginning and the mark at the end. File: emacs, Node: Mark Ring, Prev: Marking Objects, Up: Mark The Mark Ring ============= Aside from delimiting the region, the mark is also useful for remembering a spot that you may want to go back to. To make this feature more useful, each buffer remembers 16 previous locations of the mark, in the "mark ring". Commands that set the mark also push the old mark onto this ring. To return to a marked location, use `C-u C-SPC' (or `C-u C-@'); this is the command `set-mark-command' given a numeric argument. It moves point to where the mark was, and restores the mark from the ring of former marks. Thus, repeated use of this command moves point to all of the old marks on the ring, one by one. The mark positions you move through in this way are not lost; they go to the end of the ring. Each buffer has its own mark ring. All editing commands use the current buffer's mark ring. In particular, `C-u C-SPC' always stays in the same buffer. Many commands that can move long distances, such as `M-<' (`beginning-of-buffer'), start by setting the mark and saving the old mark on the mark ring. This is to make it easier for you to move back later. Searches set the mark if they move point. You can tell when a command sets the mark because it displays `Mark Set' in the echo area. If you want to move back to the same place over and over, the mark ring may not be convenient enough. If so, you can record the position in a register for later retrieval (*note RegPos::.). The variable `mark-ring-max' specifies the maximum number of entries to keep in the mark ring. If that many entries exist and another one is pushed, the last one in the list is discarded. Repeating `C-u C-SPC' circulates through the positions currently in the ring. The variable `mark-ring' holds the mark ring itself, as a list of marker objects in the order most recent first. This variable is local in every buffer. File: emacs, Node: Killing, Next: Yanking, Prev: Mark, Up: Top Deletion and Killing ==================== Most commands which erase text from the buffer save it in the kill ring so that you can move or copy it to other parts of the buffer. These commands are known as "kill" commands. The rest of the commands that erase text do not save it in the kill ring; they are known as "delete" commands. (This distinction is made only for erasure of text in the buffer.) If you do a kill or delete command by mistake, you can use the `C-x u' (`undo') command to undo it (*note Undo::.). The delete commands include `C-d' (`delete-char') and DEL (`delete-backward-char'), which delete only one character at a time, and those commands that delete only spaces or newlines. Commands that can destroy significant amounts of nontrivial data generally kill. The commands' names and individual descriptions use the words `kill' and `delete' to say which they do. You can use kill commands in read-only buffers. They don't actually change the buffer, and they beep to warn you of that, but they do copy the text you tried to kill into the kill ring, so you can yank it into other buffers. * Menu: * Deletion:: Commands for deleting small amounts of text and blank areas. * Killing by Lines:: How to kill entire lines of text at one time. * Other Kill Commands:: Commands to kill large regions of text and syntactic units such as words and sentences. File: emacs, Node: Deletion, Next: Killing by Lines, Up: Killing Deletion -------- `C-d' Delete next character (`delete-char'). `DEL' Delete previous character (`delete-backward-char'). `M-\' Delete spaces and tabs around point (`delete-horizontal-space'). `M-SPC' Delete spaces and tabs around point, leaving one space (`just-one-space'). `C-x C-o' Delete blank lines around the current line (`delete-blank-lines'). `M-^' Join two lines by deleting the intervening newline, along with any indentation following it (`delete-indentation'). The most basic delete commands are `C-d' (`delete-char') and DEL (`delete-backward-char'). `C-d' deletes the character after point, the one the cursor is "on top of". This doesn't move point. DEL deletes the character before the cursor, and moves point back. You can delete newlines like any other characters in the buffer; deleting a newline joins two lines. Actually, `C-d' and DEL aren't always delete commands; when given arguments, they kill instead, since they can erase more than one character this way. The other delete commands are those which delete only whitespace characters: spaces, tabs and newlines. `M-\' (`delete-horizontal-space') deletes all the spaces and tab characters before and after point. `M-SPC' (`just-one-space') does likewise but leaves a single space after point, regardless of the number of spaces that existed previously (even zero). `C-x C-o' (`delete-blank-lines') deletes all blank lines after the current line. If the current line is blank, it deletes all blank lines preceding the current line as well (leaving one blank line, the current line). `M-^' (`delete-indentation') joins the current line and the previous line, by deleting a newline and all surrounding spaces, usually leaving a single space. *Note M-^: Indentation. File: emacs, Node: Killing by Lines, Next: Other Kill Commands, Prev: Deletion, Up: Killing Killing by Lines ---------------- `C-k' Kill rest of line or one or more lines (`kill-line'). The simplest kill command is `C-k'. If given at the beginning of a line, it kills all the text on the line, leaving it blank. When used on a blank line, it kills the whole line including its newline. To kill an entire non-blank line, go to the beginning and type `C-k' twice. More generally, `C-k' kills from point up to the end of the line, unless it is at the end of a line. In that case it kills the newline following point, thus merging the next line into the current one. Spaces and tabs that you can't see at the end of the line are ignored when deciding which case applies, so if point appears to be at the end of the line, you can be sure `C-k' will kill the newline. When `C-k' is given a positive argument, it kills that many lines and the newlines that follow them (however, text on the current line before point is spared). With a negative argument -N, it kills N lines preceding the current line (together with the text on the current line before point). Thus, `C-u - 2 C-k' at the front of a line kills the two previous lines. `C-k' with an argument of zero kills the text before point on the current line. If the variable `kill-whole-line' is non-`nil', `C-k' at the very beginning of a line kills the entire line including the following newline. This variable is normally `nil'. File: emacs, Node: Other Kill Commands, Prev: Killing by Lines, Up: Killing Other Kill Commands ------------------- `C-w' Kill region (from point to the mark) (`kill-region'). `M-d' Kill word (`kill-word'). *Note Words::. `M-DEL' Kill word backwards (`backward-kill-word'). `C-x DEL' Kill back to beginning of sentence (`backward-kill-sentence'). *Note Sentences::. `M-k' Kill to end of sentence (`kill-sentence'). `C-M-k' Kill sexp (`kill-sexp'). *Note Lists::. `M-z CHAR' Kill through the next occurrence of CHAR (`zap-to-char'). A kill command which is very general is `C-w' (`kill-region'), which kills everything between point and the mark. With this command, you can kill any contiguous sequence of characters, if you first set the region around them. A convenient way of killing is combined with searching: `M-z' (`zap-to-char') reads a character and kills from point up to (and including) the next occurrence of that character in the buffer. A numeric argument acts as a repeat count. A negative argument means to search backward and kill text before point. Other syntactic units can be killed: words, with `M-DEL' and `M-d' (*note Words::.); sexps, with `C-M-k' (*note Lists::.); and sentences, with `C-x DEL' and `M-k' (*note Sentences::.). File: emacs, Node: Yanking, Next: Accumulating Text, Prev: Killing, Up: Top Yanking ======= "Yanking" means reinserting text previously killed. This is what some systems call "pasting". The usual way to move or copy text is to kill it and then yank it elsewhere one or more times. `C-y' Yank last killed text (`yank'). `M-y' Replace text just yanked with an earlier batch of killed text (`yank-pop'). `M-w' Save region as last killed text without actually killing it (`kill-ring-save'). `C-M-w' Append next kill to last batch of killed text (`append-next-kill'). * Menu: * Kill Ring:: Where killed text is stored. Basic yanking. * Appending Kills:: Several kills in a row all yank together. * Earlier Kills:: Yanking something killed some time ago. File: emacs, Node: Kill Ring, Next: Appending Kills, Up: Yanking The Kill Ring ------------- All killed text is recorded in the "kill ring", a list of blocks of text that have been killed. There is only one kill ring, used in all buffers, so you can kill text in one buffer and yank it in another buffer. This is the usual way to move text from one file to another. (*Note Accumulating Text::, for some other ways.) The command `C-y' (`yank') reinserts the text of the most recent kill. It leaves the cursor at the end of the text. It sets the mark at the beginning of the text. *Note Mark::. `C-u C-y' leaves the cursor in front of the text, and sets the mark after it. This is only if the argument is specified with just a `C-u', precisely. Any other sort of argument, including `C-u' and digits, specifies an earlier kill to yank (*note Earlier Kills::.). If you wish to copy a block of text, you might want to use `M-w' (`kill-ring-save'), which copies the region into the kill ring without removing it from the buffer. This is approximately equivalent to `C-w' followed by `C-x u', except that `M-w' does not alter the undo history and does not temporarily change the screen. File: emacs, Node: Appending Kills, Next: Earlier Kills, Prev: Kill Ring, Up: Yanking Appending Kills --------------- Normally, each kill command pushes a new entry onto the kill ring. However, two or more kill commands in a row combine their text into a single entry, so that a single `C-y' gets it all back as it was before it was killed. Thus, if you want to yank text as a unit, you need not kill all of it with one command; you can keep killing line after line, or word after word, until you have killed it all, and you can still get it all back at once. Commands that kill forward from point add onto the end of the previous killed text. Commands that kill backward from point add text onto the beginning. This way, any sequence of mixed forward and backward kill commands puts all the killed text into one entry without rearrangement. Numeric arguments do not break the sequence of appending kills. For example, suppose the buffer contains This is a line -!-of sample text. with point as shown. If you type `M-d M-DEL M-d M-DEL', killing alternately forward and backward, you end up with `a line of sample' as one entry in the kill ring, and `This is text.' in the buffer. (Note the double space, which you can clean up with `M-SPC' or `M-q'.) Another way to kill the same text is to move back two words with `M-b M-b', then kill all four words forward with `C-u M-d'. This produces exactly the same results in the buffer and in the kill ring. `M-f M-f C-u M-DEL' kills the same text, all going backward; once again, the result is the same. The text in the kill ring entry always has the same order that it had in the buffer before you killed it. If a kill command is separated from the last kill command by other commands (not just numeric arguments), it starts a new entry on the kill ring. But you can force it to append by first typing the command `C-M-w' (`append-next-kill') right before it. The `C-M-w' tells the following command, if it is a kill command, to append the text it kills to the last killed text, instead of starting a new entry. With `C-M-w', you can kill several separated pieces of text and accumulate them to be yanked back in one place. File: emacs, Node: Earlier Kills, Prev: Appending Kills, Up: Yanking Yanking Earlier Kills --------------------- To recover killed text that is no longer the most recent kill, use the `M-y' command (`yank-pop'). It takes the text previously yanked and replaces it with the text from an earlier kill. So, to recover the text of the next-to-the-last kill, first use `C-y' to yank the last kill, and then use `M-y' to replace it with the previous kill. `M-y' is allowed only after a `C-y' or another `M-y'. You can understand `M-y' in terms of a "last yank" pointer which points at an entry in the kill ring. Each time you kill, the "last yank" pointer moves to the newly made entry at the front of the ring. `C-y' yanks the entry which the "last yank" pointer points to. `M-y' moves the "last yank" pointer to a different entry, and the text in the buffer changes to match. Enough `M-y' commands can move the pointer to any entry in the ring, so you can get any entry into the buffer. Eventually the pointer reaches the end of the ring; the next `M-y' moves it to the first entry again. `M-y' moves the "last yank" pointer around the ring, but it does not change the order of the entries in the ring, which always runs from the most recent kill at the front to the oldest one still remembered. `M-y' can take a numeric argument, which tells it how many entries to advance the "last yank" pointer by. A negative argument moves the pointer toward the front of the ring; from the front of the ring, it moves "around" to the last entry and continues forward from there. Once the text you are looking for is brought into the buffer, you can stop doing `M-y' commands and it will stay there. It's just a copy of the kill ring entry, so editing it in the buffer does not change what's in the ring. As long as no new killing is done, the "last yank" pointer remains at the same place in the kill ring, so repeating `C-y' will yank another copy of the same previous kill. If you know how many `M-y' commands it would take to find the text you want, you can yank that text in one step using `C-y' with a numeric argument. `C-y' with an argument restores the text the specified number of entries back in the kill ring. Thus, `C-u 2 C-y' gets the next to the last block of killed text. It is equivalent to `C-y M-y'. `C-y' with a numeric argument starts counting from the "last yank" pointer, and sets the "last yank" pointer to the entry that it yanks. The length of the kill ring is controlled by the variable `kill-ring-max'; no more than that many blocks of killed text are saved. The actual contents of the kill ring are stored in a variable named `kill-ring'; you can view the entire contents of the kill ring with the command `C-h v kill-ring'. File: emacs, Node: Accumulating Text, Next: Rectangles, Prev: Yanking, Up: Top Accumulating Text ================= Usually we copy or move text by killing it and yanking it, but there are other methods convenient for copying one block of text in many places, or for copying many scattered blocks of text into one place. To copy one block to many places, store it in a register (*note Registers::.). Here we describe the commands to accumulate scattered pieces of text into a buffer or into a file. `M-x append-to-buffer' Append region to contents of specified buffer. `M-x prepend-to-buffer' Prepend region to contents of specified buffer. `M-x copy-to-buffer' Copy region into specified buffer, deleting that buffer's old contents. `M-x insert-buffer' Insert contents of specified buffer into current buffer at point. `M-x append-to-file' Append region to contents of specified file, at the end. To accumulate text into a buffer, use `M-x append-to-buffer'. This reads a buffer name, them inserts a copy of the region into the buffer specified. If you specify a nonexistent buffer, `append-to-buffer' creates the buffer. The text is inserted wherever point is in that buffer. If you have been using the buffer for editing, the copied text goes into the middle of the text of the buffer, wherever point happens to be in it. Point in that buffer is left at the end of the copied text, so successive uses of `append-to-buffer' accumulate the text in the specified buffer in the same order as they were copied. Strictly speaking, `append-to-buffer' does not always append to the text already in the buffer--only if point in that buffer is at the end. However, if `append-to-buffer' is the only command you use to alter a buffer, then point is always at the end. `M-x prepend-to-buffer' is just like `append-to-buffer' except that point in the other buffer is left before the copied text, so successive prependings add text in reverse order. `M-x copy-to-buffer' is similar except that any existing text in the other buffer is deleted, so the buffer is left containing just the text newly copied into it. To retrieve the accumulated text from another buffer, use `M-x insert-buffer'; this too takes BUFFERNAME as an argument. It inserts a copy of the text in buffer BUFFERNAME into the selected buffer. You can alternatively select the other buffer for editing, then optionally move text from it by killing. *Note Buffers::, for background information on buffers. Instead of accumulating text within Emacs, in a buffer, you can append text directly into a file with `M-x append-to-file', which takes FILENAME as an argument. It adds the text of the region to the end of the specified file. The file is changed immediately on disk. You should use `append-to-file' only with files that are *not* being visited in Emacs. Using it on a file that you are editing in Emacs would change the file behind Emacs's back, which can lead to losing some of your editing. File: emacs, Node: Rectangles, Next: Registers, Prev: Accumulating Text, Up: Top Rectangles ========== The rectangle commands operate on rectangular areas of the text: all the characters between a certain pair of columns, in a certain range of lines. Commands are provided to kill rectangles, yank killed rectangles, clear them out, fill them with blanks or text, or delete them. Rectangle commands are useful with text in multicolumn formats, and for changing text into or out of such formats. When you must specify a rectangle for a command to work on, you do it by putting the mark at one corner and point at the opposite corner. The rectangle thus specified is called the "region-rectangle" because you control it in about the same way the region is controlled. But remember that a given combination of point and mark values can be interpreted either as a region or as a rectangle, depending on the command that uses them. If point and the mark are in the same column, the rectangle they delimit is empty. If they are in the same line, the rectangle is one line high. This asymmetry between lines and columns comes about because point (and likewise the mark) is between two columns, but within a line. `C-x r k' Kill the text of the region-rectangle, saving its contents as the "last killed rectangle" (`kill-rectangle'). `C-x r y' Yank the last killed rectangle with its upper left corner at point (`yank-rectangle'). `C-x r o' Insert blank space to fill the space of the region-rectangle (`open-rectangle'). This pushes the previous contents of the region-rectangle rightward. `M-x delete-rectangle' Delete the text of the region-rectangle without saving it in any special way. `M-x clear-rectangle' Clear the region-rectangle by replacing its contents with spaces. `M-x string-rectangle RET STRING RET' Insert STRING on each line of the region-rectangle. The rectangle operations fall into two classes: commands deleting and inserting rectangles, and commands for blank rectangles. There are two ways to get rid of the text in a rectangle: you can discard the text (delete it) or save it as the "last killed" rectangle. The commands for these two ways are `M-x delete-rectangle' and `C-x r k' (`kill-rectangle'). In either case, the portion of each line that falls inside the rectangle's boundaries is deleted, causing following text (if any) on the line to move left into the gap. Note that "killing" a rectangle is not killing in the usual sense; the rectangle is not stored in the kill ring, but in a special place that can only record the most recent rectangle killed. This is because yanking a rectangle is so different from yanking linear text that different yank commands have to be used and yank-popping is hard to make sense of. Yanking a rectangle is the opposite of killing one. Point specifies where to put the rectangle's upper left corner. The rectangle's first line is inserted there, the rectangle's second line is inserted at a point one line vertically down, and so on. The number of lines affected is determined by the height of the saved rectangle. To yank the last killed rectangle, type `C-x r y' (`yank-rectangle'). This can be used to convert single-column lists into double-column lists; kill the second half of the list as a rectangle and then yank it beside the first line of the list. You can also copy rectangles into and out of registers with `C-x r r R' and `C-x r i R'. *Note Rectangle Registers: RegRect. The command `M-x string-rectangle' is similar to `C-x r o', but it inserts a specified string instead of blanks. You specify the string with the minibuffer. Since the length of the string specifies how many columns to insert, the width of the region-rectangle does not matter for this command. What does matter is the position of the left edge (which specifies the column position for the insertion in each line) and the range of lines that the rectangle occupies. The previous contents of the text after the insertion column are pushed rightward. There are two commands for making with blank rectangles: `M-x clear-rectangle' to blank out existing text, and `C-x r o' (`open-rectangle') to insert a blank rectangle. Clearing a rectangle is equivalent to deleting it and then inserting a blank rectangle of the same size. File: emacs, Node: Registers, Next: Display, Prev: Rectangles, Up: Top Registers ********* Emacs "registers" are places you can save text or positions for later use. Text and rectangles saved in registers can be copied into the buffer once or many times; you can move point to a position saved in a register. Each register has a name which is a single character. A register can store a piece of text, a rectangle, a position, a window configuration or a file name, but only one thing at any given time. Whatever you store in a register remains there until you store something else in that register. To see what a register R contains, use `M-x view-register'. `M-x view-register RET R' Display a description of what register R contains. * Menu: * Position: RegPos. Saving positions in registers. * Text: RegText. Saving text in registers. * Rectangle: RegRect. Saving rectangles in registers. * Configurations: RegConfig. Saving window configurations in registers. * Files: RegFiles. File names in registers. File: emacs, Node: RegPos, Next: RegText, Up: Registers Saving Positions in Registers ============================= Saving a position records a spot in a buffer so that you can move back there later. Moving to a saved position reselects that buffer and moves point to that spot. `C-x r SPC R' Save position of point in register R (`point-to-register'). `C-x r j R' Jump to the position saved in register R (`jump-to-register'). To save the current position of point in a register, choose a name R and type `C-x r SPC R'. The register R retains the position thus saved until you store something else in that register. The command `C-x r j R' moves point to the position recorded in register R. The register is not affected; it continues to record the same position. You can jump to the same position using the same register any number of times. File: emacs, Node: RegText, Next: RegRect, Prev: RegPos, Up: Registers Saving Text in Registers ======================== When you want to insert a copy of the same piece of text several times, it may be inconvenient to yank it from the kill ring, since each subsequent kill moves that entry further down the ring. An alternative is to store the text in a register with `C-x r s' (`copy-to-register') and then retrieve it with `C-x r i' (`insert-register'). `C-x r s R' Copy region into register R (`copy-to-register'). `C-x r i R' Insert text from register R (`insert-register'). `C-x r s R' stores a copy of the text of the region into the register named R. Given a numeric argument, `C-x r s R' deletes the text from the buffer as well. `C-x r i R' inserts in the buffer the text from register R. Normally it leaves point before the text and places the mark after, but with a numeric argument (`C-u') it puts point after the text and the mark before. File: emacs, Node: RegRect, Next: RegConfig, Prev: RegText, Up: Registers Saving Rectangles in Registers ============================== A register can contain a rectangle instead of linear text. The rectangle is represented as a list of strings. *Note Rectangles::, for basic information on how to specify a rectangle in the buffer. `C-x r r R' Copy the region-rectangle into register R (`copy-region-to-rectangle'). With numeric argument, delete it as well. `C-x r i R' Insert the rectangle stored in register R (if it contains a rectangle) (`insert-register'). The `C-x r i R' command inserts a text string if the register contains one, and inserts a rectangle if the register contains one. File: emacs, Node: RegConfig, Next: RegFiles, Prev: RegRect, Up: Registers Saving Window Configurations in Registers ========================================= You can save the window configuration of the selected frame in a register, or even the configuration of all frames, and restore the configuration later. `C-x r w R' Save the state of the selected frame's windows in register R (`window-configuration-to-register'). `C-x r f R' Save the state of all windows in all frames in register R (`frame-configuration-to-register'). Use `C-x r j R' to restore a window or frame configuration. This is the same command used to restore a cursor position. File: emacs, Node: RegFiles, Prev: RegConfig, Up: Registers Keeping File Names in Registers =============================== If you visit certain file names frequently, you can visit them more conveniently if you put their names in registers. Here's the Lisp code used to put a file name in a register: (set-register ?R '(file . NAME)) For example, (set-register ?z '(file . "/gd/gnu/emacs/19.0/src/ChangeLog")) puts the file name shown in register `z'. To visit the file whose name is in register R, type `C-x r j R'. (This is the same command used to jump to a position or restore a frame configuration.) File: emacs, Node: Display, Next: Search, Prev: Registers, Up: Top Controlling the Display *********************** Since only part of a large buffer fits in the window, Emacs tries to show the part that is likely to be interesting. The display control commands allow you to specify which part of the text you want to see. `C-l' Clear screen and redisplay, scrolling the selected window to center point vertically within it (`recenter'). `C-v' Scroll forward (a windowful or a specified number of lines) (`scroll-up'). `NEXT' Likewise, scroll forward. `M-v' Scroll backward (`scroll-down'). `PRIOR' Likewise, scroll backward. `ARG C-l' Scroll so point is on line ARG (`recenter'). `C-x <' Scroll text in current window to the left (`scroll-left'). `C-x >' Scroll to the right (`scroll-right'). `C-x $' Make deeply indented lines invisible (`set-selective-display'). The names of all scroll commands are based on the direction that the text moves in the window. Thus, the command to scrolling forward is called `scroll-up', since the text moves up. * Menu: * Scrolling:: Moving text up and down in a window. * Horizontal Scrolling:: Moving text left and right in a window. * Selective Display:: Hiding lines with lots of indentation. * Optional Display:: Optional display features. * European Display:: Displaying (and inputting) European characters. * Display Vars:: Information on variables for customizing display. File: emacs, Node: Scrolling, Next: Horizontal Scrolling, Up: Display Scrolling ========= If a buffer contains text that is too large to fit entirely within a window that is displaying the buffer, Emacs shows a contiguous portion of the text. The portion shown always contains point. "Scrolling" means moving text up or down in the window so that different parts of the text are visible. Scrolling forward means that text moves up, and new text appears at the bottom. Scrolling backward moves text down and new text appears at the top. Scrolling happens automatically if you move point past the bottom or top of the window. You can also explicitly request scrolling with the commands in this section. `C-l' Clear screen and redisplay, scrolling the selected window to center point vertically within it (`recenter'). `C-v' Scroll forward (a windowful or a specified number of lines) (`scroll-up'). `NEXT' Likewise, scroll forward. `M-v' Scroll backward (`scroll-down'). `PRIOR' Likewise, scroll backward. `ARG C-l' Scroll so point is on line ARG (`recenter'). `C-M-l' Scroll heuristically to bring useful information onto the screen (`reposition-window'). The most basic scrolling command is `C-l' (`recenter') with no argument. It clears the entire screen and redisplays all windows. In addition, it scrolls the selected window so that point is halfway down from the top of the window. The scrolling commands `C-v' and `M-v' let you move all the text in the window up or down a few lines. `C-v' (`scroll-up') with an argument shows you that many more lines at the bottom of the window, moving the text and point up together as `C-l' might. `C-v' with a negative argument shows you more lines at the top of the window. `M-v' (`scroll-down') is like `C-v', but moves in the opposite direction. The function keys NEXT and PRIOR are equivalent to `C-v' and `M-v'. To read the buffer a windowful at a time, use `C-v' with no argument. It takes the last two lines at the bottom of the window and puts them at the top, followed by nearly a whole windowful of lines not previously visible. If point was in the text scrolled off the top, it moves to the new top of the window. `M-v' with no argument moves backward with overlap similarly. The number of lines of overlap across a `C-v' or `M-v' is controlled by the variable `next-screen-context-lines'; by default, it is two. Another way to do scrolling is with `C-l' with a numeric argument. `C-l' does not clear the screen when given an argument; it only scrolls the selected window. With a positive argument N, it repositions text to put point N lines down from the top. An argument of zero puts point on the very top line. Point does not move with respect to the text; rather, the text and point move rigidly on the screen. `C-l' with a negative argument puts point that many lines from the bottom of the window. For example, `C-u - 1 C-l' puts point on the bottom line, and `C-u - 5 C-l' puts it five lines from the bottom. Just `C-u' as argument, as in `C-u C-l', scrolls point to the center of the screen. The `C-M-l' command (`reposition-window') scrolls the current window heuristically in a way designed to get useful information onto the screen. For example, in a Lisp file, this command tries to get the entire current defun onto the screen if possible. Scrolling happens automatically if point has moved out of the visible portion of the text when it is time to display. Usually the scrolling is done so as to put point vertically centered within the window. However, if the variable `scroll-step' has a nonzero value, an attempt is made to scroll the buffer by that many lines; if that is enough to bring point back into visibility, that is what is done.